Fresnel solar heat for industry
The majority of European industrial applications require only low to moderate temperatures that potentially could be supplied using concentrated solar power. However, current equipment is poorly suited to industrial settings, which generally require small installations. The EU-funded FRESH NRG (Fresnel for solar heat with new receiver and geometry) project developed a suitably efficient new linear Fresnel collector (LFC) system. Innovations consisted of an anti-reflective coating for the glass envelope, other high-absorbance coatings, an optimised collector design and various other process improvements. Work involved designing, testing and implementing the system. A new type of manufacturing system utilised new procedures to reduce costs and improve mirror optical accuracy. The team incorporated the improvements into a prototype, which also includes new control logic components to optimise energy output. The prototype LFC system was installed and operated in Jordan. In addition, the team established two further prototypes in Germany and Italy. The resulting solar system achieved 60 % efficiency at 250 °C. Coatings achieved the desired transmittance, absorbance and emittance values of 96 %, 95 % and 7 %, respectively. The new LFC design achieved a concentration factor of more than 90, which limited heat losses. The mirror design proved safe, durable and efficient. FRESH NRG produced a system able to provide efficient, low-temperature solar heating suitable for many industrial applications.
Keywords
Solar heat, Fresnel collector, FRESH NRG, receiver, absorbance
