I believe that Wim can be the best person to decide this issue of formalities
for new members as he was the one one who started this group. A better
alternative would be to have a set of resource materials which shall include the
exchange of information/emails before on various issues (a bunch of info by now)
raised every now and then by new and old members. New members can be referred to
this materials for them to download and familiarize with it.
james mansphilippines

--- On Sun, 11/22/09, Denton Craig <ve3hjv@...> wrote:

From: Denton Craig <ve3hjv@...>
Subject: Re: {Disarmed} [microhydro] Intro message for newcomers
To: microhydro@yahoogroups.com
Date: Sunday, November 22, 2009, 12:00 PM
















 









       Hi Manfred:

This is excellent, well written and very thoughtfull.

Thanks for putting it forward.

Nando is getting a little crotchey in his old age.



Kindest regards,

Denton Craig

Ottawa Canada

ve3hjv



Dear all, and specially Wim, Nando,

>

> in this group we frequently get posts from newcomers to microhydro, who

> don't know the very basics, and come here looking to learn them. That's

> normal, good and fine, but old time group members easily get upset by

> all those many posts from newcomers asking the same questions and doing

> the same mistakes (both technical and in netiquette). Like so many, I

> also prefer talking to people with a real name and knowing their

> location, rather than talk to anonymous ghosts, but on the other hand I

> can understand very well that many newcomers don't know this, specially

> because there are many other forums on the web which actively encourage

> anonymous posting and prefer people using an alias rather than their

> name! And it must be mighty shocking to any newcomer who signs up here,

> posts a few basic questions, and then gets shot dead by people demanding

> his name, location and precise measurements of his water resource,

> instead of giving useful advice!

>

> So, I would propose that we keep a sort of "welcome briefing" handy, and

> whenever a newcomer shows up and anonymously says he has a creek and

> thinks it might power his home, farm, town or perhaps much of his

> country, then either the group moderator or anyone else could post this

> briefing, as an introduction and basic help for new members.

>

> As for the contents of this briefing, I would propose the following:

>

> ----------

> Basics about the Microhydro group:

>

> We are a worldwide group of people who are connected in some way to

> small water turbines and everything around them. Many of us have built

> turbines or accessory equipment, others are using microhydro systems

> built by others, while many simply enjoy thinking, writing, reading and

> dreaming about this technology.

>

> We like addressing each other by our real names. Anonymous posting is

> not welcome. Also we like to know where in the world you are located,

> because that is very important for determining suitable technologies,

> applicable laws, and so on.

>

> We like to help newcomers to this technology, as much as we like

> discussing more advanced topics, but we don't like explaining the same

> basics again and again to every new member. So, here comes the second

> part of this briefing:

>

> Basics about microhydro:

>

> The power of water that moves downslope can easily be harvested, and

> either used directly, or (more commonly) converted into electricity.

> When considering any microhydro project, the VERY FIRST thing you have

> to do, is measuring the flow rate (amount of water per unit of time)

> that you can use, in different times of the year, and the head (altitude

> difference between the intake point and the turbine site). Then you can

>   calculate how much power can be extracted, and then decide whether

> it's worth doing this.

>

> The power available is given by simple laws of physics: The head

> multiplied by the flow rate, multiplied by the gravitational constant,

> gives the gross power. Using metric units, no conversion constants of

> any sort are necessary, so that you can multiply the head in meters by

> the flow rate in liters per second, multiply this by the gravitational

> constant of 9.8, to obtain the gross power in watts. The use of

> nonstandard units, such as the English Imperial Units, is not

> recommended, because any calculation using these units requires the use

> of constants, which easily lead to mistakes when being mis-applied.

>

> The net electrical power you can obtain is always lower than the gross

> power. How much lower it is, depends on the losses of each part in the

> system: Filter, penstock, valves, nozzles, turbine, generator,

> transmission system, and possibly some more. An overall efficiency of

> 60% is achievable in a well designed system. Very small systems (less

> than 1000 watts) tend to be less efficient than this, while industrial

> scale systems are typically much more efficient than 60%.

>

> Since examples are always clearer than descriptions, here is an example:

>

> If you have a creek tumbling down a steep slope, and you can take in 10

> liters of water per second at a certain altitude, and return it to the

> creek at an altitude 50 meters lower, placing the turbine at that lower

> location, then the gross power you have available will be 10 * 50 * 9.8

> = 4900 watts, and if your system is well designed and built, you can

> harvest roughly 4900 * 0.6 = 2940 watts of electrical power.

>

> The head and flow rate MUST be measured, NOT estimated. Estimated values

> are completely useless, because even for professionals it's very hard to

> estimate these with any reasonable accuracy.

>

> Relatively long distances between the water intake and the turbine site

> are OK, if a low loss penstock is used. But such long distances sharply

> increase penstock cost. A large head in a small distance makes a

> microhydro system much more cost-effective.

>

> The required minimum penstock diameter is usually larger than what

> newcomers think. A good rule of thumb for an initial estimation of

> penstock diameter is that the flow velocity in the penstock should be

> roughly one meter per second. Basic geometry and math allows calculating

> the flow velocity for any given pipe diameter and flow rate. From this

> approximation, it might be convenient or even necessary to deviate a

> bit, according to the resulting penstock size, and its length.

> Generally, larger penstocks can work at slightly higher flow velocity,

> and long penstocks must be slightly larger than short ones.

>

> Large amounts of water flowing fast, but with almost no available head,

> such as in a large, deep, fast-flowing river, can produce some power,

> but these systems are generally more problematic than a microhydro

> turbine that uses a small amount of water with a large head.

>

> The turbine type is selected depending on the flow rate and head of the

> site, and interacts with the generator selection. The generator in very

> small systems might generate DC, charge batteries, and use either the

> low voltage directly, or convert it to standard line voltage AC in an

> inverter. Larger systems generate AC directly, making them much simpler,

> efficient and more cost-effective. In some cases, in can be convenient

> to connect your microhydro system to the public grid, but in most cases

> this is either not feasible, or not convenient. These decisions will

> come later, once you have gained complete clarity about your site's

> characteristics and power capability.

>

> Magical solutions do not exist. Damming up a creek does not increase the

> average flow rate. There is no turbine that can produce more mechanical

> power than the power available in your water source. There is no gear

> system that can multiply the power. And there is no generator that can

> produce more electrical power than the mechanical power put into it. And

> while a battery system can deliver a power much higher than the power of

> the turbine system, for a short time, it cannot increase the average

> power. In fact, each of these devices looses some energy!

>

> Don't spend any money or work on turbines, generators, penstocks, dams,

> batteries, etc, before you have designed the complete system, based on

> sound measurement of your water resource. If you rush to buy stuff, it's

> highly likely that you will buy the wrong parts for your site, wasting

> your money.

>

> Welcome to the group!

> ------------ --------- --------- --

>

> So, what do you think? What's missing? Should we let loose something

> like this on every newcomer?

>

> Manfred, from the slope of the Llaima volcano in southern Chile.

>

> This message was powered by microhydro.

>

> ============ ========= ===

> Visit my hobby homepage!

> http://ludens. cl

> ============ ========= ===

>

> --

> This message has been scanned for viruses and

> dangerous content by MailScanner, and is

> believed to be clean.

>

>



--

This message has been scanned for viruses and

dangerous content by MailScanner, and is

believed to be clean.






























[Non-text portions of this message have been removed]

Dear Microhydrers,

I am a lurker who has ben following the list for the past 3 years or
so. I live near White River South Africa, and have a small irrigation
canal flowing through my property.  For the past few years I have
been reading posts and learning and have finally got to the point of
getting my own system close to the point of comissioning. The info I
have learned from the list has been INCRDEDIBLE.

I think Manfreds'  "introduction" is great. It answers so many of the
questions I have needed to answer. (I also referred a lot to
Manfred's website before I started designing my system, and want to
thank him for the clear, informative images and explanations he has
there.)

I think this list is an excellent resource, and despite the fact that
ocasionally the "old timers" get irritated with the short-cut answers
requested by newcomers, I want to say a big thank you to everyone who
puts in time and effort, You guys are great!

Mark Attwood
mark@...
www.artprintsa.com





On 23 Nov 2009, at 10:22, microhydro@yahoogroups.com wrote:

