UC Merced Update

Winston Unveils Innovative Solar Cooling Project


Roland Winston with solar researchers

UC Merced Professor Roland Winston, left, and a team of student researchers designed and developed a system of non-tracking solar thermal collectors.


Using solar thermal energy to power an air-conditioning unit can be difficult and expensive. But UC Merced Professor Roland Winston and his team of student researchers have added a game-changing advance to the process that could make it easier, less costly and more effective.

Winston and his team have designed and developed a system that gathers and concentrates sunlight onto specially made collector tubes. The heat generated can then be transformed using existing technology for cooling, heating and a number of other potential uses.

The key factor in their design is this: The collectors are stationary. Typically, solar collectors must move and track the sun to achieve optimal energy production, necessitating additional equipment that can be costly to install and complex to maintain.

The UC Merced design — called an External Compound Parabolic Concentrator (XCPC) — generates solar thermal efficiency of 60 percent at temperatures up to 400 F, achieving thermal performance previously seen only in tracking systems. And in contrast to tracking systems that work only on clear, sunny days, the UC Merced design can work in hazy conditions because it “sees” most of the sky, allowing collection of both direct and indirect sunlight.