Fraunhofer Institute for Solar Energy Systems ISE
Most of the solar thermal systems installed are used for hot water preparation or space heating. But process heat from larger solar thermal systems is becoming more and more interesting also for services, industry and agriculture. Depending on collector type and location, operating temperatures in low and mid temperature range can be provided. Thus, a large share of the final energy needed for industrial processes can be generated by solar thermal systems. Improved flat-plate collectors and vacuum tube collectors achieve operating temperatures up to 150 °C. At locations with high direct irradiation, tracked focusing collectors can be applied to generate temperatures up to 400 °C. Therefore, solar process heat markets are different in countries with high and with medium solar irradiation potential.
Typical processes suitable for the integration of solar heat are drying of food or products, cleaning, fermentation, steam generation, as well as desalination and water purification.
In some cases, a combination of solar process heat with solar power generation or solar cooling (polygeneration) can increase the overall economic performance.