Does anyone have experience with micro-hydro in a similar situation?
We have alittle more information about the farm on our website:
Construct an aqueduct to carry the water mostly level until there is enough vertical space to put in a 4 - 6' overshot water wheel.
Use a ram pump to get water up to an elevated storage, then use that potential energy supply to run water wheels, compress air, refrigeration
Put up a dam, grow fish, shrimp, crayfish, veggies aquaponic-style, use the outlet of the dam to still get your power.
Do all 3
I'm sure there are a lot of other potential uses with that large an energy supply.
Since we are in Colorado, everything to do with water must go through the state water court. It can takes years and thousands of dollars and still might be denied. But if we can come up with a plan that does not divert water from the stream, we might have a chance. The aqueduct or pipeline idea would probably not fly. Some kind of water wheel in the creek might be approved but we can't imagine how it would work in the water with all the ice and snow.
Please keep the ideas flowing! I know someone has already done what we need to do.
Thanks to all!
Basically it's a pond that is 4 feet or more deep, with two layers in it. The bottom layer has about 20% salt, the top layer is fresh water. Eventually you end up with a salty bottom layer, a transition zone, and a top mostly fresh layer.
It works like this:
Sun shines on the surface, the energy is absorbed by the bottom of the pond. The cool part is the density difference. Because the salt water is heavier than the fresh water, it is prevented from moving throughout the vertical layers of the pond.
If it were all salty or all fresh, it would absorb heat, then convect it back to the atmosphere through the surface over time. But because the bottom water doesn't move, it just builds and builds (up to a point). So, you have a bottom layer that is somewhere in the neighborhood of 150-200 degrees F, and a top layer that is around the ambient air temperature.
Now you have a relatively constant source of heat differential, and you can use that to drive a heat exchanger, a fluidyne pump, or a turbine. Personally, I'm interested in power generation.
In terms of area required for a given amount of power, it's fairly low efficiency. Theoretical limits are about 17%. But digging a hole, putting in some insulation and a liner is pretty cheap.
Let's say between the actual pond and your turbine, you have 8% efficiency. The sun shines down at 1 kW/square meter. The average home in America uses something like 5 kW hrs per day.
So, with some math... 1 kW/sq m * pi*r^2 sq m * 8 / 100 * 4 sun hrs / day = 5 kW hrs...
r = 2.23 m
d = 14.6 ft.
So, if you have a 15 ft pond, you could power the average American home forever with occasional top-ups of water and salt, and doing some maintenance on a turbine.
And there is always this odd thing about needing to bleed off the excess electricity. It's too bad that there cannot be some system that supports the ponding of water and you could just run enough water through to use and what you don't use stays in the pond.
OTOH: I met a fella with micro hydro and he said that he had enough power to power ten to twenty homes. I thought that was really interesting: imagine that you have a freaky abundance of electricity? Unlimited electric heat, electric cooking, electric hot water, run your lights as long as you want.
In the winter you would probably wouldn't be able to use it. Someone mentioned those in-stream turbines. If the turbine is sited on the bottom of the river, it will continue to work year round as long as it stays below the ice level.
In Colorado it is illegal to remove water from a stream or river. Creating a pond would require a lengthy process through the state water court and probably would not be approved due to the evaporation loss. Water in the West is serious business!
And I bet saltifying a pond would be even harder to get approved
The Colorado, isn't that the river that dries up before it reaches the ocean? We're talking about a heavily over-used resource here, and I appreciate your looking for appropriate ways to use it without abusing it.
Ernie's lived on a homestead with micro-hydro here in Oregon; he first suggested a millrace, but that raises the same problems with removing water from the stream.
You may be able to do a small generator in a culvert or pipe, sunk under the water level at a point where it's flowing strong and deep. A screw-type turbine might work. You won't get forced-water speeds out of it, but you can siphon off some of the flow speed and get some power for your needs.
Storage is the big issue with alternative power: battery banks are expensive. Dams are the obvious answer; stored water keeps a long time, except for evaporation and warming, and you can even use excess power to pump some of the water back up for re-use. The hydro-power dams on the Columbia serve as a reserve for time of peak demand.
But they're hell on fish, and on a stream's ecology.
Are you mitigating your needs for winter heat with passive solar too? You can get some fantastic sun exposure at altitude, and if you're getting that much ice I imagine you have some sparkly-clear nights and days.
Solar heating of black pipes can get you hot water, which is a good thermal battery for heating other things too.
Any chance of working with wind at that elevation?
But you asked about micro-hydro. Good luck with that project.