CSP-3: ORC Collector and Optical Materials

Solar Energy Research Center for India and the United States (SERIIUS)



Multiscale Concentrating Solar Power



Low-temperature organic Rankine cycle



To develop a cost-efficient parabolic trough solar collector for ORC systems. The targets are: 1) Cost of collector <Rs 5000/m2; 2) Optical efficiency >70 %; 3) Temperature of operation: 200° to 230°C; 4) Thermal loss <2%.

Project Milestones


Reflector development using composite (12 months).


Prototype reflector and testing (24 months).


Reflector material analysis for reflection under bent condition, stress, hail resistance, weather resistance, thermal cycling, and dust (24 months).


Absorber coating development for high absorbance and low emission (36 months).


Weather testing of the absorber coating (48 months).


Testing materials in a prototype parabolic trough (60 months).

Task 1: ORC collector and optical materials

Development of a flexible reflector to get high optical efficiency with a new reflector material, a suitable support structure for this reflector that retains focus accuracy, and a low-temperature weatherproof absorber material. To achieve high optical efficiency >92% in a parabolic shape, development of a flexible mirror using composite glass/plastic/aluminum that can be shaped without breaking and can maintain optical reflectance. The approach is choosing the right quality reflector material, composite, and process of formation of mirror. A prototype of the reflector will be made and tested for accuracy. The parabolic trough design will be developed to suit the reflector.

The second development is the receiver coating, which is a key to achieving high net efficiency. A cost-effective selective coating with >95% absorbance and <5% emission is targeted for development. A novel process of nano-coating using a hybrid of materials will be developed.