Pumping to a storage tank

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• Solar Expert Posts: 5,436 ✭✭✭✭
Re: Pumping to a storage tank

1 gpm at what pressure?

I suspect that 1 gpm even at 100 psi has little power available.

1 gpm would be 1440 gallons per day.

Tony
• Banned Posts: 17,615 ✭✭
Re: Pumping to a storage tank

There is not enough potential energy here to make it worth the capital investment. Micro hydro takes a lot of water to make it feasible, usually requiring 50' of head or more. Here's one example of a "low head" turbine:

"This micro-hydro generator is for those with low head but high volume installations. It can utilize a maximum of 1000 GPM falling 10 feet to produce 1kW of power."

It costs \$3,000.

So if 1000 GPM makes 1kW, than 1 GPM makes 1W. (Not exactly, of course, but you get the idea).
• Registered Users Posts: 20
Re: Pumping to a storage tank

I must admit I don't know anything about how a micro-hydro system works.

"This micro-hydro generator is for those with low head but high volume installations. It can utilize a maximum of 1000 GPM falling 10 feet to produce 1kW of power. It costs \$3,000"

I'm curious, if the storage tank were higher, would it require less water then? For example say 500 GPM falling 20 feet to produce 1kW of power?
The OP stated the vertical lift from pump to storage tank was 190 feet. If my assumption is correct, it would utilize around 52 GPM falling 190 feet to produce 1kW of power?
If we only needed to run this system overnight, we'd only drain 8-10 hours worth... (around 25k gallons)

If it doesn't work that way let me know, I'm totally shooting in the dark here, lol.
• Banned Posts: 17,615 ✭✭
Re: Pumping to a storage tank

The "falling 10 feet" is the "head". There is a trade-off between head pressure and flow: you need something of each, but can exchange some of one for some of the other to get the same net mechanical energy. The tricky bit is that for optimum power the turbine must be designed for either high flow rate or high pressure. If you feed one type of turbine with the other type of water flow you get poor results.

BTW, the first thing any turbine does is eat up some of that mechanical power just to run. That's why the output scale isn't linear, and higher power units are more efficient over-all - providing you have the water flow to run them.

The main problem with applying this to the OP's set-up is that he's filling water troughs; the flow out of the tank won't be constant and won't be at full flow most of the time (valves at trough open/close as needed). For a turbine to work you have to spin it up to speed and keep it going, otherwise you'll be running at a very low efficiency rate and losing potential power to re-starting the turbine every time the water starts to flow again.
• Solar Expert Posts: 452 ✭✭
Re: Pumping to a storage tank

I can't help it! Here goes...
...the turbine must be designed for either high flow rate
AMPS
or high pressure.
VOLTS

An imperfect but often used analogy.:D

K
• Banned Posts: 17,615 ✭✭
Re: Pumping to a storage tank

'Struth!