> micro hydropower
> Messages In This Digest (6 Messages)
> 1a.
> Re: Intro message for newcomers From: Vinod Ramani
> 1b.
> Re: Intro message for newcomers From: Manfred Mornhinweg
> 2.1.
> Re: Very small scale generators. From: Michael Welch
> 2.2.
> Re: Very small scale generators. From: William Wixon
> 3a.
> Re: Overspeed braking. From: Nento Luki
> 3b.
> Re: Overspeed braking. From: jrkess98@...
> View All Topics | Create New Topic
> Messages
> 1a.
> Re: Intro message for newcomers
> Posted by: "Vinod Ramani" vinodramani@...   vinodramani4
> Sun Nov 22, 2009 2:48 pm (PST)
>
>
>
> Dear All
>
> I agree
>
> No reason to be be rude and intimidating new members.
> Dont we all want more members/knowledge/support ?
> Let us all make this forum very pleasant and open.
>
> We all will benefit with this attitude.
>
> I am a junior member but I feel I can post suggestions.
>
> Vinod Ramani
> India
>
> On Fri, Nov 20, 2009 at 8:17 PM, Manfred Mornhinweg
> <manfred@...>wrote:
>
> >
> >
> > Dear all, and specially Wim, Nando,
> >
> > in this group we frequently get posts from newcomers to
> microhydro, who
> > don't know the very basics, and come here looking to learn them.
> That's
> > normal, good and fine, but old time group members easily get
> upset by
> > all those many posts from newcomers asking the same questions and
> doing
> > the same mistakes (both technical and in netiquette). Like so
> many, I
> > also prefer talking to people with a real name and knowing their
> > location, rather than talk to anonymous ghosts, but on the other
> hand I
> > can understand very well that many newcomers don't know this,
> specially
> > because there are many other forums on the web which actively
> encourage
> > anonymous posting and prefer people using an alias rather than their
> > name! And it must be mighty shocking to any newcomer who signs up
> here,
> > posts a few basic questions, and then gets shot dead by people
> demanding
> > his name, location and precise measurements of his water resource,
> > instead of giving useful advice!
> >
> > So, I would propose that we keep a sort of "welcome briefing"
> handy, and
> > whenever a newcomer shows up and anonymously says he has a creek and
> > thinks it might power his home, farm, town or perhaps much of his
> > country, then either the group moderator or anyone else could
> post this
> > briefing, as an introduction and basic help for new members.
> >
> > As for the contents of this briefing, I would propose the following:
> >
> > ----------
> > Basics about the Microhydro group:
> >
> > We are a worldwide group of people who are connected in some way to
> > small water turbines and everything around them. Many of us have
> built
> > turbines or accessory equipment, others are using microhydro systems
> > built by others, while many simply enjoy thinking, writing,
> reading and
> > dreaming about this technology.
> >
> > We like addressing each other by our real names. Anonymous
> posting is
> > not welcome. Also we like to know where in the world you are
> located,
> > because that is very important for determining suitable
> technologies,
> > applicable laws, and so on.
> >
> > We like to help newcomers to this technology, as much as we like
> > discussing more advanced topics, but we don't like explaining the
> same
> > basics again and again to every new member. So, here comes the
> second
> > part of this briefing:
> >
> > Basics about microhydro:
> >
> > The power of water that moves downslope can easily be harvested, and
> > either used directly, or (more commonly) converted into electricity.
> > When considering any microhydro project, the VERY FIRST thing you
> have
> > to do, is measuring the flow rate (amount of water per unit of time)
> > that you can use, in different times of the year, and the head
> (altitude
> > difference between the intake point and the turbine site). Then
> you can
> > calculate how much power can be extracted, and then decide whether
> > it's worth doing this.
> >
> > The power available is given by simple laws of physics: The head
> > multiplied by the flow rate, multiplied by the gravitational
> constant,
> > gives the gross power. Using metric units, no conversion
> constants of
> > any sort are necessary, so that you can multiply the head in
> meters by
> > the flow rate in liters per second, multiply this by the
> gravitational
> > constant of 9.8, to obtain the gross power in watts. The use of
> > nonstandard units, such as the English Imperial Units, is not
> > recommended, because any calculation using these units requires
> the use
> > of constants, which easily lead to mistakes when being mis-applied.
> >
> > The net electrical power you can obtain is always lower than the
> gross
> > power. How much lower it is, depends on the losses of each part
> in the
> > system: Filter, penstock, valves, nozzles, turbine, generator,
> > transmission system, and possibly some more. An overall
> efficiency of
> > 60% is achievable in a well designed system. Very small systems
> (less
> > than 1000 watts) tend to be less efficient than this, while
> industrial
> > scale systems are typically much more efficient than 60%.
> >
> > Since examples are always clearer than descriptions, here is an
> example:
> >
> > If you have a creek tumbling down a steep slope, and you can take
> in 10
> > liters of water per second at a certain altitude, and return it
> to the
> > creek at an altitude 50 meters lower, placing the turbine at that
> lower
> > location, then the gross power you have available will be 10 * 50
> * 9.8
> > = 4900 watts, and if your system is well designed and built, you can
> > harvest roughly 4900 * 0.6 = 2940 watts of electrical power.
> >
> > The head and flow rate MUST be measured, NOT estimated. Estimated
> values
> > are completely useless, because even for professionals it's very
> hard to
> > estimate these with any reasonable accuracy.
> >
> > Relatively long distances between the water intake and the
> turbine site
> > are OK, if a low loss penstock is used. But such long distances
> sharply
> > increase penstock cost. A large head in a small distance makes a
> > microhydro system much more cost-effective.
> >
> > The required minimum penstock diameter is usually larger than what
> > newcomers think. A good rule of thumb for an initial estimation of
> > penstock diameter is that the flow velocity in the penstock
> should be
> > roughly one meter per second. Basic geometry and math allows
> calculating
> > the flow velocity for any given pipe diameter and flow rate. From
> this
> > approximation, it might be convenient or even necessary to deviate a
> > bit, according to the resulting penstock size, and its length.
> > Generally, larger penstocks can work at slightly higher flow
> velocity,
> > and long penstocks must be slightly larger than short ones.
> >
> > Large amounts of water flowing fast, but with almost no available
> head,
> > such as in a large, deep, fast-flowing river, can produce some
> power,
> > but these systems are generally more problematic than a microhydro
> > turbine that uses a small amount of water with a large head.
> >
> > The turbine type is selected depending on the flow rate and head
> of the
> > site, and interacts with the generator selection. The generator
> in very
> > small systems might generate DC, charge batteries, and use either
> the
> > low voltage directly, or convert it to standard line voltage AC
> in an
> > inverter. Larger systems generate AC directly, making them much
> simpler,
> > efficient and more cost-effective. In some cases, in can be
> convenient
> > to connect your microhydro system to the public grid, but in most
> cases
> > this is either not feasible, or not convenient. These decisions will
> > come later, once you have gained complete clarity about your site's
> > characteristics and power capability.
> >
> > Magical solutions do not exist. Damming up a creek does not
> increase the
> > average flow rate. There is no turbine that can produce more
> mechanical
> > power than the power available in your water source. There is no
> gear
> > system that can multiply the power. And there is no generator
> that can
> > produce more electrical power than the mechanical power put into
> it. And
> > while a battery system can deliver a power much higher than the
> power of
> > the turbine system, for a short time, it cannot increase the average
> > power. In fact, each of these devices looses some energy!
> >
> > Don't spend any money or work on turbines, generators, penstocks,
> dams,
> > batteries, etc, before you have designed the complete system,
> based on
> > sound measurement of your water resource. If you rush to buy
> stuff, it's
> > highly likely that you will buy the wrong parts for your site,
> wasting
> > your money.
> >
> > Welcome to the group!
> > --------------------------------
> >
> > So, what do you think? What's missing? Should we let loose something
> > like this on every newcomer?
> >
> > Manfred, from the slope of the Llaima volcano in southern Chile.
> >
> > This message was powered by microhydro.
> >
> > ========================
> > Visit my hobby homepage!
> > http://ludens.cl
> > ========================
> >
> >
>
> [Non-text portions of this message have been removed]
>
> Back to top
> Reply to sender | Reply to group | Reply via web post
> Messages in this topic (16)
> 1b.
> Re: Intro message for newcomers
> Posted by: "Manfred Mornhinweg" manfred@...   mmornhin
> Sun Nov 22, 2009 2:49 pm (PST)
>
>
>
> Hi John,
>
> > Can you explain how to measure the flow accurately?
>
> For small creeks, probably the best method is capturing the entire
> creek
> with a provisional intake made from a pipe buried in an earthen
> dam, and
> use a stopwatch and a container of known capacity to measure how
> long it
> takes to fill, and do the math.
>
> For larger creeks, probably the best method is making a provisional
> weir
> from a plank, sealed with earth, plastic, stones, whatever, and cut
> a 90
> degree V-shaped notch in it. Then install a stick in the little pond
> that forms behind that weir, with a ruler attached to it, so that it
> shows water heigth above the low corner of the notch. A simple formula
> relates the flow rate to the water height above that corner of the
> notch:
>
> Flow = 1.36 * height^2.5
>
> This is in basic units of the international system, which is,
> height in
> meters and flow in cubic meters per second.
>
> This system is quite precise for a relatively wide range of flows.
>
> And if the flow is more than what can be handled with such a V-shaped
> notch, then leave the plank uncut, so that water overflows it on its
> entire length. Install the ruler so that it measure water height above
> the plank, and use this formula:
>
> Flow = 1.7 * length * height^1.5
>
> This is less accurate than the other one, but good enough if the plank
> is long enough so that the length is many times the water height over
> it. This equation is also in basic units (meters, cubic meters).
>
> The water level ruler must be installed far enough back from the
> weir so
> that it is at a place where the water is not yet going downslope over
> the weir.
>
> With one of these three methods, any water resource apt for microhydro
> can be measured.
>
> And for Don:
>
> I understand concerns about privacy and identity theft, even if I
> don't
> think this is so critical. My position is somewhat fatalistic: The
> really bad guys know everything about me and you, so we are exposed to
> their misdoings, no matter what we do!
>
> But to anyone concerned with privacy to the point of not wanting to
> tell
> his real name, I would dare to suggest to make up a name, but one that
> sounds real, and stick to it. We will then all know that person by
> that
> invented name. He will be Jack Smith to us, even if his real name
> might
> be John Miller. So what, and his real identity stays protected. But if
> he chooses Turbojack as an alias, it will be obvious that that isn't
> his real name, and so some of us will feel like talking to a ghost!
> And
> if he chooses several aliases and switches them all the time, this
> will
> confuse us. The location should be correct, though, even if it
> certainly
> doesn't need to be as detailed as a street address. I suppose that if
> someone tells us he lives in the foothills of the Drakensberg range in
> South Africa, that's precise enough. It allows to place him, and
> possibly to give location-specific advice. It's very different than if
> that person were located near Bern, Switzerland, for example. The
> resources available, the laws, ease to get technological solutions,
> availability of a power grid, and so on, and even the style of doing
> things, are likely to be very different.
>
> I personally have often written to "ghosts", as Nando likes to call
> anonymous posters, and I don't feel so bad about that as he does, but
> really it makes things easier and nicer when one can place the person!
>
> Manfred.
>
> ========================
> Visit my hobby homepage!
> http://ludens.cl
> ========================
>
> Back to top
> Reply to sender | Reply to group | Reply via web post
> Messages in this topic (16)
> 2.1.
> Re: Very small scale generators.
> Posted by: "Michael Welch" michael_welch@...   solar_bozos
> Sun Nov 22, 2009 2:52 pm (PST)
>
>
>
> I do not see how you can practically increase one without the
> other. Just adding more light to the same area of PV cells will
> also increase the heat.
>
> Early in commercial PV history, a rather large utility PV array
> added stainless steel reflective wings on each side of some
> standard modules. Failure rates were higher than expected, and the
> modules started discoloring. The industry learned never to do that
> again.
>
> On the other hand, I have a friend that has had a single Mariposa
> concentrating module in his 12 V system for maybe 15 years, and
> last I heard it was doing fine.
> http://solardyne.stores.yahoo.net/marconmod10k.html
>
> Clifford Krolick/ Back Country Excursions wrote at 06:36 PM
> 11/18/2009:
>
> >Michael
> >
> >All good points. I was hoping to not increase the heat coefficient
> >with the reflection. I'm Not thinking about concentrating the light
> >like a magnifying glass. Just thinking more in line that at a
> >particular the distance away from the photo units there would be
> >little or no thermal transfer just light transfer. But probably this
> >is wishful thinking. What's your take?
> >
> >
> >Cliff
> >Parsonsfield, Maine, USA
> >
> >
> >On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
> >
> >> 1. Adding reflectors will increase the temperature of the PV cells
> >> which will decrease the output. It will also shorten the life of
> the
> >> modules and probably void any warranty.
> >>
> >> 2. Tracking the sun is a good idea if either you have good horizon
> >> to horizon exposure, or if you need to maximize available power
> >> either early or late in the day, like in irrigation pumping
> >> applications. Otherwise, you are probably better off with a fixed
> >> array and spending the tracker money on more modules instead.
> >>
> >> BjornOlaf wrote at 02:02 PM 11/17/2009:
> >>
> >>> I am not so sure reflecting light onto the panels would be that
> >>> effective unless you tracked the sun.... I did however read
> >>> somewhere that tracking the sun with the panel gave about 40% more
> >>> energy than simply having the panel stationary at the optimal noon
> >>> position....
> >>> Â
> >>> Bjorn Justnes
> >>> La Vinzelle
> >>> France
> >>>
> >>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions
> <bcountry@...
> >>> > wrote:
> >>>
> >>>
> >>> From: Clifford Krolick/ Back Country Excursions
> <bcountry@...>
> >>> Subject: Re: [microhydro] Very small scale generators.
> >>> To: microhydro@yahoogroups.com
> >>> Date: Tuesday, November 17, 2009, 5:30 PM
> >>>
> >>>
> >>> Â
> >>>
> >>>
> >>>
> >>> Jb
> >>>
> >>> Certainly for some of us we'll have to do a combination of
> things to
> >>> create enough Electricity. Has any one heard of using reflective
> >>> technology to significantly increase output of photoV panels??
> >>> On Nov 16, 2009, at 6:56 PM, JB wrote:
> >>
> >>
> >>
> >> ------------------------------------
> >>
> >> Does your company feature in the microhydro business directory
> athttp://microhydropower.net/directory
> >> ? If not, please register free of charge and be exposed to the
> >> microhydro community world wide!
> >>
> >> NOTE: The advertisements in this email are added by Yahoogroups who
> >> provides us with free email group services. The microhydro-group
> >> does not endorse products or support the advertisements in any way.
> >>
> >> More information on micro hydropower at http://microhydropower.net
> >>
> >> To unsubscribe: send empty message to microhydro-
> unsubscribe@...
> >> ! Groups Links
> >>
> >>
> >>
> >
> >
> >
> >------------------------------------
> >
> >Does your company feature in the microhydro business directory
> athttp://microhydropower.net/directory ? If not, please register
> free of charge and be exposed to the microhydro community world wide!
> >
> >NOTE: The advertisements in this email are added by Yahoogroups
> who provides us with free email group services. The microhydro-
> group does not endorse products or support the advertisements in
> any way.
> >
> >More information on micro hydropower at http://microhydropower.net
> >
> >To unsubscribe: send empty message to microhydro-
> unsubscribe@...! Groups Links
> >
> >
> >
>
> Back to top
> Reply to sender | Reply to group | Reply via web post
> Messages in this topic (51)
> 2.2.
> Re: Very small scale generators.
> Posted by: "William Wixon" wilwix@...   william_wixon
> Sun Nov 22, 2009 9:56 pm (PST)
>
>
>
> sorry to be diverging from the microhydro topic but this discussion
> about
> reflecting sunlight touched on something i had wondered just the
> other day,
> and had wondered about in the past as well, i'm sure there must be a
> downside or it would already be being done, but i wondered why
> don't people
> put mirrors on a tracking device and just reflect straight sunlight
> into the
> windows of their home for supplimental heat and light (for example,
> on the
> northern side of their homes)? im guessing havnig blinding sunlight
> coming
> in your windows at a low angle would be very distracting and
> uncomfortable,
> and probably it wouldnt make economic sense to have an expensive
> tracker for
> the availble BTU's of reflected sunlight.... etc.
> just wondering.
> has it already been done? would it even be possible to track and aim
> sunlight into a window?
>
> On Sun, Nov 22, 2009 at 1:27 PM, Michael Welch
> <michael_welch@...>wrote:
>
> > I do not see how you can practically increase one without the
> other. Just
> > adding more light to the same area of PV cells will also increase
> the heat.
> >
> > Early in commercial PV history, a rather large utility PV array
> added
> > stainless steel reflective wings on each side of some standard
> modules.
> > Failure rates were higher than expected, and the modules started
