How to Run a Generator on Water

A standard home generator uses gasoline to turn a turbine or run an internal combustion engine.

Either one turns a generator, producing electricity. This setup is quite versatile because you can easily refuel the gas engine and turn it on or off quickly; however, it is not environmentally friendly. An older setup using falling water in place of the gas engine can produce electricity. You can easily turn it on or off and it's considerably more environmentally friendly.

Disassemble the old generator to get access to its drive shaft. Fully remove the gas engine.

Connect the output of the clutch to the drive shaft of the generator.

Connect the drive shaft of the turbine to the input of the clutch. Once the turbine starts spinning fast enough, the clutch will engage the generator, producing electricity.

Mount the reservoir above the generator and slightly off to the side. Place the reservoir as high above the generator as possible, like on a high roof or in an attic, to create as much pressure as possible from the falling water at the turbine. The higher pressure will turn the turbine faster, creating more electricity from the same volume of water. Offset the reservoir to prevent any leaks from dropping onto the generator.

Plumb from the drain of the reservoir to the generator with the piping. Insert the valve above the generator in the piping to allow you to turn the water flow, and consequently the generator, on and off.

Plumb from the valve to the turbine's input.

Plumb from the output of the turbine to the drain.

Solder all of the joints in the piping using the solder and blow torch. Test the system for leaks before attempting to use it to produce electricity.

Fill the reservoir, then open the valve to allow water to flow through the turbine. Once the turbine gets up to speed, the clutch will engage, starting the production of electricity. The generator should continue to produce electricity so long as water is flowing through the turbine. This is the basis of a hydroelectric power plant.

Things You Will Need

  • Pipe wrench
  • Screwdrivers
  • Ratchet and sockets
  • Open-end wrenches
  • Clutch
  • Large water reservoir (500+ gallons) with supports
  • Small water turbine (input diameter of 1 inch or less)
  • Piping (same diameter as turbine)
  • Valve (same diameter as piping)
  • Drain
  • Solder
  • Blow torch


  • If you use a pond as the drain and a windmill to fill the reservoir with water from the pond, you can automate the whole system to produce electricity without any pollution.