Solar collector stationary system efficient as solar tracking systems
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. A team of researchers from the University of California, Merced, have developed an entirely stationary system which is equally effective as solar tracking systems while being much simpler and affordable.
UC Merced Professor Roland Winston and his team of student researchers have designed and developed External Compound Parabolic Concentrator (XCPC) – 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.
XCPX generates solar thermal efficiency of 60 percent at temperatures up to 205°C (400°F), achieving thermal performance of solar collectors with tracking systems. And in contrast to tracking systems that work only on clear, sunny days, the External Compound Parabolic Concentrator can operate in hazy conditions because it is capable to collect both direct and indirect sunlight.
“For any application that requires process heat, the XCPC system is potentially a very cost-effective way to reduce conventional fuel consumption and greenhouse gases. Its non-tracking design also enables it to be installed in any number of ways, including on rooftops and walls. You don’t have this type of architectural flexibility with tracking thermal systems”, said Winston.
In order to demonstrate the efficiency of their system, Winston’s team installed an array of 160 External Compound Parabolic Concentrators in two parallel rows in order to provide power for air conditioning unit which cools a mobile office trailer at their facility at Castle in Atwater. The air conditioning used in the demonstration comes from a high-performance, double-effect absorption unit which requires a significant heat source to generate cooling.
“Solar thermal technology can also have a very positive effect on air quality”, said Heather Poiry, who lead the students on this project nd is in the process of completing her master’s degree in mechanical engineering at UC Merced while studying under Winston. “And I think being able to create this technology right here and know we can make an impact here in the Valley is very important to all of us.”
The utilization of solar thermal energy is constantly growing across the world, and developments like the one described in this article contribute to their affordability and lower their payback time (which currently ranges from 3 to 10 years depending on the amount of insolation in particular region).