Concentrated solar power (CSP) plants have the potential to reduce the consumption of non-renewable resources and greenhouse gas emissions in electricity production. In CSP systems, a field of heliostats focuses solar radiation on a central receiver, which is ultimately transferred to thermal electrical power plant at high temperature. However, the maximum receiver surface fluxes are low (30–100 W cm−2) with high thermal losses, which has limited the market penetration of CSP systems.
Recently, small (∼ 4 cm2), laminated micro-channel devices have shown potential to achieve concentrated surface fluxes over 100 W cm−2 using supercritical CO2 as the working fluid. The present study explores the feasibility of using these microscale devices as building blocks for a megawatt scale (250 MW thermal) open solar receiver. This allows for a modular design of the central receiver with non-standard shapes customized to the heliostat field. The results show that the microscale unit-cells have the potential to be scaled to megawatt applications while providing high heat flux and thermal efficiency. At the design incident flux and surface emissivity, a global receiver thermal efficiency of > 90% can be achieved.