Modular power generation.
This idea is based on very old tried and true principles of physics. Hydroelectric power has been around for a long time. The man who invented the modern world, Nicola Tesla, also invented a very novel turbine. Imagine the average home owner putting a large low slung water tank on top of their house. A 2 inch ID pipe descends 8 feet into a Tesla Turbine. The Tesla Turbine outlet goes into another tank. At the top of the upper tank is a sensor that turns the water valve to open. At a point lower is a sensor to turn the valve closed. Elevated water = energy. The Home owner invests enough money to trickle charge the system at first. A small pump powered by some solar cells will pump water back to the top tank. The generator will only run when the upper tank is full and turns off when there is insufficient water pressure. This won't run continuously at first but it will run a meter backwards enough times during the month to save a significant portion of money on electricity. The savings can be applied to more water pumping devices. I have a slew of ideas for those. Stirling engines powered by parabolic mirrors, bales of hay, the difference in temperature between ambient and 6 ft under, etc. Make the devices modular and readily addable. Over time, by adding pump modules to the system, the home owner will have continuous free power. Since this technology does not depend on expensive batteries or fuel cells it is cheap enough for most people to afford readily without loans. Because it is modular it is feasible to be done by most home owners in the developed world.
Reward: Continuous free power. What more can one ask for? Ok, I would like a job in the industry created. That would be great!