Watt Generator Head
A look at what is currently available on eBay
![]() Tapered Cone MeccAlte 15,000 Watt Generator Head #193312 US $895.00
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![]() MeccAlte 10200/12000 Watt Generator Head S20W-130T US $699.00
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![]() Cylinder Head Meijer Shop Force 1000 Watt Generator US $9.49
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![]() 6500 watt replacement generator head 8125 watt surge US $319.99
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![]() PTO Driven MeccAlte 7200/9000 Watt Generator Head With Outlets #PTO7 US $999.00
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Hydro Power Formula 80ft head 22 gpm?
I have been looking at making a hydro turbine but unsure if it would be worth it? It has a head of 80 ft and 22 gpm and assuming 90% efficiency on the generator and turbine how many watts a hour would I produce?
I have done the dozen different calculators online and get different results on all of them.
Thank You in Advance
The total energy available, measured in water horsepower Pwhp is given by:
Pwhp = SG x Q x h / 3960
where
Q = volume flow rate (gpm)
SG = specific gravity
h = head (ft)
SG is approximately 1.00 for water, so the water HP is:
Pwhp = 1.00 x 22gpm x 80ft / 3960 = 0.4444 water horsepower
Assuming 90% overall efficiency of conversion, and using the exact conversion factor of 1HP = 746W, yeilds a power output of :
0.4444HP x 746W/HP x 90% = 300W (rounded)
I think the 90% assumption is optimistic. I suggest the following numbers:
generator: 90%
turbine: 70%
overall: 90% x 70% = 63%
Then output power is:
P = 0.4444HP x 746W/HP x 63% = 210W (rounded)
The second link is a vendor of small hydro systems. They have a formula for estimating power out, as follows:
Head (feet) * Flow (gpm) * .113 = power (watts)
Thus:
80ft x 22gpm x 0.113 = 200W (rounded)
The 200W agrees closely with the 210W calculatoin.














