Solar thermal process heating with the external compound parabolic concentrator (XCPC) – 45 m2 experimental array performance, annual generation (kWh/m2-year), and economics

• Experimental performance of 45 m 2 non-tracking solar thermal array described. • Performance evaluated at 80 °C, 135 °C, and 170 °C in dirty and clean conditions. • Annual thermal generation estimated 1000 kWh/m 2 at 100 °C and 700 kWh/m 2 at 160 °C. • $300/m 2 installed, $6.5/m 2 annual O&M, levelized cost of heat 2–4 cents per kWh. • Applications in desalination , evaporation, steam generation, process heating. In this paper, the experimental performance of a 45 m 2 solar field of non-tracking external compound parabolic (XCPC) collectors installed at the University of California, Merced is described. The solar field was operated during July-August 2020 in both clean and dirty conditions and at varying operating temperatures (70, 135, 170 °C) while operating an air heater, thermal evaporator, and double effect absorption chiller. Performance data was used to develop an instantaneous solar field performance model which was then incorporated into an annual performance model using TMY3 data to estimate yearly production from the solar field. The model predicts an annual generation of ∼1100 kWh/m 2 -year at 80 °C, ∼1000 kWh/m 2 -year at 100 °C, ∼900 kWh/m 2 -year at 120 °C, ∼800 kWh/m 2 -year at 140 °C, and ∼700 kWh/m 2 -year at 160 °C in California. The XCPC technology is currently expected to have an installed cost of $300/m 2 and an annual operations and maintenance cost of $6.5/m 2 -year. Over a 25 year lifetime it provides a levelized cost of heat at 2–4 cents per kWh th delivered. This is below the cost of commercial natural gas in California and at temperatures ≤ 120 °C below the cost of industrial natural gas, which highlights the potential of the XCPC technology for decarbonizing thermal applications such as water and space heating, drying, sterilization, desalination, evaporation, low pressure steam, double effect absorption chilling, process heating, and more. The lifetime cost of emissions reductions is ∼$169 per metric ton of avoided CO 2 when replacing natural gas, ∼$137/MT CO 2 when replacing propane, and ∼$83/MT CO 2 when replacing electric heating.