We are just getting started in using roofs and other surfaces as “panels”. So we can expect lots of improvements to this technology as we use it more. Already, the costs of producing solar panels has fallen tremendously as the demand scaled up. Though there are some doubts whether these costs will fall further. But that is not the only game in town here. Solar panels don’t just produce electricity. They generate heat as well. So no surprise, some folks think we can harvest that heat as well. And they are starting to do just that. It is called an “integrated solar panel” as it integrates technology to capture electricity and heat.