Collecting solar heat for factories

EU-funded scientists are investigating the potential of a cost-effective concentrating solar power (CSP) system to meet industrial needs within the context of the project 'Fresnel for solar heat with new receiver and geometry' (FRESH NRG). Target specifications are operation up to 250 degrees Celsius and collector efficiency greater than 50 %.

The linear Fresnel collector (LFC) is similar to the parabolic trough, the most mature solar collector. Both rely on mirrors to focus the Sun's light, but the LFC employs many small mirrors rather than a few larger ones. Scientists are advancing the state of the solar receiver, the LFC geometry and the mirror panels, and developing modular plug-in designs to simplify transport and installation.

New receiver coating technology will fill a current gap for medium-temperature applications. In addition, FRESH NRG is developing an unprecedented lean manufacturing system including coating equipment, receiver assembly and mirror production that will be co-located to reduce manufacturing and prototyping costs.

Activities in the first reporting period witnessed intensive development of the receiver and collector tube. The receiver collects CSP from the primary Fresnel reflectors and uses it to heat water in the collector tube. Development of the anti-reflective coating for the receiver tube proved quite challenging, but is close to final objectives. It will be an important contribution and is expected to lead to a patent application.

The receiver design turns out to be compatible with commercially available CSP receiver tubes. This means the same collector can be used in the original concept, but also with CSP-type tubes for applications greater than 250 degrees Celsius. Now, meeting collector performance and cost targets are easily within reach.

FRESH NRG technology for low-cost solar heating targeted at industrial heating, cooling and electricity needs is well on the road to laboratory and field testing. Achieving targeted efficiency and performance at a reasonable cost will provide major incentive to numerous industries to invest in the technology. Widespread market uptake will have important benefits for manufacturers, industry and the environment.