Water generator and Solar power questions

Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl
and/or other groups to ask in? How about solar generators? How practical is it to use either or both?
Note: I'm aware of Google, and Dogpile, etc, but would still appreciate any specific sites and groups people are willing to recommend.

dh@. wrote:

Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl
and/or other groups to ask in? How about solar generators? How practical is it to use either or both?
Note: I'm aware of Google, and Dogpile, etc, but would still appreciate any specific sites and groups people are willing to recommend.

http://www.realgoods.com/renew/shop/product.cfm/dp/1200/sd/1201/ts/1017104
if you have apprpriate conditions, hydro is most practical. wind is next, followed by solar.
-- Steve Spence Dir., Green Trust, http://www.green-trust.org Contributing Editor, http://www.off-grid.net http://www.rebelwolf.com/essn.html

On Thu, 20 Oct 2005 12:37:24 -0400, dh@. wrote:

Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl
and/or other groups to ask in? How about solar generators? How practical is it to use either or both?

Depends on your site. There are devices you can use to check your location to measure how appropriate it is for either type.

Note: I'm aware of Google, and Dogpile, etc, but would still appreciate any specific sites and groups people are willing to recommend.

On Thu, 20 Oct 2005 12:37:24 -0400, dh@. wrote:

Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl

As far as I know this unit is not especially efficient - just convenient in some situations. "good sources"? - there are many water powered electric generators (also called hydropower units) - but availability might depend on what country you are in .

and/or other groups to ask in? How about solar generators? How practical is it to use either or both? It really depends what you mean by "practical".

If you can manage your house/home with 2.4 Kwh of electrical energy a day - well yes! - I suppose its practical (I run a holiday home on about that amount with lpg cooking and wood heating.)
You might need about six time the solar generation capacity in most situations, to equal the output of hydro - and probably a bigger battery as well - if it is stand-alone.

Note: I'm aware of Google, and Dogpile, etc, but would still appreciate any specific sites and groups people are willing to recommend.

Steve Spence' site is very useful, also homepower.com
Eric Sears

Eric Sears wrote:

On Thu, 20 Oct 2005 12:37:24 -0400, dh@. wrote:
Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl .... and/or other groups to ask in? How about solar generators? How practical is it to use either or both?
It really depends what you mean by "practical". If you can manage your house/home with 2.4 Kwh of electrical energy a

Luxury! We live well on 1.5kWh / day.

day - well yes! - I suppose its practical (I run a holiday home on about that amount with lpg cooking and wood heating.)

Propane cooking, hot water & fridge and oil/solar heat. An electric fridge would probably get us close to that 2.4kWh/day (we already have a small electric freezer).

You might need about six time the solar generation capacity in most situations, to equal the output of hydro - and probably a bigger battery as well - if it is stand-alone.

Typical solar gain in the US/southern Canada is in the realm of 4 hours/day or less, so at least six times the capacity.
That particular generator seems pretty expensive for so little power - my Air-X (marine) can put out more power than that for the same sort of money. I've never really looked into hydro generators because my stream is seasonal, but I always expected them to be cheaper per watt. -- derek

On Fri, 21 Oct 2005 09:30:09 -0300, Derek Broughton wrote:

Eric Sears wrote:
On Thu, 20 Oct 2005 12:37:24 -0400, dh@. wrote:
Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl ... and/or other groups to ask in? How about solar generators? How practical is it to use either or both?
It really depends what you mean by "practical". If you can manage your house/home with 2.4 Kwh of electrical energy a
Luxury! We live well on 1.5kWh / day.
day - well yes! - I suppose its practical (I run a holiday home on about that amount with lpg cooking and wood heating.)
Propane cooking, hot water & fridge and oil/solar heat. An electric fridge would probably get us close to that 2.4kWh/day (we already have a small electric freezer).
You might need about six time the solar generation capacity in most situations, to equal the output of hydro - and probably a bigger battery as well - if it is stand-alone.
Typical solar gain in the US/southern Canada is in the realm of 4 hours/day or less, so at least six times the capacity.
That particular generator seems pretty expensive for so little power - my Air-X (marine) can put out more power than that for the same sort of money. I've never really looked into hydro generators because my stream is seasonal, but I always expected them to be cheaper per watt.

I don't even understand how it all works. I have 3 115 amp hour trolling batteries I use with an inverter to run my TV etc when I take the boat out. But I don't understand how to calculate how long they would run a 1.5KW space heater, or how many more I'd need to make it practical if three isn't enough, or how to calculate what it would take to run it for how long, or how to monitor the batteries so I know not to overcharge them, etc. I really need to learn those basics before I'll be able to think about it in any detail. The idea is to save money, but if I do it wrong it will probably cost more. My original idea was to get water to turn an alternator, since alternators are already set up to charge 12V batteries...and supposedly set up to not overcharge them...

In article , Steve Spence wrote:

dh@. wrote: Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl
and/or other groups to ask in? How about solar generators? How practical is it to use either or both?
Note: I'm aware of Google, and Dogpile, etc, but would still appreciate any specific sites and groups people are willing to recommend.
http://www.realgoods.com/renew/shop/product.cfm/dp/1200/sd/1201/ts/1017104
if you have apprpriate conditions, hydro is most practical. wind is next, followed by solar.

The system you show is used in a flowing stream. For hydropower the first thing you need to do is find out what you have available in the way of water. Until you have the velocity (in meters per second) or head (fall in meters) and flow (in L per second) you can't find out how much energy is present. When you can come back with these numbers some of us can help you in what type of system you need.

