These are the ideas I've had so far:

 - A product that can store energy relatively cheaply in order to make existing power generation more consistent, like a battery, or pumped water storage. Can also be used in along with another product to store energy for one household.

 - Smaller scale water turbines built for personal power generation from smaller rivers.

 - Small scale solar panels for powering individual homes.

 - A product where a human can turn a wheel to generate electricity, like a hand crank or stationary bike.

 - a simple heat engine that can generate electricity from any heat source.