> > discoloring. The industry learned never to do that again.
> >
> > On the other hand, I have a friend that has had a single Mariposa
> > concentrating module in his 12 V system for maybe 15 years, and
> last I heard
> > it was doing fine.
> > http://solardyne.stores.yahoo.net/marconmod10k.html
> >
> > Clifford Krolick/ Back Country Excursions wrote at 06:36 PM
> 11/18/2009:
> >
> > >Michael
> > >
> > >All good points. I was hoping to not increase the heat coefficient
> > >with the reflection. I'm Not thinking about concentrating the light
> > >like a magnifying glass. Just thinking more in line that at a
> > >particular the distance away from the photo units there would be
> > >little or no thermal transfer just light transfer. But probably
> this
> > >is wishful thinking. What's your take?
> > >
> > >
> > >Cliff
> > >Parsonsfield, Maine, USA
> > >
> > >
> > >On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
> > >
> > >> 1. Adding reflectors will increase the temperature of the PV
> cells
> > >> which will decrease the output. It will also shorten the life
> of the
> > >> modules and probably void any warranty.
> > >>
> > >> 2. Tracking the sun is a good idea if either you have good
> horizon
> > >> to horizon exposure, or if you need to maximize available power
> > >> either early or late in the day, like in irrigation pumping
> > >> applications. Otherwise, you are probably better off with a fixed
> > >> array and spending the tracker money on more modules instead.
> > >>
> > >> BjornOlaf wrote at 02:02 PM 11/17/2009:
> > >>
> > >>> I am not so sure reflecting light onto the panels would be that
> > >>> effective unless you tracked the sun.... I did however read
> > >>> somewhere that tracking the sun with the panel gave about 40%
> more
> > >>> energy than simply having the panel stationary at the optimal
> noon
> > >>> position....
> > >>> Â
> > >>> Bjorn Justnes
> > >>> La Vinzelle
> > >>> France
> > >>>
> > >>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country
> Excursions <
> > bcountry@...
> > >>> > wrote:
> > >>>
> > >>>
> > >>> From: Clifford Krolick/ Back Country Excursions
> <bcountry@...>
> > >>> Subject: Re: [microhydro] Very small scale generators.
> > >>> To: microhydro@yahoogroups.com
> > >>> Date: Tuesday, November 17, 2009, 5:30 PM
> > >>>
> > >>>
> > >>> Â
> > >>>
> > >>>
> > >>>
> > >>> Jb
> > >>>
> > >>> Certainly for some of us we'll have to do a combination of
> things to
> > >>> create enough Electricity. Has any one heard of using reflective
> > >>> technology to significantly increase output of photoV panels??
> > >>> On Nov 16, 2009, at 6:56 PM, JB wrote:
> > >>
> > >>
> > >>
> >
>
> [Non-text portions of this message have been removed]
>
> Back to top
> Reply to sender | Reply to group | Reply via web post
> Messages in this topic (51)
> 3a.
> Re: Overspeed braking.
> Posted by: "Nento Luki" ironsand2004@...   ironsand2004
> Sun Nov 22, 2009 3:17 pm (PST)
>
>
>
> Thanks Nando
>
> What I mean the grid is a 2 X 25 MW Diesel Power
> Plant, that sometimes cut off without prior notice. Am I right that
> the
> turbine would dangerously overspeed??
>
> My hydro plant will be attended for 24 hours, but I want to have a
> saftey measure as human error may happen uexpectedly..
>
> The
> runner diameter is not fixed yet, but normally we design the
> peripherial speed  at about 48-48,5 % of water end velocity which is
> 33. 73  m/sec. The peripherial speed of the runner would be in the
> range 16 m/sec. The net length of the runner will depend on the nozzle
> maximum area, which is taken from volume of the design flow. The
> length of the Runner is also limitted by shaft size.
>
> .
> The creek has a minimu flow of  520 liters/sec during longest dry
> season in 2007.
> In 2008 its minimum  was 760 l/sec. Rain season in 2008 was 1,2 m3/sc.
> But
> the maximum allowable flow to be used for the  plant is 500 l/sec.
> provided there should be at least 75 l/sec to flow down the original
> creek (weir overflow) and or be diverted for other use. I have just an
> sms from the site that the maximum allowable flow has been incresed to
> 600 l/s.
>
> The owner also suggests tol have an independent 5 KW power for
> local lighting etc.My idea is to tap a  4" schedule 40  pipe from
> the penstock about 5 meters behind the Main Buterfly Valve. and use
> centrifugal pump fully controllede by ELC (air cooled heater). Do you
> have any other idea??.
>
>
> Anyway
> the plant is still at stage of making acces road to the weir point,
> laying out haed race. I still have enough time to discuss your idea
> with my designers. As I also think that I must not stick on Banki and
> horizontal generator.
>
> ThanksNando
> Best Regards
>
> --- On Sat, 11/21/09, Nando <nando37@...> wrote:
>
> From: Nando <nando37@...>
> Subject: Re: [microhydro] Re: Overspeed braking.
> To: microhydro@yahoogroups.com
> Cc: ironsand2004@...
> Date: Saturday, November 21, 2009, 7:28 PM
>
>
>
> Nento:
>
> You said:
>
> Flat belt transmission is of course the cheapest choice.
>
> The Cheapest choice could be, OF COURSE, the most expensive long
> term !!
>
> My way to analyze your site does not contemplate a Banki, and the
> reason is simple, now days the technology is quite better for NOT
> to use a Banki, even if you say it is cheaper to make in your
> country -- there are other ways to do this and use different
> turbine that may not require belts for RPM changes, though I expect
> that some in the group will contest my idea, but that is one of the
> ways to accomplish ideas expressed for you to decide or to make
> changes to your plan.
>
> The site seems good for 58 * 430 *6.5 = 162 KW -- though you are
> not defining the minimum and maximum flows to be able to see
> suggestions more adaptable to the site.
>
> Since the place have GRID drop-outs often, then the idea would be
> that the hydro to be able to run isolated during those times.
>
> One Turgo attached to a 250 HP motor will do since the GRID may
> bias it into a generator.
>
> If you need to have energy (isolated) when the GRID drops, USE an
> additional smaller generator, around 20 % that can be used to bias
> the large motor to have this way a simple hydro system isolated
> during those drop outs -- which you are not defined how long the
> duration is -- if drops due to weather, I presume several hours at
> least.
>
> If Turgo Interested, www.h-hydro. com and ask Joe about larger
> Spoons for such high power.
>
> Also, an alternative idea would be 2 each 80 KW hydro in parallel -
> maybe more accessible and easier to install and maintain and in all
> these cases NO belts no extra bearings.
>
> I will attach a photo of a 80 KW Turgo turbine with six Nozzles,
> electrically controlled, this designed and built by Peter Ruyter
> ( Sweden) and Sandro Fattore ( Italy).
>
> In this case you may need an ELC capable of controlling the full
> power and the difference, in this case, is the Semiconductors sizes
> and the ballast loads ( water cooled).
>
> For any type you may install, you may need to make sure that the
> full MECHANICAL power available at any moment is controllable with
> some means, when the GRID drops -- If you go with a Induction motor
> then the problem is a bit different because the GRID going way will
> remove the bias for the motor and not longer a load for the Turbine
> which will over speed to the speed of the water.
>
> For a Banki, sudden unload due to the large Nozzle throat area, may
> call for a TRUCK size brake with partial loading and electrical
> controlled valve to attain the 10 seconds to avoid the Ramming
> water problems.
>
> In a 12 inches long turbine the unloaded protection was done using
> the back of the throat nozzle to be opened to redirect the water
> away from the turbine, the plate was hinged and internally long to
> close the banki nozzle--
>
> Though Caveat Emptor since I just saw a photo and a short
> explanation of the protection.
>
> How did you defined the diameter of the Banki ?. and the length ?
>
> Nando
>
> ----- Original Message -----
>
> From: Nento Luki
>
> To: microhydro@yahoogro ups.com
>
> Sent: Friday, November 20, 2009 6:42 PM
>
> Subject: [microhydro] Re: Overspeed braking.
>
> --- On Fri, 11/20/09, Manfred Mornhinweg <manfred@ludens. cl> wrote:
>
> Dear Nando.
>
> I am about to work on a cross flow turbine for 58 meter Head and
> 430 liter per secod. 310 mm runner..The penstock is calculated to
> withstand water hammer at 10 second Valve closing time. I am
> planning to directly couple with 1000 RPM alternator.
>
> This will be grid connected which sometimes cuts off without notice
> causing a black out.
>
> This generator is not easily available in Indonesia. Then I have to
> go back to standard 4 pole alternator.
>
> Flat belt tramsission is of course the cheapest choice.
>
> Some suggest to install ELC dummy Load (about 50 KW??), to brake
> the alternator in case of a
>
> black out comes from the grid.. The others say to use a mechanical
> brake because the dummy load does not protect the turbine when the
> flat belt fails. But I think belt failure only occures on sudden
> increasing load not on the reverse.
>
> Any comment or other uggestions.
>
> Thanks
>
> Nento
>
> .
>
> I have been absent for almost two months from the group but it is
> ialso time consuming deleting the posting from those repeated basic
> questions. I come again because being interested with your opinion.
>
> It is not easy to gest which mail come from those in real micro
> hydro practical people such as the designer, the contractor,
> operator, students or lecturers or just come from those having a
> hobby.of reading.
>
> I would suggest that every new comers read some basic literatures
> in the files before asking questions.
>
> One benefit of this group is to bring out practical
>
> problems experienced in the site which can only be solved by those
> having the same expereince and solutions.
>
> From: Manfred Mornhinweg <manfred@ludens. cl>
>
> Subject: [microhydro] Intro message for newcomers
>
> To: microhydro@yahoogro ups.com
>
> Date: Friday, November 20, 2009, 9:47 AM
>
> Dear all, and specially Wim, Nando,
>
> in this group we frequently get posts from newcomers to microhydro,
> who
>
> don't know the very basics, and come here looking to learn them.
> That's
>
> normal, good and fine, but old time group members easily get upset by
>
> all those many posts from newcomers asking the same questions and
> doing
>
> the same mistakes (both technical and in netiquette). Like so many, I
>
> also prefer talking to people with a real name and knowing their
>
> location, rather than talk to anonymous ghosts, but on the other
> hand I
>
> can understand very well that many newcomers don't know this,
> specially
>
> because there are many other forums on the web which actively
> encourage
>
> anonymous posting and prefer people using an alias rather than their
>
> name! And it must be mighty shocking to any newcomer who signs up
> here,
>
> posts a few basic questions, and then gets shot dead by people
> demanding
>
> his name, location and precise measurements of his water resource,
>
> instead of giving useful advice!
>
> So, I would propose that we keep a sort of "welcome briefing"
> handy, and
>
> whenever a newcomer shows up and anonymously says he has a creek and
>
> thinks it might power his home, farm, town or perhaps much of his
>
> country, then either the group moderator or anyone else could post
> this
>
> briefing, as an introduction and basic help for new members.
>
> As for the contents of this briefing, I would propose the following:
>
> ----------
>
> Basics about the Microhydro group:
>
> We are a worldwide group of people who are connected in some way to
>
> small water turbines and everything around them. Many of us have built
>
> turbines or accessory equipment, others are using microhydro systems
>
> built by others, while many simply enjoy thinking, writing, reading
> and
>
> dreaming about this technology.
>
> We like addressing each other by our real names. Anonymous posting is
>
> not welcome. Also we like to know where in the world you are located,
>
> because that is very important for determining suitable technologies,
>
> applicable laws, and so on.
>
> We like to help newcomers to this technology, as much as we like
>
> discussing more advanced topics, but we don't like explaining the same
>
> basics again and again to every new member. So, here comes the second
>
> part of this briefing:
>
> Basics about microhydro:
>
> The power of water that moves downslope can easily be harvested, and
>
> either used directly, or (more commonly) converted into electricity.
>
> When considering any microhydro project, the VERY FIRST thing you have
>
> to do, is measuring the flow rate (amount of water per unit of time)
>
> that you can use, in different times of the year, and the head
> (altitude
>
> difference between the intake point and the turbine site). Then you
> can
>
> calculate how much power can be extracted, and then decide whether
>
> it's worth doing this.
>
> The power available is given by simple laws of physics: The head
>
> multiplied by the flow rate, multiplied by the gravitational constant,
>
> gives the gross power. Using metric units, no conversion constants of
>
> any sort are necessary, so that you can multiply the head in meters by
>
> the flow rate in liters per second, multiply this by the gravitational
>
> constant of 9.8, to obtain the gross power in watts. The use of
>
> nonstandard units, such as the English Imperial Units, is not
>
> recommended, because any calculation using these units requires the
> use
>
> of constants, which easily lead to mistakes when being mis-applied.
>
> The net electrical power you can obtain is always lower than the gross
>
> power. How much lower it is, depends on the losses of each part in the
>
> system: Filter, penstock, valves, nozzles, turbine, generator,
>
> transmission system, and possibly some more. An overall efficiency of
>
> 60% is achievable in a well designed system. Very small systems (less
>
> than 1000 watts) tend to be less efficient than this, while industrial
>
> scale systems are typically much more efficient than 60%.
>
> Since examples are always clearer than descriptions, here is an
> example:
>
> If you have a creek tumbling down a steep slope, and you can take
> in 10
>
> liters of water per second at a certain altitude, and return it to the
>
> creek at an altitude 50 meters lower, placing the turbine at that
> lower
>
> location, then the gross power you have available will be 10 * 50 *
> 9.8
>
> = 4900 watts, and if your system is well designed and built, you can
>
> harvest roughly 4900 * 0.6 = 2940 watts of electrical power.
>
> The head and flow rate MUST be measured, NOT estimated. Estimated
> values
>
> are completely useless, because even for professionals it's very
> hard to
>
> estimate these with any reasonable accuracy.
>
> Relatively long distances between the water intake and the turbine
> site
>
> are OK, if a low loss penstock is used. But such long distances
> sharply
>
> increase penstock cost. A large head in a small distance makes a
>
> microhydro system much more cost-effective.
>
> The required minimum penstock diameter is usually larger than what
>
> newcomers think. A good rule of thumb for an initial estimation of
>
> penstock diameter is that the flow velocity in the penstock should be
>
> roughly one meter per second. Basic geometry and math allows
> calculating
>
> the flow velocity for any given pipe diameter and flow rate. From this
>
> approximation, it might be convenient or even necessary to deviate a
>
> bit, according to the resulting penstock size, and its length.
>
> Generally, larger penstocks can work at slightly higher flow velocity,
>
> and long penstocks must be slightly larger than short ones.
>
> Large amounts of water flowing fast, but with almost no available
> head,
>
> such as in a large, deep, fast-flowing river, can produce some power,
>
> but these systems are generally more problematic than a microhydro
>
> turbine that uses a small amount of water with a large head.
>
> The turbine type is selected depending on the flow rate and head of
> the
>
> site, and interacts with the generator selection. The generator in
> very
>
> small systems might generate DC, charge batteries, and use either the
>
> low voltage directly, or convert it to standard line voltage AC in an
>
> inverter. Larger systems generate AC directly, making them much
> simpler,
>
> efficient and more cost-effective. In some cases, in can be convenient
>
> to connect your microhydro system to the public grid, but in most
> cases
>
> this is either not feasible, or not convenient. These decisions will
>
> come later, once you have gained complete clarity about your site's
>
> characteristics and power capability.
>
> Magical solutions do not exist. Damming up a creek does not
> increase the
>
> average flow rate. There is no turbine that can produce more
> mechanical
>
> power than the power available in your water source. There is no gear
>
> system that can multiply the power. And there is no generator that can
>
> produce more electrical power than the mechanical power put into
> it. And
>
> while a battery system can deliver a power much higher than the
> power of
>
> the turbine system, for a short time, it cannot increase the average
>
> power. In fact, each of these devices looses some energy!
>
> Don't spend any money or work on turbines, generators, penstocks,
> dams,
>
> batteries, etc, before you have designed the complete system, based on
>
> sound measurement of your water resource. If you rush to buy stuff,
> it's
>
> highly likely that you will buy the wrong parts for your site, wasting
>
> your money.
>
> Welcome to the group!
>
> ------------ --------- --------- --
>
> So, what do you think? What's missing? Should we let loose something
>
> like this on every newcomer?
>
> Manfred, from the slope of the Llaima volcano in southern Chile.
>
> This message was powered by microhydro.
>
> ============ ========= ===
>
> Visit my hobby homepage!
>
> http://ludens. cl
>
> ============ ========= ===
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
> [Non-text portions of this message have been removed]
>
> Back to top
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> Messages in this topic (4)
> 3b.
> Re: Overspeed braking.
> Posted by: "jrkess98@..." jrkess98@...   jkftl
> Sun Nov 22, 2009 9:56 pm (PST)
>
>
>
> Synchronous vs. isochronous
>
> If you are tied into the grid and making money on your plant, and
> the grid
> drops off, yes your unit will overspeed, but only to to the limit
> of the
> source. If, however, you have isochronous control with servos on
> the water
> source, or a big load bank, it won't care. Such controls are very
> costly.
> J. Kessler, Ft. Lauderdale
>
> [Non-text portions of this message have been removed]
>
> Back to top
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[Non-text portions of this message have been removed]

