Solar Thermal Tube Collector VIESSMANN VITOSOL 200-T SP2A 3,03M2

A solar thermal collector collects heat by absorbing sunlight. The term “solar collector” commonly refers to a device for solar hot water heating, but may refer to large power generating installations such as solar parabolic troughs and solar towers or non water heating devices such as solar air heaters

Non-concentrating collectors

The collector area (the area that intercepts solar radiation) is the same as the absorber area (the area absorbing the solar energy/radiation). Solar energy systems for heating water or air usually have non-concentrating collectors. Flat-plate collectors are the most common type of non-concentrating collectors for water and space heating in buildings and are used when temperatures lower than 93C (200°F) are sufficient.

Flat-plate solar collectors usually have three main components:

• A flat metal plate that intercepts and absorbs solar energy
• A transparent cover that allows solar energy to pass through the cover and reduces heat loss from the absorber
• A layer of insulation on the back of the absorber to reduce heat loss

Solar water heating collectors have metal tubes attached to the absorber. A heat-transfer fluid is pumped through the absorber tubes to remove heat from the absorber and transfer the heat to water in a storage tank. Solar systems for heating swimming pool water in warm climates usually do not have covers or insulation for the absorber, and pool water is circulated from the pool through the collectors and back to the pool.

Solar air heating systems use fans to move air through flat-plate collectors and into the interior of buildings.

Concentrating collectors

The area intercepting solar radiation is greater, sometimes hundreds of times greater, than the absorber area. The collector focuses, or concentrates, solar energy onto an absorber. The collector usually moves throughout the day so that it maintains a high degree of concentration on the absorber. Solar thermal power plants use concentrating solar collector systems because they can produce the high temperature heat needed to generate electricity.