Non-tracking East-West XCPC solar thermal collector for 200 celsius applications

• Published in: Applied energy 2018-04, Vol.216, p.521-533
• Main Authors: Widyolar, Bennett, Jiang, Lun, Ferry, Jonathan, Winston, Roland
• Format: Article
• Language: English
• Subjects: CPC; Industrial process heat; Nonimaging; Solar heat industry; Solar thermal; XCPC
• ISSN: 0306-2619; 1872-9118
• DOI: 10.1016/j.apenergy.2018.02.031

•Novel ±40° stationary medium temperature solar thermal collector designed.•Absorber geometry optimized, selective coatings compared, down-selected.•Prototype collector manufactured and experimental performance is tested.•Demonstrates 62% optical efficiency, 50% efficiency at 200 °C, stagnation at 333 °C.•IPH application installs at $0.58/watt with 3.01 cents/kWh LCOH over 20 years. The design and development of a commercial-ready medium-temperature solar thermal collector, the external compound parabolic concentrator (XCPC), is presented in which a nonimaging reflector is paired with an evacuated tube absorber for efficient and low-cost heat collection between 100 and 250 °C. The absorber geometry is optimized under the constraint of being assembled with an ultrasonic welding machine, with a final pentagon-shaped absorber selected. The modified absorber shape, gap loss, and truncated reflector result in a geometric efficiency of 93% compared to an ideal CPC. The final prototype has a 4.56 m2 aperture and simulations predict an optical efficiency of 71% and thermal efficiency of 50% at 200 °C. Experimental test results (optical, thermal, stagnation) have confirmed an optical efficiency of 62% and a thermal efficiency near 50% at 200 °C with a final stagnation temperature of 333 °C. A detailed economic analysis reveals the technology can be installed for $0.58/watt and deliver a levelized cost of heat at 3.01 cents per kWh over a 20 year lifetime. This is equivalent to the current cost of natural gas in the United States, which underscores the potential of this technology to assist in decarbonizing the thermal energy sector.