Michael

Yes I agree more light equals more heat but maybe as your friend has
done it is possible to add some reflective light up to a point.  Then
maybe a periodic monitoring of surface temps of the panels during full
sun exposure would lend more info.
I'd wonder if there might be other mitigating factors , possibly local
conditions effecting over heating.    Cliff

On Nov 22, 2009, at 2:27 PM, Michael Welch wrote:

> I do not see how you can practically increase one without the other.
> Just adding more light to the same area of PV cells will also
> increase the heat.
>
> Early in commercial PV history, a rather large utility PV array
> added stainless steel reflective wings on each side of some standard
> modules. Failure rates were higher than expected, and the modules
> started discoloring. The industry learned never to do that again.
>
> On the other hand, I have a friend that has had a single Mariposa
> concentrating module in his 12 V system for maybe 15 years, and last
> I heard it was doing fine.
> http://solardyne.stores.yahoo.net/marconmod10k.html
>
> Clifford Krolick/ Back Country Excursions wrote at 06:36 PM
> 11/18/2009:
>
>> Michael
>>
>> All good points.  I was hoping to not increase the heat coefficient
>> with the reflection.  I'm Not thinking about concentrating the light
>> like a magnifying glass.  Just thinking more in line that at a
>> particular the distance away from the photo units there would be
>> little or no thermal transfer just light transfer. But  probably this
>> is wishful thinking.  What's your take?
>>
>>
>> Cliff
>> Parsonsfield, Maine, USA
>>
>>
>> On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
>>
>>> 1. Adding reflectors will increase the temperature of the PV cells
>>> which will decrease the output. It will also shorten the life of the
>>> modules and probably void any warranty.
>>>
>>> 2. Tracking the sun is a good idea if either you have good horizon
>>> to horizon exposure, or if you need to maximize available power
>>> either early or late in the day, like in irrigation pumping
>>> applications. Otherwise, you are probably better off with a fixed
>>> array and spending the tracker money on more modules instead.
>>>
>>> BjornOlaf wrote at 02:02 PM 11/17/2009:
>>>
>>>> I am not so sure reflecting light onto the panels would be that
>>>> effective unless you tracked the sun.... I did however read
>>>> somewhere that tracking the sun with the panel gave about 40% more
>>>> energy than simply having the panel stationary at the optimal noon
>>>> position....
>>>> Â
>>>> Bjorn Justnes
>>>> La Vinzelle
>>>> France
>>>>
>>>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions
<bcountry@...
>>>>> wrote:
>>>>
>>>>
>>>> From: Clifford Krolick/ Back Country Excursions <bcountry@...
>>>> >
>>>> Subject: Re: [microhydro] Very small scale generators.
>>>> To: microhydro@yahoogroups.com
>>>> Date: Tuesday, November 17, 2009, 5:30 PM
>>>>
>>>>
>>>> Â
>>>>
>>>>
>>>>
>>>> Jb
>>>>
>>>> Certainly for some of us we'll have to do a combination of things
>>>> to
>>>> create enough Electricity. Has any one heard of using reflective
>>>> technology to significantly increase output of photoV panels??
>>>> On Nov 16, 2009, at 6:56 PM, JB wrote:
>>>
>>>
>>>
>>> ------------------------------------
>>>
>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>> ? If not, please register free of charge and be exposed to the
>>> microhydro community world wide!
>>>
>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>> provides us with free email group services. The microhydro-group
>>> does not endorse products or support the advertisements in any way.
>>>
>>> More information on micro hydropower at http://microhydropower.net
>>>
>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>>> ! Groups Links
>>>
>>>
>>>
>>
>>
>>
>> ------------------------------------
>>
>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>  ? If not, please register free of charge and be exposed to the
>> microhydro community world wide!
>>
>> NOTE: The advertisements in this email are added by Yahoogroups who
>> provides us with free email group services. The microhydro-group
>> does not endorse products or support the advertisements in any way.
>>
>> More information on micro hydropower at http://microhydropower.net
>>
>> To unsubscribe: send empty message to
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>>
>>
>>
>
>
> ------------------------------------
>
> Does your company feature in the microhydro business directory at
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>  ? If not, please register free of charge and be exposed to the
> microhydro community world wide!
>
> NOTE: The advertisements in this email are added by Yahoogroups who
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> does not endorse products or support the advertisements in any way.
>
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>
> To unsubscribe: send empty message to
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> ! Groups Links
>
>
>

Wrote to the group once and enjoy reading about members experiences.
Manfred, very well explained. Thank you.

among new members,
Bozidar, Serbia


[Non-text portions of this message have been removed]

Hi Nento,

  > Am I right that the turbine would dangerously overspeed??

If suddenly the load is disconnected, indeed your turbine will
overspeed. Whether or not this is dangerous, depends on how it is built.
Turbines and generators can be made to withstand such overspeed without
damage, but this is more costly than making machines that don't need to
survive overspeeding.

There are many cases in which the turbine can survive such overspeeding,
but the generator cannot.

Sudden load disconnections WILL eventually happen, so you MUST plan for
them, either by using machinery designed to survive the runaway speed,
or by having the necessary emergency brakes. And very likely the best
method for implementing such an emergency brake for the whole machine is
a big dump load with some sort of ELC, which actually can be quite
crude, because its only purpose is to keep the speed in a safe range in
the event of an emergency. Of course, such an electrical brake will NOT
protect the turbine, if you use belt transmission and the belt fails. If
at all possible, use direct drive from the turbine to the generator,
which is safer, cheaper, more compact, more efficient, and generally
less problematic.

I have seen large commercial hydro plants with a big box of load
resistors in their backyard! One time I got a chance to ask an employee
there about these resistors. He told me they were the emergency dump
load. If for any reason the plant was suddenly disconnected from the
grid, an automatic controller would instantly switch in the load
resistors to keep the machines from overspeeding, and also initiate a
safe shutdown, closing the water valves at their normal speed, low
enough to avoid waterhammer. The resistors were not large enough to take
the full plant output continuously, but enough to take the output for
the short time it takes to close the valves.

I think that's the way to go in a relatively large plant. In a small
one, it's more cost-effective to have enough dump loads to dissipate the
whole plant output continuously, and avoid the need to have any
automatically controlled water valves.

Manfred.


========================
Visit my hobby homepage!
http://ludens.cl
========================

Hi all,

In naca-report-460.pdf where I could find the deviation angle of an
airfoil please ?

j.
Le 8 nov. 09 à 00:33, Tony N a écrit :

> O'Brien & Folsom wrote a paper on foils in fluid, in 1939.
> Tony N
>
> --- In microhydro@yahoogroups.com, "Joel" <joel@...> wrote:
> >
> > Marko
> > You are probably right about Nechleba and Vesiturbiinit. I guess I
> got the idea Flaspohler based his work on Nechleba as I saw some
> diagrams in Nechleba's book that seems identical to Flaspohler
> theses. Maybe Nechleba based some of his work on Ahlfors K Axel's
> book Vestturbii as it was written earlier.
> > Thanks for the offer of part of nechleba's book but I have access
> to it already.
> > Joel
> >
> > ----- Original Message -----
> > From: acme11_hydro
> > To: microhydro@yahoogroups.com
> > Sent: Monday, October 26, 2009 1:18 PM
> > Subject: [microhydro] Re: kaplan
> >
> >
> > Hi Joel
> >
> > I didn'find Nechleba in his references. He use book
> "Vesiturbiinit" (Ahlfors, K. Axel. Helsinki, Finland: Porvoo, 1932),
> and gottingen (goe)airfoils. I didn't find any data on this
> airfoils. I think, if you will stay on Timo's work you will need
> that book.
> >
> > If you want, I will send you a part of Nechleba work.
> >
> > Marko
> >
> > --- In microhydro@yahoogroups.com, "Joel" <joel@> wrote:
> > >
> > > Hi Marko,
> > > I put together a spreadsheet on Flaspohler's theses as well and
> it seemed to pretty much match his figures but I kept coming up with
> things that didn't seem right. I thought it was my math skills and
> that may still be the case. I actually found your spreadsheet on a
> link from French river land and posted it here. From what I could
> tell it seemed Flaspohler's math was based on Nechleba's work. At
> the moment I don't have the time to break the math down.
> >
> >
> >
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>

--------------------------------------------------

Jerome Dubois
dubois@...
duboisjeromejulien@...

Institut de Mathematiques de Jussieu
Université Paris Diderot-Paris 7
UFR de Mathématiques
Case 7012 Bâtiment Chevaleret
75205 PARIS CEDEX 13

phone: (+33)(0)1 44 27 54 40

page web : http://people.math.jussieu.fr/~dubois/
--------------------------------------------------








[Non-text portions of this message have been removed]

There was a photo in Home Power magazine showing that, I believe. The light was
reflected to strike the ceiling of the room being lit.

Sometimes, things are done just to do it.

Frank

________________________________
From: microhydro@yahoogroups.com [mailto:microhydro@yahoogroups.com] On Behalf
Of William Wixon
Sent: Sunday, November 22, 2009 7:54 PM
To: microhydro@yahoogroups.com
Subject: Re: [microhydro] Very small scale generators.



sorry to be diverging from the microhydro topic but this discussion about
reflecting sunlight touched on something i had wondered just the other day,
and had wondered about in the past as well, i'm sure there must be a
downside or it would already be being done, but i wondered why don't people
put mirrors on a tracking device and just reflect straight sunlight into the
windows of their home for supplimental heat and light (for example, on the
northern side of their homes)? im guessing havnig blinding sunlight coming
in your windows at a low angle would be very distracting and uncomfortable,
and probably it wouldnt make economic sense to have an expensive tracker for
the availble BTU's of reflected sunlight.... etc.
just wondering.
has it already been done? would it even be possible to track and aim
sunlight into a window?

