Parabolic trough power plants are large-scale solar power plants (10 MW to > 100 MW) for the centralized generation of electricity. Parabolic trough power plants consist of a solar field and a power plant unit and can be equipped with a thermal reservoir.

In the solar field, solar radiation is transformed into thermal energy. The field consists of many parabolic trough collector units arranged in parallel, which are individually and uniaxially tracked to follow the path of the sun. The thermal energy collected in the solar field can be stored for the hours without sun.

A collector unit is up to 200 m long and consists of several individual collectors connected in series, each typically measuring 8 m to 20 m in length. The uniaxial and parabolically curved mirrors concentrate the solar radiation (approx. 80 fold) on an absorber pipe arranged in a focal line. Circulating within this pipe is a temperature-resistant synthetic oil that is heated to approx. 400 °C by the concentrated radiant energy of the sun.

The thermal energy coming from the solar field can be stored in a thermal reservoir for hours or even days. It is thus possible to use the irregular presence of solar radiation (due to temporary cloud cover, day/night cycle) to generate electricity almost constantly.

In the power plant block, the thermal energy coming from the solar field is transformed into electrical energy. Heat exchangers produce superheated steam that drives conventional steam turbines and the generators connected to them.

The strength of parabolic trough power plants in centralized electricity generation is measured in hundreds of megawatts.

The costs of generating electricity, as well as interest rates and the amortization period, are largely dependent on the solar radiation factors of the location at hand.

This technology possesses even more potential for considerable cost savings. While today’s power generation costs lie between roughly 0.15 €/kWh and 0.19 €/kWh (depending on solar radiation conditions), future plants are expected to see long-term costs reach below 0.10 €/kWh.