Solar thermal collectors convert the sun's energy into heat. Every collector consists of three layers, each with a different task:

The surface layer of the collector is made of special safety glass, and protects the elements below from the weather. Sunlight penetrates the glass and reaches the specially-coated absorption sheets below. These absorb the sun’s energy and pass it on to the copper pipes underneath, where it heats the thermal transfer fluid that is pumped through them.

To increase the area of contact between the pipes and sheets, the pipes are laid out in a meandering way. This speeds up the heating process and makes the system more efficient.