On Sun, Nov 22, 2009 at 1:27 PM, Michael Welch
<michael_welch@...<mailto:michael_welch%40sbcglobal.net>>wrote:

> I do not see how you can practically increase one without the other. Just
> adding more light to the same area of PV cells will also increase the heat.
>
> Early in commercial PV history, a rather large utility PV array added
> stainless steel reflective wings on each side of some standard modules.
> Failure rates were higher than expected, and the modules started
> discoloring. The industry learned never to do that again.
>
> On the other hand, I have a friend that has had a single Mariposa
> concentrating module in his 12 V system for maybe 15 years, and last I heard
> it was doing fine.
> http://solardyne.stores.yahoo.net/marconmod10k.html
>
> Clifford Krolick/ Back Country Excursions wrote at 06:36 PM 11/18/2009:
>
> >Michael
> >
> >All good points. I was hoping to not increase the heat coefficient
> >with the reflection. I'm Not thinking about concentrating the light
> >like a magnifying glass. Just thinking more in line that at a
> >particular the distance away from the photo units there would be
> >little or no thermal transfer just light transfer. But probably this
> >is wishful thinking. What's your take?
> >
> >
> >Cliff
> >Parsonsfield, Maine, USA
> >
> >
> >On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
> >
> >> 1. Adding reflectors will increase the temperature of the PV cells
> >> which will decrease the output. It will also shorten the life of the
> >> modules and probably void any warranty.
> >>
> >> 2. Tracking the sun is a good idea if either you have good horizon
> >> to horizon exposure, or if you need to maximize available power
> >> either early or late in the day, like in irrigation pumping
> >> applications. Otherwise, you are probably better off with a fixed
> >> array and spending the tracker money on more modules instead.
> >>
> >> BjornOlaf wrote at 02:02 PM 11/17/2009:
> >>
> >>> I am not so sure reflecting light onto the panels would be that
> >>> effective unless you tracked the sun.... I did however read
> >>> somewhere that tracking the sun with the panel gave about 40% more
> >>> energy than simply having the panel stationary at the optimal noon
> >>> position....
> >>> Â
> >>> Bjorn Justnes
> >>> La Vinzelle
> >>> France
> >>>
> >>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions <
> bcountry@...<mailto:bcountry%40psouth.net>
> >>> > wrote:
> >>>
> >>>
> >>> From: Clifford Krolick/ Back Country Excursions
<bcountry@...<mailto:bcountry%40psouth.net>>
> >>> Subject: Re: [microhydro] Very small scale generators.
> >>> To: microhydro@yahoogroups.com<mailto:microhydro%40yahoogroups.com>
> >>> Date: Tuesday, November 17, 2009, 5:30 PM
> >>>
> >>>
> >>> Â
> >>>
> >>>
> >>>
> >>> Jb
> >>>
> >>> Certainly for some of us we'll have to do a combination of things to
> >>> create enough Electricity. Has any one heard of using reflective
> >>> technology to significantly increase output of photoV panels??
> >>> On Nov 16, 2009, at 6:56 PM, JB wrote:
> >>
> >>
> >>
>

[Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

For the most part, all of us are net-friends, even though we haven't ever met.

Frank

________________________________
From: microhydro@yahoogroups.com [mailto:microhydro@yahoogroups.com] On Behalf
Of Manfred Mornhinweg
Sent: Sunday, November 22, 2009 10:38 AM
To: microhydro@yahoogroups.com
Subject: [microhydro] Re: Intro message for newcomers



Hi John,

> Can you explain how to measure the flow accurately?

For small creeks, probably the best method is capturing the entire creek
with a provisional intake made from a pipe buried in an earthen dam, and
use a stopwatch and a container of known capacity to measure how long it
takes to fill, and do the math.

For larger creeks, probably the best method is making a provisional weir
from a plank, sealed with earth, plastic, stones, whatever, and cut a 90
degree V-shaped notch in it. Then install a stick in the little pond
that forms behind that weir, with a ruler attached to it, so that it
shows water heigth above the low corner of the notch. A simple formula
relates the flow rate to the water height above that corner of the notch:

Flow = 1.36 * height^2.5

This is in basic units of the international system, which is, height in
meters and flow in cubic meters per second.

This system is quite precise for a relatively wide range of flows.

And if the flow is more than what can be handled with such a V-shaped
notch, then leave the plank uncut, so that water overflows it on its
entire length. Install the ruler so that it measure water height above
the plank, and use this formula:

Flow = 1.7 * length * height^1.5

This is less accurate than the other one, but good enough if the plank
is long enough so that the length is many times the water height over
it. This equation is also in basic units (meters, cubic meters).

The water level ruler must be installed far enough back from the weir so
that it is at a place where the water is not yet going downslope over
the weir.

With one of these three methods, any water resource apt for microhydro
can be measured.

And for Don:

I understand concerns about privacy and identity theft, even if I don't
think this is so critical. My position is somewhat fatalistic: The
really bad guys know everything about me and you, so we are exposed to
their misdoings, no matter what we do!

But to anyone concerned with privacy to the point of not wanting to tell
his real name, I would dare to suggest to make up a name, but one that
sounds real, and stick to it. We will then all know that person by that
invented name. He will be Jack Smith to us, even if his real name might
be John Miller. So what, and his real identity stays protected. But if
he chooses Turbojack as an alias, it will be obvious that that isn't
his real name, and so some of us will feel like talking to a ghost! And
if he chooses several aliases and switches them all the time, this will
confuse us. The location should be correct, though, even if it certainly
doesn't need to be as detailed as a street address. I suppose that if
someone tells us he lives in the foothills of the Drakensberg range in
South Africa, that's precise enough. It allows to place him, and
possibly to give location-specific advice. It's very different than if
that person were located near Bern, Switzerland, for example. The
resources available, the laws, ease to get technological solutions,
availability of a power grid, and so on, and even the style of doing
things, are likely to be very different.

I personally have often written to "ghosts", as Nando likes to call
anonymous posters, and I don't feel so bad about that as he does, but
really it makes things easier and nicer when one can place the person!

Manfred.

========================
Visit my hobby homepage!
http://ludens.cl
========================




[Non-text portions of this message have been removed]

Hi Cliff. Yes, you can do that. But 1) it probably is not worth it, PV modules
are cheap now and 2) it will likely void your warranty.

Everyone wants to try something different than is being done now. But people and
companies have been experimenting with this stuff for 50 years, and have settled
into a pretty good groove about what works and what doesn't, and what is or is
not worthwhile.

While there are still some things new to be invented and tried, this is not one
of them.

Clifford Krolick/ Back Country Excursions wrote at 05:00 AM 11/23/2009:

>Michael
>
>Yes I agree more light equals more heat but maybe as your friend has
>done it is possible to add some reflective light up to a point.  Then
>maybe a periodic monitoring of surface temps of the panels during full
>sun exposure would lend more info.
>I'd wonder if there might be other mitigating factors , possibly local
>conditions effecting over heating.    Cliff
>
>On Nov 22, 2009, at 2:27 PM, Michael Welch wrote:
>
>> I do not see how you can practically increase one without the other.
>> Just adding more light to the same area of PV cells will also
>> increase the heat.
>>
>> Early in commercial PV history, a rather large utility PV array
>> added stainless steel reflective wings on each side of some standard
>> modules. Failure rates were higher than expected, and the modules
>> started discoloring. The industry learned never to do that again.
>>
>> On the other hand, I have a friend that has had a single Mariposa
>> concentrating module in his 12 V system for maybe 15 years, and last
>> I heard it was doing fine.
>> http://solardyne.stores.yahoo.net/marconmod10k.html
>>
>> Clifford Krolick/ Back Country Excursions wrote at 06:36 PM
>> 11/18/2009:
>>
>>> Michael
>>>
>>> All good points.  I was hoping to not increase the heat coefficient
>>> with the reflection.  I'm Not thinking about concentrating the light
>>> like a magnifying glass.  Just thinking more in line that at a
>>> particular the distance away from the photo units there would be
>>> little or no thermal transfer just light transfer. But  probably this
>>> is wishful thinking.  What's your take?
>>>
>>>
>>> Cliff
>>> Parsonsfield, Maine, USA
>>>
>>>
>>> On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
>>>
>>>> 1. Adding reflectors will increase the temperature of the PV cells
>>>> which will decrease the output. It will also shorten the life of the
>>>> modules and probably void any warranty.
>>>>
>>>> 2. Tracking the sun is a good idea if either you have good horizon
>>>> to horizon exposure, or if you need to maximize available power
>>>> either early or late in the day, like in irrigation pumping
>>>> applications. Otherwise, you are probably better off with a fixed
>>>> array and spending the tracker money on more modules instead.
>>>>
>>>> BjornOlaf wrote at 02:02 PM 11/17/2009:
>>>>
>>>>> I am not so sure reflecting light onto the panels would be that
>>>>> effective unless you tracked the sun.... I did however read
>>>>> somewhere that tracking the sun with the panel gave about 40% more
>>>>> energy than simply having the panel stationary at the optimal noon
>>>>> position....
>>>>> Â
>>>>> Bjorn Justnes
>>>>> La Vinzelle
>>>>> France
>>>>>
>>>>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions
<bcountry@...
>>>>>> wrote:
>>>>>
>>>>>
>>>>> From: Clifford Krolick/ Back Country Excursions <bcountry@...
>>>>> >
>>>>> Subject: Re: [microhydro] Very small scale generators.
>>>>> To: microhydro@yahoogroups.com
>>>>> Date: Tuesday, November 17, 2009, 5:30 PM
>>>>>
>>>>>
>>>>> Â
>>>>>
>>>>>
>>>>>
>>>>> Jb
>>>>>
>>>>> Certainly for some of us we'll have to do a combination of things
>>>>> to
>>>>> create enough Electricity. Has any one heard of using reflective
>>>>> technology to significantly increase output of photoV panels??
>>>>> On Nov 16, 2009, at 6:56 PM, JB wrote:
>>>>
>>>>
>>>>
>>>> ------------------------------------
>>>>
>>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>>> ? If not, please register free of charge and be exposed to the
>>>> microhydro community world wide!
>>>>
>>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>>> provides us with free email group services. The microhydro-group
>>>> does not endorse products or support the advertisements in any way.
>>>>
>>>> More information on micro hydropower at http://microhydropower.net
>>>>
>>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>>>> ! Groups Links
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> ------------------------------------
>>>
>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>>  ? If not, please register free of charge and be exposed to the
>>> microhydro community world wide!
>>>
>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>> provides us with free email group services. The microhydro-group
>>> does not endorse products or support the advertisements in any way.
>>>
>>> More information on micro hydropower at http://microhydropower.net
>>>
>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>>> ! Groups Links
>>>
>>>
>>>
>>
>>
>> ------------------------------------
>>
>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>  ? If not, please register free of charge and be exposed to the
>> microhydro community world wide!
>>
>> NOTE: The advertisements in this email are added by Yahoogroups who
>> provides us with free email group services. The microhydro-group
>> does not endorse products or support the advertisements in any way.
>>
>> More information on micro hydropower at http://microhydropower.net
>>
>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>> ! Groups Links
>>
>>
>>
>
>
>
>------------------------------------
>
>Does your company feature in the microhydro business directory at
http://microhydropower.net/directory ? If not, please register free of charge
and be exposed to the microhydro community world wide!
>
>NOTE: The advertisements in this email are added by Yahoogroups who provides us
with free email group services. The microhydro-group does not endorse products
or support the advertisements in any way.
>
>More information on micro hydropower at http://microhydropower.net
>
>To unsubscribe: send empty message to
microhydro-unsubscribe@...! Groups Links
>
>
>

Howdy...........there is  a tiny company in Massachusetts that makes trackers
soley for the purpose of reflecting lite into north facing windows........the
trackers are comtrolled by a tiny chip that runs two tiny servo motors and once
the mirrors are oriented correctly the chip is programmed to reflect the sun to
any location without the use of sun position sensors.......pretty nifty......i
think each tracker can hold 32 sq ft of mirrors and uses an average of two
watts.............mark in Orford,NH
   ----- Original Message -----
   From: Frank Leslie
   To: microhydro@yahoogroups.com
   Sent: Monday, November 23, 2009 1:15 PM
   Subject: RE: [microhydro] Very small scale generators.



   There was a photo in Home Power magazine showing that, I believe. The light
was reflected to strike the ceiling of the room being lit.

   Sometimes, things are done just to do it.

   Frank

   ________________________________
   From: microhydro@yahoogroups.com [mailto:microhydro@yahoogroups.com] On Behalf
Of William Wixon
   Sent: Sunday, November 22, 2009 7:54 PM
   To: microhydro@yahoogroups.com
   Subject: Re: [microhydro] Very small scale generators.

   sorry to be diverging from the microhydro topic but this discussion about
   reflecting sunlight touched on something i had wondered just the other day,
   and had wondered about in the past as well, i'm sure there must be a
   downside or it would already be being done, but i wondered why don't people
   put mirrors on a tracking device and just reflect straight sunlight into the
   windows of their home for supplimental heat and light (for example, on the
   northern side of their homes)? im guessing havnig blinding sunlight coming
   in your windows at a low angle would be very distracting and uncomfortable,
   and probably it wouldnt make economic sense to have an expensive tracker for
   the availble BTU's of reflected sunlight.... etc.
   just wondering.
   has it already been done? would it even be possible to track and aim
   sunlight into a window?

