Free Heat For Your Pool! The Sun2Solar Ground Solar System Kit is designed to be used on above-ground or in-ground pools. Each kit is made of one - 2 x 20 panel. Panel is made of lightweight durable black polyolefin. The panel s tube construction creates a larger surface area which optimizes heat transfer from the sun to your pool. Your pools pump and filter system circulates pool water through the solar panels when it is heated and then returned to your pool. You can add extra panels if needed. Use of a solar cover is recommended for maximum efficiency.