Mike Swift wrote:

...For hydropower the first thing you need to do is find out what you have available in the way of water. Until you have the velocity (in meters per second) or head (fall in meters) and flow (in L per second) you can't find out how much energy is present.

Head and flow are almost enough to know power.
Nick

Mike Swift wrote:

Steve Spence wrote: dh@. wrote:
Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl
http://www.realgoods.com/renew/shop/product.cfm/dp/1200/sd/1201/ts/1017104
if you have apprpriate conditions, hydro is most practical. wind is next, followed by solar.
The system you show is used in a flowing stream. For hydropower the first thing you need to do is find out what you have available in the way of water. Until you have the velocity (in meters per second) or head (fall in meters) and flow (in L per second) you can't find out how much energy is present. When you can come back with these numbers some of us can help you in what type of system you need.

Another thing is that the above turbine is extremely wasteful. It may be suitable if you have a lot of hydro power you can do without. The first thing is to know the head from a barrier to the generator. Low head, high volume and you would use a turbine. High head and low volume and you are probably better off with a pelton wheel.
In the coastal foothills of CA where realgoods is based, most resources are better met with a pelton wheel from what I've seen.
Best, Dan.

Dan Bloomquist wrote:

Mike Swift wrote:
Steve Spence wrote:
dh@. wrote:
Can anyone suggest any good sources for water powered electric generators like this one:
http://tinyurl.com/akthl
http://www.realgoods.com/renew/shop/product.cfm/dp/1200/sd/1201/ts/1017104
if you have apprpriate conditions, hydro is most practical. wind is next, followed by solar.
Another thing is that the above turbine is extremely wasteful. It may be suitable if you have a lot of hydro power you can do without. The first thing is to know the head from a barrier to the generator. Low head, high volume and you would use a turbine. High head and low volume and you are probably better off with a pelton wheel.
In the coastal foothills of CA where realgoods is based, most resources are better met with a pelton wheel from what I've seen.
Best, Dan.

It may be wasteful, but if you have lots of flow without much head, it's a simple, appropriate solution.
-- Steve Spence Dir., Green Trust, http://www.green-trust.org Contributing Editor, http://www.off-grid.net http://www.rebelwolf.com/essn.html

nicksanspam@ece.villanova.edu wrote:

Head and flow are almost enough to know power.

respectfully request you strike the word "almost"

wrote:

Head and flow are almost enough to know power.
respectfully request you strike the word "almost"

Velocity matters too, no? A 10 L/s sheet of water that meanders over rocks for a kilometer at 0.1 m/s while falling 1 meter and losing power by friction has less available power than a 10 L/s water column that drops 1 m from a pipe.
Nick

In article , wrote:

dances_with_barkadas@yahoo.com> wrote:
Head and flow are almost enough to know power.
respectfully request you strike the word "almost"
Velocity matters too, no? A 10 L/s sheet of water that meanders over rocks for a kilometer at 0.1 m/s while falling 1 meter and losing power by friction has less available power than a 10 L/s water column that drops 1 m from a pipe.

Technically, this is "speed," not velocity. (Basic physics.)
But head and flow are by far the most important things, especially within a defined region. For example, within someone's property. (Unless someone is wealthy enough to own an entire stream course, the relevant details are nearly all captured in head and flow.)
There are a bunch of equivalent ways of viewing energy...power times time, force times distance, etc., but, basically, it comes down to "mgh," the mass of the falling water (flow times time) times g times h (the height, or head).
(Energy is not power, of course. Energy is power times time, the integral of power. So the "mgh" translates to power in the obvious ways.)
What is lost in frictional heating of the rocks, blah blah blah, is a small but easily calculated loss.
Relating to what someone said earlier about stream power being the first choice, this is obviously not so. Only a small number of people live near appropriate streams, with appropriate head and flow, and which they have legal access to. Wind and solar are less encumbered by "water rights." Solar is the most predictable, for most people. Wind is mostly OK for pumping water, where it is most often used.
--Tim May

Tim May wrote:

Velocity matters too, no? A 10 L/s sheet of water that meanders over rocks for a kilometer at 0.1 m/s while falling 1 meter and losing power by friction has less available power than a 10 L/s water column that drops 1 m from a pipe.
What is lost in frictional heating of the rocks, blah blah blah, is a small but easily calculated loss.

I disagree, and invite you to calculate the difference.
Nick

In article , wrote:

Tim May wrote:
Velocity matters too, no? A 10 L/s sheet of water that meanders over rocks for a kilometer at 0.1 m/s while falling 1 meter and losing power by friction has less available power than a 10 L/s water column that drops 1 m from a pipe.
What is lost in frictional heating of the rocks, blah blah blah, is a small but easily calculated loss.
I disagree, and invite you to calculate the difference.

I have, several times. Most recently, for my hill's water system.
Without a lot more details about the rocks you talk about, no basis for a detailed calculation.
Fact is, the OP was correct in saying that "head" and "flow" encompass most of the critical issues.
And as I said, this is even more obviously so over the necessarily small run of a private piece of land. Gibbering about the energy losses from the top of the Himalayas to the outlet of the Ganges is not relevant to the situation of a stream with a dam and a wheel or turbine in a length that one would find in a reasonablel set-up.
You're a buffoon.
--Tim May