   On Sun, Nov 22, 2009 at 1:27 PM, Michael Welch
   <michael_welch@...<mailto:michael_welch%40sbcglobal.net>>wrote:

   > I do not see how you can practically increase one without the other. Just
   > adding more light to the same area of PV cells will also increase the heat.
   >
   > Early in commercial PV history, a rather large utility PV array added
   > stainless steel reflective wings on each side of some standard modules.
   > Failure rates were higher than expected, and the modules started
   > discoloring. The industry learned never to do that again.
   >
   > On the other hand, I have a friend that has had a single Mariposa
   > concentrating module in his 12 V system for maybe 15 years, and last I heard
   > it was doing fine.
   > http://solardyne.stores.yahoo.net/marconmod10k.html
   >
   > Clifford Krolick/ Back Country Excursions wrote at 06:36 PM 11/18/2009:
   >
   > >Michael
   > >
   > >All good points. I was hoping to not increase the heat coefficient
   > >with the reflection. I'm Not thinking about concentrating the light
   > >like a magnifying glass. Just thinking more in line that at a
   > >particular the distance away from the photo units there would be
   > >little or no thermal transfer just light transfer. But probably this
   > >is wishful thinking. What's your take?
   > >
   > >
   > >Cliff
   > >Parsonsfield, Maine, USA
   > >
   > >
   > >On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
   > >
   > >> 1. Adding reflectors will increase the temperature of the PV cells
   > >> which will decrease the output. It will also shorten the life of the
   > >> modules and probably void any warranty.
   > >>
   > >> 2. Tracking the sun is a good idea if either you have good horizon
   > >> to horizon exposure, or if you need to maximize available power
   > >> either early or late in the day, like in irrigation pumping
   > >> applications. Otherwise, you are probably better off with a fixed
   > >> array and spending the tracker money on more modules instead.
   > >>
   > >> BjornOlaf wrote at 02:02 PM 11/17/2009:
   > >>
   > >>> I am not so sure reflecting light onto the panels would be that
   > >>> effective unless you tracked the sun.... I did however read
   > >>> somewhere that tracking the sun with the panel gave about 40% more
   > >>> energy than simply having the panel stationary at the optimal noon
   > >>> position....
   > >>> Â
   > >>> Bjorn Justnes
   > >>> La Vinzelle
   > >>> France
   > >>>
   > >>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions <
   > bcountry@...<mailto:bcountry%40psouth.net>
   > >>> > wrote:
   > >>>
   > >>>
   > >>> From: Clifford Krolick/ Back Country Excursions
<bcountry@...<mailto:bcountry%40psouth.net>>
   > >>> Subject: Re: [microhydro] Very small scale generators.
   > >>> To: microhydro@yahoogroups.com<mailto:microhydro%40yahoogroups.com>
   > >>> Date: Tuesday, November 17, 2009, 5:30 PM
   > >>>
   > >>>
   > >>> Â
   > >>>
   > >>>
   > >>>
   > >>> Jb
   > >>>
   > >>> Certainly for some of us we'll have to do a combination of things to
   > >>> create enough Electricity. Has any one heard of using reflective
   > >>> technology to significantly increase output of photoV panels??
   > >>> On Nov 16, 2009, at 6:56 PM, JB wrote:
   > >>
   > >>
   > >>
   >

   [Non-text portions of this message have been removed]

   [Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

Here in Florida, we have to worry about hurricanes and a 130 mph wind code. The
Ausra solar thermal project here was dropped when they realized that the
parabolic mirror arrays would have to be incredibly strong to meet code.

Frank

________________________________
From: microhydro@yahoogroups.com [mailto:microhydro@yahoogroups.com] On Behalf
Of Michael Welch
Sent: Monday, November 23, 2009 1:38 PM
To: microhydro@yahoogroups.com
Subject: Re: [microhydro] Very small scale generators.



Hi Cliff. Yes, you can do that. But 1) it probably is not worth it, PV modules
are cheap now and 2) it will likely void your warranty.

Everyone wants to try something different than is being done now. But people and
companies have been experimenting with this stuff for 50 years, and have settled
into a pretty good groove about what works and what doesn't, and what is or is
not worthwhile.

While there are still some things new to be invented and tried, this is not one
of them.

Clifford Krolick/ Back Country Excursions wrote at 05:00 AM 11/23/2009:

>Michael
>
>Yes I agree more light equals more heat but maybe as your friend has
>done it is possible to add some reflective light up to a point. Then
>maybe a periodic monitoring of surface temps of the panels during full
>sun exposure would lend more info.
>I'd wonder if there might be other mitigating factors , possibly local
>conditions effecting over heating. Cliff
>
>On Nov 22, 2009, at 2:27 PM, Michael Welch wrote:
>
>> I do not see how you can practically increase one without the other.
>> Just adding more light to the same area of PV cells will also
>> increase the heat.
>>
>> Early in commercial PV history, a rather large utility PV array
>> added stainless steel reflective wings on each side of some standard
>> modules. Failure rates were higher than expected, and the modules
>> started discoloring. The industry learned never to do that again.
>>
>> On the other hand, I have a friend that has had a single Mariposa
>> concentrating module in his 12 V system for maybe 15 years, and last
>> I heard it was doing fine.
>> http://solardyne.stores.yahoo.net/marconmod10k.html
>>
>> Clifford Krolick/ Back Country Excursions wrote at 06:36 PM
>> 11/18/2009:
>>
>>> Michael
>>>
>>> All good points. I was hoping to not increase the heat coefficient
>>> with the reflection. I'm Not thinking about concentrating the light
>>> like a magnifying glass. Just thinking more in line that at a
>>> particular the distance away from the photo units there would be
>>> little or no thermal transfer just light transfer. But probably this
>>> is wishful thinking. What's your take?
>>>
>>>
>>> Cliff
>>> Parsonsfield, Maine, USA
>>>
>>>
>>> On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
>>>
>>>> 1. Adding reflectors will increase the temperature of the PV cells
>>>> which will decrease the output. It will also shorten the life of the
>>>> modules and probably void any warranty.
>>>>
>>>> 2. Tracking the sun is a good idea if either you have good horizon
>>>> to horizon exposure, or if you need to maximize available power
>>>> either early or late in the day, like in irrigation pumping
>>>> applications. Otherwise, you are probably better off with a fixed
>>>> array and spending the tracker money on more modules instead.
>>>>
>>>> BjornOlaf wrote at 02:02 PM 11/17/2009:
>>>>
>>>>> I am not so sure reflecting light onto the panels would be that
>>>>> effective unless you tracked the sun.... I did however read
>>>>> somewhere that tracking the sun with the panel gave about 40% more
>>>>> energy than simply having the panel stationary at the optimal noon
>>>>> position....
>>>>> Â
>>>>> Bjorn Justnes
>>>>> La Vinzelle
>>>>> France
>>>>>
>>>>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions
<bcountry@...<mailto:bcountry%40psouth.net>
>>>>>> wrote:
>>>>>
>>>>>
>>>>> From: Clifford Krolick/ Back Country Excursions
<bcountry@...<mailto:bcountry%40psouth.net>
>>>>> >
>>>>> Subject: Re: [microhydro] Very small scale generators.
>>>>> To: microhydro@yahoogroups.com<mailto:microhydro%40yahoogroups.com>
>>>>> Date: Tuesday, November 17, 2009, 5:30 PM
>>>>>
>>>>>
>>>>> Â
>>>>>
>>>>>
>>>>>
>>>>> Jb
>>>>>
>>>>> Certainly for some of us we'll have to do a combination of things
>>>>> to
>>>>> create enough Electricity. Has any one heard of using reflective
>>>>> technology to significantly increase output of photoV panels??
>>>>> On Nov 16, 2009, at 6:56 PM, JB wrote:
>>>>
>>>>
>>>>
>>>> ------------------------------------
>>>>
>>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>>> ? If not, please register free of charge and be exposed to the
>>>> microhydro community world wide!
>>>>
>>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>>> provides us with free email group services. The microhydro-group
>>>> does not endorse products or support the advertisements in any way.
>>>>
>>>> More information on micro hydropower at http://microhydropower.net
>>>>
>>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...<mailto:microhydro-unsubscribe%40Yaho\
oGroups.comYahoo>
>>>> ! Groups Links
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>> ------------------------------------
>>>
>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>> ? If not, please register free of charge and be exposed to the
>>> microhydro community world wide!
>>>
>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>> provides us with free email group services. The microhydro-group
>>> does not endorse products or support the advertisements in any way.
>>>
>>> More information on micro hydropower at http://microhydropower.net
>>>
>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...<mailto:microhydro-unsubscribe%40Yaho\
oGroups.comYahoo>
>>> ! Groups Links
>>>
>>>
>>>
>>
>>
>> ------------------------------------
>>
>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>> ? If not, please register free of charge and be exposed to the
>> microhydro community world wide!
>>
>> NOTE: The advertisements in this email are added by Yahoogroups who
>> provides us with free email group services. The microhydro-group
>> does not endorse products or support the advertisements in any way.
>>
>> More information on micro hydropower at http://microhydropower.net
>>
>> To unsubscribe: send empty message to
microhydro-unsubscribe@...<mailto:microhydro-unsubscribe%40Yaho\
oGroups.comYahoo>
>> ! Groups Links
>>
>>
>>
>
>
>
>------------------------------------
>
>Does your company feature in the microhydro business directory at
http://microhydropower.net/directory ? If not, please register free of charge
and be exposed to the microhydro community world wide!
>
>NOTE: The advertisements in this email are added by Yahoogroups who provides us
with free email group services. The microhydro-group does not endorse products
or support the advertisements in any way.
>
>More information on micro hydropower at http://microhydropower.net
>
>To unsubscribe: send empty message to
microhydro-unsubscribe@...<mailto:microhydro-unsubscribe%40Yaho\
oGroups.comYahoo>! Groups Links
>
>
>




[Non-text portions of this message have been removed]

Michael

Sounds about right to me especially with the cost of panels so low.
Any suggestions on what  BRAND OR company I might get my best deal and
quality if I were to purchase very soon?

Much Thanks

Cliff
On Nov 23, 2009, at 1:37 PM, Michael Welch wrote:

