[Paul Junkin] bought a curious product off the Internet. It was supposed to generate electricity when hooked up to a running hose. Only, it didn’t do a very good job. His solution was straightforward—he built his own hose-powered generator that actually worked.
The design uses a turbine hooked up to a small motor acting as a generator. To maximize the transfer of energy from the stream of water to the blades of the turbine, the hose is hooked up to a convergent nozzle. [Paul] does a great job explaining the simple physics at play, as well as the iterative design process he used to get to the final product. He calculates the best-case power coming out of his hose around 50 watts, so for his turbine to collect 22 watts is a win, and it’s good enough to charge a phone or run some LED lighting.
Of course, this isn’t a practical generator if you have to pay …