A couple in Cornwall attempts to convert a dilapidated farmhouse in several acres of meadowland to a system that keeps them self-sufficient.
One of the products they look at is Energy Guard, a device for domestic electricity production that shows how much electricity is flowing to/from the National Grid.
One of their means of producing their own electricity, on a tiny budget and with low maintenance costs, is a water wheel. It should be able to produce around 60W continuously, and with battery storage should provide enough for powering the house lighting in the evenings.