> Hi Cliff. Yes, you can do that. But 1) it probably is not worth it,
> PV modules are cheap now and 2) it will likely void your warranty.
>
> Everyone wants to try something different than is being done now.
> But people and companies have been experimenting with this stuff for
> 50 years, and have settled into a pretty good groove about what
> works and what doesn't, and what is or is not worthwhile.
>
> While there are still some things new to be invented and tried, this
> is not one of them.
>
> Clifford Krolick/ Back Country Excursions wrote at 05:00 AM
> 11/23/2009:
>
>> Michael
>>
>> Yes I agree more light equals more heat but maybe as your friend has
>> done it is possible to add some reflective light up to a point.  Then
>> maybe a periodic monitoring of surface temps of the panels during
>> full
>> sun exposure would lend more info.
>> I'd wonder if there might be other mitigating factors , possibly
>> local
>> conditions effecting over heating.    Cliff
>>
>> On Nov 22, 2009, at 2:27 PM, Michael Welch wrote:
>>
>>> I do not see how you can practically increase one without the other.
>>> Just adding more light to the same area of PV cells will also
>>> increase the heat.
>>>
>>> Early in commercial PV history, a rather large utility PV array
>>> added stainless steel reflective wings on each side of some standard
>>> modules. Failure rates were higher than expected, and the modules
>>> started discoloring. The industry learned never to do that again.
>>>
>>> On the other hand, I have a friend that has had a single Mariposa
>>> concentrating module in his 12 V system for maybe 15 years, and last
>>> I heard it was doing fine.
>>> http://solardyne.stores.yahoo.net/marconmod10k.html
>>>
>>> Clifford Krolick/ Back Country Excursions wrote at 06:36 PM
>>> 11/18/2009:
>>>
>>>> Michael
>>>>
>>>> All good points.  I was hoping to not increase the heat coefficient
>>>> with the reflection.  I'm Not thinking about concentrating the
>>>> light
>>>> like a magnifying glass.  Just thinking more in line that at a
>>>> particular the distance away from the photo units there would be
>>>> little or no thermal transfer just light transfer. But  probably
>>>> this
>>>> is wishful thinking.  What's your take?
>>>>
>>>>
>>>> Cliff
>>>> Parsonsfield, Maine, USA
>>>>
>>>>
>>>> On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
>>>>
>>>>> 1. Adding reflectors will increase the temperature of the PV cells
>>>>> which will decrease the output. It will also shorten the life of
>>>>> the
>>>>> modules and probably void any warranty.
>>>>>
>>>>> 2. Tracking the sun is a good idea if either you have good horizon
>>>>> to horizon exposure, or if you need to maximize available power
>>>>> either early or late in the day, like in irrigation pumping
>>>>> applications. Otherwise, you are probably better off with a fixed
>>>>> array and spending the tracker money on more modules instead.
>>>>>
>>>>> BjornOlaf wrote at 02:02 PM 11/17/2009:
>>>>>
>>>>>> I am not so sure reflecting light onto the panels would be that
>>>>>> effective unless you tracked the sun.... I did however read
>>>>>> somewhere that tracking the sun with the panel gave about 40%
>>>>>> more
>>>>>> energy than simply having the panel stationary at the optimal
>>>>>> noon
>>>>>> position....
>>>>>> Â
>>>>>> Bjorn Justnes
>>>>>> La Vinzelle
>>>>>> France
>>>>>>
>>>>>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions
>>>>>> <bcountry@...
>>>>>>> wrote:
>>>>>>
>>>>>>
>>>>>> From: Clifford Krolick/ Back Country Excursions <bcountry@...
>>>>>>>
>>>>>> Subject: Re: [microhydro] Very small scale generators.
>>>>>> To: microhydro@yahoogroups.com
>>>>>> Date: Tuesday, November 17, 2009, 5:30 PM
>>>>>>
>>>>>>
>>>>>> Â
>>>>>>
>>>>>>
>>>>>>
>>>>>> Jb
>>>>>>
>>>>>> Certainly for some of us we'll have to do a combination of things
>>>>>> to
>>>>>> create enough Electricity. Has any one heard of using reflective
>>>>>> technology to significantly increase output of photoV panels??
>>>>>> On Nov 16, 2009, at 6:56 PM, JB wrote:
>>>>>
>>>>>
>>>>>
>>>>> ------------------------------------
>>>>>
>>>>> Does your company feature in the microhydro business directory
>>>>> at http://microhydropower.net/directory
>>>>> ? If not, please register free of charge and be exposed to the
>>>>> microhydro community world wide!
>>>>>
>>>>> NOTE: The advertisements in this email are added by Yahoogroups
>>>>> who
>>>>> provides us with free email group services. The microhydro-group
>>>>> does not endorse products or support the advertisements in any
>>>>> way.
>>>>>
>>>>> More information on micro hydropower at http://microhydropower.net
>>>>>
>>>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>>>>> ! Groups Links
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> ------------------------------------
>>>>
>>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>>> ? If not, please register free of charge and be exposed to the
>>>> microhydro community world wide!
>>>>
>>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>>> provides us with free email group services. The microhydro-group
>>>> does not endorse products or support the advertisements in any way.
>>>>
>>>> More information on micro hydropower at http://microhydropower.net
>>>>
>>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>>>> ! Groups Links
>>>>
>>>>
>>>>
>>>
>>>
>>> ------------------------------------
>>>
>>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>> ? If not, please register free of charge and be exposed to the
>>> microhydro community world wide!
>>>
>>> NOTE: The advertisements in this email are added by Yahoogroups who
>>> provides us with free email group services. The microhydro-group
>>> does not endorse products or support the advertisements in any way.
>>>
>>> More information on micro hydropower at http://microhydropower.net
>>>
>>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>>> ! Groups Links
>>>
>>>
>>>
>>
>>
>>
>> ------------------------------------
>>
>> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>>  ? If not, please register free of charge and be exposed to the
>> microhydro community world wide!
>>
>> NOTE: The advertisements in this email are added by Yahoogroups who
>> provides us with free email group services. The microhydro-group
>> does not endorse products or support the advertisements in any way.
>>
>> More information on micro hydropower at http://microhydropower.net
>>
>> To unsubscribe: send empty message to
microhydro-unsubscribe@...
>> ! Groups Links
>>
>>
>>
>
>
> ------------------------------------
>
> Does your company feature in the microhydro business directory at
http://microhydropower.net/directory
>  ? If not, please register free of charge and be exposed to the
> microhydro community world wide!
>
> NOTE: The advertisements in this email are added by Yahoogroups who
> provides us with free email group services. The microhydro-group
> does not endorse products or support the advertisements in any way.
>
> More information on micro hydropower at http://microhydropower.net
>
> To unsubscribe: send empty message to
microhydro-unsubscribe@...
> ! Groups Links
>
>
>

Mark:

Do you have the web Page or link to the Massachusetts trackers ?.

I am interested to get their technical info and prices

Nando



   ----- Original Message -----
   From: Mark Drabick
   To: microhydro@yahoogroups.com
   Sent: Monday, November 23, 2009 4:06 PM
   Subject: Re: [microhydro] Very small scale generators.



   Howdy...........there is a tiny company in Massachusetts that makes trackers
soley for the purpose of reflecting lite into north facing windows........the
trackers are comtrolled by a tiny chip that runs two tiny servo motors and once
the mirrors are oriented correctly the chip is programmed to reflect the sun to
any location without the use of sun position sensors.......pretty nifty......i
think each tracker can hold 32 sq ft of mirrors and uses an average of two
watts.............mark in Orford,NH
   ----- Original Message -----
   From: Frank Leslie
   To: microhydro@yahoogroups.com
   Sent: Monday, November 23, 2009 1:15 PM
   Subject: RE: [microhydro] Very small scale generators.

   There was a photo in Home Power magazine showing that, I believe. The light
was reflected to strike the ceiling of the room being lit.

   Sometimes, things are done just to do it.

   Frank

   ________________________________
   From: microhydro@yahoogroups.com [mailto:microhydro@yahoogroups.com] On Behalf
Of William Wixon
   Sent: Sunday, November 22, 2009 7:54 PM
   To: microhydro@yahoogroups.com
   Subject: Re: [microhydro] Very small scale generators.

   sorry to be diverging from the microhydro topic but this discussion about
   reflecting sunlight touched on something i had wondered just the other day,
   and had wondered about in the past as well, i'm sure there must be a
   downside or it would already be being done, but i wondered why don't people
   put mirrors on a tracking device and just reflect straight sunlight into the
   windows of their home for supplimental heat and light (for example, on the
   northern side of their homes)? im guessing havnig blinding sunlight coming
   in your windows at a low angle would be very distracting and uncomfortable,
   and probably it wouldnt make economic sense to have an expensive tracker for
   the availble BTU's of reflected sunlight.... etc.
   just wondering.
   has it already been done? would it even be possible to track and aim
   sunlight into a window?

   On Sun, Nov 22, 2009 at 1:27 PM, Michael Welch
   <michael_welch@...<mailto:michael_welch%40sbcglobal.net>>wrote:

   > I do not see how you can practically increase one without the other. Just
   > adding more light to the same area of PV cells will also increase the heat.
   >
   > Early in commercial PV history, a rather large utility PV array added
   > stainless steel reflective wings on each side of some standard modules.
   > Failure rates were higher than expected, and the modules started
   > discoloring. The industry learned never to do that again.
   >
   > On the other hand, I have a friend that has had a single Mariposa
   > concentrating module in his 12 V system for maybe 15 years, and last I heard
   > it was doing fine.
   > http://solardyne.stores.yahoo.net/marconmod10k.html
   >
   > Clifford Krolick/ Back Country Excursions wrote at 06:36 PM 11/18/2009:
   >
   > >Michael
   > >
   > >All good points. I was hoping to not increase the heat coefficient
   > >with the reflection. I'm Not thinking about concentrating the light
   > >like a magnifying glass. Just thinking more in line that at a
   > >particular the distance away from the photo units there would be
   > >little or no thermal transfer just light transfer. But probably this
   > >is wishful thinking. What's your take?
   > >
   > >
   > >Cliff
   > >Parsonsfield, Maine, USA
   > >
   > >
   > >On Nov 18, 2009, at 1:13 PM, Michael Welch wrote:
   > >
   > >> 1. Adding reflectors will increase the temperature of the PV cells
   > >> which will decrease the output. It will also shorten the life of the
   > >> modules and probably void any warranty.
   > >>
   > >> 2. Tracking the sun is a good idea if either you have good horizon
   > >> to horizon exposure, or if you need to maximize available power
   > >> either early or late in the day, like in irrigation pumping
   > >> applications. Otherwise, you are probably better off with a fixed
   > >> array and spending the tracker money on more modules instead.
   > >>
   > >> BjornOlaf wrote at 02:02 PM 11/17/2009:
   > >>
   > >>> I am not so sure reflecting light onto the panels would be that
   > >>> effective unless you tracked the sun.... I did however read
   > >>> somewhere that tracking the sun with the panel gave about 40% more
   > >>> energy than simply having the panel stationary at the optimal noon
   > >>> position....
   > >>> Â
   > >>> Bjorn Justnes
   > >>> La Vinzelle
   > >>> France
   > >>>
   > >>> --- On Tue, 11/17/09, Clifford Krolick/ Back Country Excursions <
   > bcountry@...<mailto:bcountry%40psouth.net>
   > >>> > wrote:
   > >>>
   > >>>
   > >>> From: Clifford Krolick/ Back Country Excursions
<bcountry@...<mailto:bcountry%40psouth.net>>
   > >>> Subject: Re: [microhydro] Very small scale generators.
   > >>> To: microhydro@yahoogroups.com<mailto:microhydro%40yahoogroups.com>
   > >>> Date: Tuesday, November 17, 2009, 5:30 PM
   > >>>
   > >>>
   > >>> Â
   > >>>
   > >>>
   > >>>
   > >>> Jb
   > >>>
   > >>> Certainly for some of us we'll have to do a combination of things to
   > >>> create enough Electricity. Has any one heard of using reflective
   > >>> technology to significantly increase output of photoV panels??
   > >>> On Nov 16, 2009, at 6:56 PM, JB wrote:
   > >>
   > >>
   > >>
   >

   [Non-text portions of this message have been removed]

   [Non-text portions of this message have been removed]

   [Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

I have read about the new members and the same old questions.  I would like to
implement a hydroelectric system in our wastewater facility.  Average flow 395
gpm/year, a resovoir of secondary treated wastewater feeding a 28 foot vertical
16" ductile, to a 270 foot horizontal 10" ductile run to Zenon 1000 polishing
filters.  Minimum flow of 230 gpm upto 1050 gpm.  Can the verticle run of 270
feet be used for head pressure?  My math comes up to 10.34 hp. Ideas for the new
guy are welcome, I beleive I can produce electrical output of 480 V, 3 ph power
from 140 million gallons of exceptionally clean wastewater per year.    




[Non-text portions of this message have been removed]

Hi, Frank:
I am in S. Fla. and submit that NO AltEnergy equipment will be covered by
your FWUA policy.  Windmills and solar arrays are the same as lawn chairs
and pool enclosures.  The cost of qualifying such equipment for  Fla. wind
ins. acceptance is like that for UL Listing (over $25K).  Any  equipment we
have installed MUST be removed or SUPER-SECURED in event of  winds over 35 mph.

Hurricane Wilma 'removed' most passive collectors (pool, water heater) here
  a couple years ago, and few were ever replaced.

John Kessler, Ft. Lauderdale


[Non-text portions of this message have been removed]

My name is Scott Davis. I am collecting an anthology of articles about
microhydro to be titled Serious Microhydro: Waterpower Solutions From the
Experts. It will be a companion to my first book, Microhydro: Clean Power From
Water.

I would like to contact Robert Costello, who wrote an article for Home Power
called Off Grid Pioneers. I would like to get his permission to reprint this
article which appeared in 1997.

I can offer him a signed copy of the book as my thanks.

So, if you are Mr. Costello, or can put me in touch with him, please contact me
at scottldavis@....

Cheers,

Scotty

My name is Scott Davis. I am collecting an anthology of articles about
microhydro, to be titled Serious Microhydro: Waterpower Solutions From the
Experts. It's a companion to my first book, Microhydro: Clean Power From Water.

I am hoping to contact R.T. Gaydos or Linda Gaydos for permission to reprint a
1989 article they wrote for issue 11 of Home Power Magazine called Mini Hybrid
Power System.

I can offer my thanks and a signed copy of the book as thanks to them.

So, if you are R.T. or Linda Gaydos, or can put me in touch with them to
scottldavis@..., I'd appreciate it very much.

Thanks and cheers,

Scotty

My name is Scott Davis. I am the author of Microhydro: Clean Power From Water. I
am now working on an anthology of microhydro articles, to be called Serious
Microhydro: Waterpower Solutions From the Experts.

The late Mr. Haveland wrote an article for Home Power magazine in 1999 called
Induction Motors for Small Scale Hydro.

I'd like to contact his family for permission to reprint this fine article. I
can offer a signed copy of the book as thanks.

Please contact me at scottldavis@....

Cheers,

Scotty

Here is a new kind of hydro:

Norway opens world's first osmotic power plant

Tue Nov 24, 2009 7:00am EST

Norway (Reuters) - Norway opened on Tuesday the world's first osmotic power
plant, which produces emissions-free electricity by mixing fresh water and sea
water through a special membrane.

State-owned utility Statkraft's prototype plant, which for now will produce a
tiny 2-4 kilowatts of power or enough to run a coffee machine, will enable
Statkraft to test and develop the technology needed to drive down production
costs.

The plant is driven by osmosis that naturally draws fresh water across a
membrane and toward the seawater side. This creates higher pressure on the sea
water side, driving a turbine and producing electricity.

"While salt might not save the world alone, we believe osmotic power will be an
interesting part of the renewable energy mix of the future," Statkraft Chief
Executive Baard Mikkelsen told reporters.

Statkraft, Europe's largest producer of renewable energy with experience in
hydropower that provides nearly all of Norway's electricity, aims to begin
building commercial osmotic power plants by 2015.

