When selecting solar panels, give priority to efficiency, as it dictates how much sunlight is transformed into energy. More efficient solar panels are more costly, but they need less space. There are different types of panels: monocrystalline has the highest efficiency, polycrystalline is cheaper, and thin-film panels are flexible. In addition, make sure to check the rated power, warranty (both product and performance), and temperature coefficient, since panels tend to generate less power during high heat. Also, consider the manufacturer's and installer's reputation for reliable quality and support.