to generate some amount of electricity by heating one of its sides by holding to sunlight?
I am using solar harvesting as well but this is to be used as backup.
any advice with regard to this would be so much appreciated.
I didn't test it, but I expect that an industry standard peltier module can work well as a thermal generator. It has however a specific thermal resistance, means it needs a certain heat flow to achieve a reasonable temperature diference between cold and hot side.