The main issue is to improve the efficiency of the membrane from around 1 watt
per square meter now to some 5 watts, which Statkraft says would make osmotic
power costs comparable to those from other renewable sources.

The prototype, on the Oslo fjord and about 60 km (40 miles) south of the
Norwegian capital, has about 2,000 square meters of membrane.

Future full-scale plants producing 25 MW of electricity, enough to provide power
for 30,000 European households, would be as large as a football stadium and
require some 5 million square meters of membrane, Statkraft said.

Once new membrane "architecture" is solved, Statkraft believes the global
production capacity for osmotic energy could amount to 1,600-1,700 TWh annually,
or about half of the European Union's total electricity demand.

Europe's osmotic power potential is seen at 180 TWh, or about 5 percent of total
consumption -- which could help the bloc reach renewable energy goals set to
curb emissions of heat-trapping gases and limit global warming.

Osmotic power, which can be located anywhere where clean fresh water runs into
the sea, is seen as more reliable than more variable wind or solar energy.

A summit in Copenhagen next month is due to agree on a U.N. pact to combat
climate change by promoting clean energies and a shift from fossil fuels that a
U.N. scientific panel blames for stoking heatwaves, floods, droughts and rising
seas.

http://www.reuters.com/article/environmentNews/idUSTRE5AN20Q20091124

Bob

Hi Clifford. After this, let's get this list back to discussing micro-hydro.

No particular PV module company suggestions. But when shopping look for:
1. Rated power tolerance
It can be extremely disappointing if under even ideal conditions, a 2,000 W
array may only produce 1,820 W if power tolerance is +/-9%. To be assured your
module has the ability to produce the amount of power it is specified for, look
for a narrow (or positive only) power tolerance.

2. Longevity of company
Why buy something with a 25 yr. warranty if the company is not going to be
around to back it up?

3. Module efficiency (necessary if you do not have much room on the roof)
Some modules put out more energy with a smaller footprint.

4. Made in USA (or at least North America, or **maybe** Central America)
Getting harder to find, but worth looking for to decrease embodied energy from
shipping and, in the case of Chinese modules, to decrease the possibility of
poor environmental practices in manufacturing and to decrease the possibility of
overly exploited labor.

5. Testing
Look for modules that have been independently tested to verify output claims. CA
provides this verified info on most UL-approved modules available in the US.
http://www.gosolarcalifornia.org/equipment/pvmodule.html

6. Home Power magazine
The latest HP mag has a listing of all verified modules for companies that have
offices in the US, but does not discuss where a module is manufactured.

Clifford Krolick/ Back Country Excursions wrote at 03:00 PM 11/23/2009:

>Sounds about right to me especially with the cost of panels so low.
>Any suggestions on what  BRAND OR company I might get my best deal and
>quality if I were to purchase very soon?

I would like to contact Katcha Sanderson, for permission to reprint an article
she wrote for Home Power Magazine called Renewable Energy Kiwi Style, which
appeared in 1995.

I am collecting an anthology of articles about microhydro to be titled Serious
Microhydro: Waterpower Solutions From the Experts. It is a companion to my first
book, Microhydro: Clean Power From Water.

I can offer her a signed copy of the book as well as my sincere thanks.

If you are Katcha Sanderson, or can put her in touch with me, please contact me
at scottldavis@....

Cheers,

Scotty

My name is Scott Davis. I am the author of Microhydro: Clean Power From Water,
and now I am collecting an anthology of microhydro articles to be titled Serious
Microhydro: Waterpower Solutions From the Experts.

I would like to contact Jack Knowles to reprint an article he wrote for Home
Power magazine called Central Solar System Serves Four Homes, back in 1991.
Although this article isn't about microhydro exactly, it illustrates a method of
sharing power between households with individual battery/inverter subsystems.
This method could be applied to village scale microhydro systems just as well.

I can offer a signed copy of the book to Mr. Knowles as thanks, so any help I
can get to contact him would be most appreciated. Please contact me at
scottldavis@....

Cheers,

Scotty

My name is Scott Davis. I am collecting an anthology of microhydro articles to
be titled Serious Microhydro: Waterpower Solutions From the Experts. It will be
an excellent companion to my first book, Microhydro: Clean Power From Water.

I am hoping to contact Pete Geddes, who wrote an article for Home Power Magazine
called Self Cleaning Intake Screens in 1999. I can offer him a signed copy of
the book as thanks for permission to reprint this useful article.

So, if you are Pete Geddes, or can put me in touch with him, please contact me
at scottldavis@....

Cheers,

Scotty

John:

There are some discrepancies here, can you clarify them ?.

395 gpm/year ????.

You may be quite familiar with the system and I am not. 28 feet = 8.53 meter.
then you have 270 foot  10 inch pipe -- explain verticle = Vertical ?. of 270
feet for head pressure.

Why don't you detail the math you worked on.

140 million gallons -- explain in detail  we need to know your thoughts .

Nando


   ----- Original Message -----
   From: John Granlund
   To: microhydro@yahoogroups.com
   Sent: Tuesday, November 24, 2009 1:07 PM
   Subject: [microhydro] Re:Preliminary study



   I have read about the new members and the same old questions.  I would like to
implement a hydroelectric system in our wastewater facility.  Average flow 395
gpm/year, a resovoir of secondary treated wastewater feeding a 28 foot vertical
16" ductile, to a 270 foot horizontal 10" ductile run to Zenon 1000 polishing
filters.  Minimum flow of 230 gpm upto 1050 gpm.  Can the verticle run of 270
feet be used for head pressure?  My math comes up to 10.34 hp. Ideas for the new
guy are welcome, I beleive I can produce electrical output of 480 V, 3 ph power
from 140 million gallons of exceptionally clean wastewater per year.

   [Non-text portions of this message have been removed]





[Non-text portions of this message have been removed]

Thanks for your suggestions, makes sense!  Back to microhydro

Cliff
On Nov 24, 2009, at 2:15 PM, Michael Welch wrote:

> Hi Clifford. After this, let's get this list back to discussing
> micro-hydro.
>
> No particular PV module company suggestions. But when shopping look
> for:
> 1. Rated power tolerance
> It can be extremely disappointing if under even ideal conditions, a
> 2,000 W array may only produce 1,820 W if power tolerance is +/-9%.
> To be assured your module has the ability to produce the amount of
> power it is specified for, look for a narrow (or positive only)
> power tolerance.
>
> 2. Longevity of company
> Why buy something with a 25 yr. warranty if the company is not going
> to be around to back it up?
>
> 3. Module efficiency (necessary if you do not have much room on the
> roof)
> Some modules put out more energy with a smaller footprint.
>
> 4. Made in USA (or at least North America, or **maybe** Central
> America)
> Getting harder to find, but worth looking for to decrease embodied
> energy from shipping and, in the case of Chinese modules, to
> decrease the possibility of poor environmental practices in
> manufacturing and to decrease the possibility of overly exploited
> labor.
>
> 5. Testing
> Look for modules that have been independently tested to verify
> output claims. CA provides this verified info on most UL-approved
> modules available in the US.
> http://www.gosolarcalifornia.org/equipment/pvmodule.html
>
> 6. Home Power magazine
> The latest HP mag has a listing of all verified modules for
> companies that have offices in the US, but does not discuss where a
> module is manufactured.
>
> Clifford Krolick/ Back Country Excursions wrote at 03:00 PM
> 11/23/2009:
>
>> Sounds about right to me especially with the cost of panels so low.
>> Any suggestions on what  BRAND OR company I might get my best deal
>> and
>> quality if I were to purchase very soon?
>
>
>
> ------------------------------------
>
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Nando:
Thank you for your interest.  The formula used was  Gross Head X Flow X 0.55
Eff. X 0.085 Constant.
I do not have my horsepower conversion with me today.  We have a wastewater
plant that water is always flowing.  I suggested hydrogeneration and have been
tasked with the preliminary study.  I used a one year average flow.  The
resovoir that provides flow has a 28 foot drop in a 16" cast ductile pipe
reduced to a 10" cast ductile pipe which runs 270 feet to four GE Zenon
ultrafiltration systems.  The effluent is exceptionally clean.  We run from 0
GPM to 1100 GPM based on incoming sewer water.  From one year ago we treated
137 million gallons of wastewater and discharged it.  My thought is to
capitalize on the constant flow and generate power and transform it to 480 volt,
3 phase power to a grid tied electrical system to sell to the grid excess
power and power our plant.  My math is probably wrong but I could use to be
educated.  Any information or direction is appreciated. 
Thank you.
John.




________________________________
From: Nando <nando37@...>
To: microhydro@yahoogroups.com
Sent: Wed, November 25, 2009 1:16:37 AM
Subject: Re: [microhydro] Re:Preliminary study

 
John:

There are some discrepancies here, can you clarify them ?.

395 gpm/year ????.

You may be quite familiar with the system and I am not. 28 feet = 8.53 meter.
then you have 270 foot 10 inch pipe -- explain verticle = Vertical ?. of 270
feet for head pressure.

Why don't you detail the math you worked on.

140 million gallons -- explain in detail we need to know your thoughts .

Nando

----- Original Message -----
From: John Granlund
To: microhydro@yahoogro ups.com
Sent: Tuesday, November 24, 2009 1:07 PM
Subject: [microhydro] Re:Preliminary study

I have read about the new members and the same old questions. I would like to
implement a hydroelectric system in our wastewater facility. Average flow 395
gpm/year, a resovoir of secondary treated wastewater feeding a 28 foot vertical
16" ductile, to a 270 foot horizontal 10" ductile run to Zenon 1000 polishing
filters. Minimum flow of 230 gpm upto 1050 gpm. Can the verticle run of 270 feet
be used for head pressure? My math comes up to 10.34 hp. Ideas for the new guy
are welcome, I beleive I can produce electrical output of 480 V, 3 ph power from
140 million gallons of exceptionally clean wastewater per year.

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]







[Non-text portions of this message have been removed]

John said:  I suggested hydrogeneration and have
been tasked with the preliminary study.  I used
a one year average flow.  The resovoir that
provides flow has a 28 foot drop in a 16" cast
ductile pipe reduced to a 10" cast ductile pipe
which runs 270 feet to four GE Zenon
ultrafiltration systems.  The effluent is
exceptionally clean.  We run from 0 GPM to 1100
GPM based on incoming sewer water.


28 feet gross head

1100 GPM max flow

The 270' of 10" ductile iron pipe will cost you a
couple of feet of gross head at 1100GPM  ... so
estimate a net head of about 26 feet.

26 feet  =  7.925  meters net head

1100gpm   =  ~70 liters per second

liters per second * meters head * 9.8 = theoretical power

70 * 7.925  * 9.8 = 5436 watts * .55 efficiency =
expect about 2990 watts at you maximum flow rate...

The old-standby "English Unit" thumbnail formula
of "Flow in GPM * Head in feet / 11" gives a 2600 watt estimate.

2.6kW * 24 hours * 30 days  = 1872 kW.h per month if you ran 100% max flow.

You could use an 8" Francis turbine ...
absalaskan.com still sells the Nautilus model
made by Ron MacLeod, I think...  an 8" runner
would give slightly better efficiency at lower flows...

MEMBERS:

I am looking for any of the members that may have DC/AC MSW inverters that
are damaged and that are NOT going to be repaired.

I am doing an experiment in where I could utilize some of the internal parts
and I would like to see if any one can "depart" and give  away to me ( I
will pay the postage ) to see if  possible to have a POST Mortem parts
salvage with good use.

If you have one, please describe what you have , rated power -- etc -- I can
take for 12 , 24 or 48 volts Inverters.

This is for the USA members -- to reduce the cost of the mailing.

Thanks  .

Nando

Nandi,

Try xantrex.com authorized service centers in your general area. Am sure they
have tons.

Arte.

On Nov 26, 2009, at 7:51 AM, "Nando" <nando37@...> wrote:

MEMBERS:

I am looking for any of the members that may have DC/AC MSW inverters that
are damaged and that are NOT going to be repaired.

I am doing an experiment in where I could utilize some of the internal parts
and I would like to see if any one can "depart" and give away to me ( I
will pay the postage ) to see if possible to have a POST Mortem parts
salvage with good use.

If you have one, please describe what you have , rated power -- etc -- I can
take for 12 , 24 or 48 volts Inverters.

This is for the USA members -- to reduce the cost of the mailing.

Thanks .

Nando




[Non-text portions of this message have been removed]

Hi all,

I have been a keen reader of posts on here and sadly have not got much to offer
in terms on hydro.

I have a hydro resource that I would like to build a Banki turbine on.

I can do CAD and have a local lazer company that is well priced.

my current efforts are here:

http://www.youtube.com/watch?v=pRogfURdIHc

and a recent up date:

http://www.youtube.com/watch?v=wgf8B_H8-Z0&feature=response_watch

I know the resource could work, in the second video when i enagise the stator
the turbine slows to a point where the magnetic field is dropped.

I would like to build a much more appropriately sized turbine similar to: 
http://www.otherpower.com/scotthydro1.html

I have about 1 meter of head and a varying flow rate, I would like to generate
10 watts to run a wireless nature camera.

If anyone can help with information on how to design Banki turbines or has built
one, I would be very great full.

Jonathan