Asphalt has enormous amounts of unused heat that is waiting to be tapped. I have seen a few different method's for heating water but I would like to make a system that goes straight to electricity. There is the hot asphalt on top and cold soil underneath and i believe by placing a grid of two dissimilar metals in the asphalt we can create a Seebeck effect and harvest the heat. As of right now this is only a idea and will require some experimentation to see how to produce a cheap way to implement this design.
thin copper wire
thin aluminum or steel wire
A driveway and a battery to store the electricity
so I did some work on it the past few days and have a proof of concept. this is the cheapest option and its a very small amount of electricity but when its scaled up with constant heat from ashphalt or painted concrete this could be a game changer.