An image of solar panels on the roofs of houses in Davis, California.

There are two types of solar thermal collectors. The first, known as "flat plate collectors," contain absorber plates that use solar radiation to heat a "carrier fluid," either a liquid like oil or water, or air. Because these collectors can heat carrier fluids to around 80^o C, they are suited for residential applications. The second type of solar collectors are known as concentrating collectors. These panels are intended for larger-scale applications such as air conditioning, where more heating potential is required. The rays of the sun from a relatively wide area are focused into a small area by means of reflective mirrors, and thus the heat energy is concentrated. This method has the potential to heat liquids to a much higher temperature than flat plate collectors can alone. The heat from the concentrating collectors can be used to boil water. The steam can then be used to power turbines attached to generators and produce electricity, as in wind and hyroelectric power systems.