Micro Hydroelectric Systems to 100kW

Micro-Hydro Systems Navigation

First-Time Hydropower Project?

Learn basic design
principles in the
Guide to Hydropower

Hydro-Related Formulas and Conversions

Computational help for hydroelectric system design

(Also see Resources for Hydroelectric Professionals)

Simple Power Formulas

Theoretical Horsepower* (HP) = HEAD (feet) x FLOW (cfs)

8.8

Theoretical Kilowatts* (kW) = HEAD (feet) x FLOW (cfs)

11.81

* Note that these are Theoretical Power equations (also called Gross Power), which do not account for the inevitable efficiency losses that will occur at various points within a hydro system.   Multiply Theoretical Power times Efficiency to get Net Power:

Net Power = Theoretical Power x Efficiency

Unit Conversions

Power

1 horsepower

=

746 watts

1 kilowatt

=

1.341 horsepower

1 kilowatt

=

1,000 watts

1 megawatt

=

1,000,000 watts

Head Pressure

1 foot head

=

0.433 pound/square inch

1 pound/square inch

=

2.31 feet head

Flow

1 gallon/second

=

0.1337 cubic feet/second

1 gallon/second

=

8.021 cubic feet/minute

1 gallon/second

=

0.0038 cubic meters/second

1 gallon/second

=

0.227 cubic meters/minute

 

1 gallon/minute

=

0.01667 gallons/second

1 gallon/minute

=

0.1337 cubic feet/minute

1 gallon/minute

=

0.0022 cubic feet/second

1 gallon/minute

=

0.0038 cubic meters/minute

1 gallon/minute

=

3.785 liters/minute

 

1 cubic foot/second

=

7.481 gallons/second

1 cubic foot/second

=

0.0283 cubic meters/second

1 cubic foot/second

=

1.699 cubic meters/minute

 

1 cubic foot/minute

=

0.1247 gallons/second

1 cubic foot/minute

=

0.01667 cubic feet/second

1 cubic foot/minute

=

0.0283 cubic meters/minute

 

1 cubic meter/second

=

1,000 liters/second

1 cubic meter/second

=

2.118.9 cubic feet/minute

1 cubic meter/second

=

264.17 gallons/second

1 cubic meter/second

=

15,850.32 gallons/minute

 

1 liter/second

=

0.264 gallons/second

1 liter/second

=

0.0353 cubic feet/second

1 liter/second

=

2.119 cubic feet/minute

1 liter/second

=

0.001 cubic meters/second

Distance

1 meter

=

3.28 feet

1 foot

=

0.305 meter

1 yard

=

3 feet

Volume

1 gallon (US)

=

3,785.41 cubic centimeters

1 gallon (US)

=

0.003785 cubic meters

1 gallon (US)

=

0.134 cubic feet

1 gallon

=

3.7854 liters

 

1 cubic centimeter

=

0.000264 gallons

1 cubic centimeter

=

0.001 liter

1 cubic meter

=

264.172 gallons

1 cubic meter

=

1,000 liters

 

1 cubic foot

=

7.481 gallons

1 cubic foot

=

28,317 cubic centimeters

1 cubic foot

=

0.0283 cubic meters

1 cubic foot

=

28.3168 liters