Potential of Solar Thermal Energy for CCHP Systems

Integrated energy systems combine distributed power generation with thermally activated components to use waste heat, improving the overall energy efficiency, and making better use of fuels. Use of solar thermal energy is attractive to improve combined cooling, heating, and power (CCHP) systems performance, particularly during summer time since the cooling load coincides very well with solar energy availability. Limitation of the use of solar systems is mainly related to high first cost and large surface area for solar energy harvesting. Therefore, solar thermal CCHP systems seem to be an alternative to increase the use of solar thermal energy as a means to increase energy systems overall efficiency and reduce greenhouse gases (GHGs) emissions. This study focuses on the use of solar collectors in CCHP systems in order to reduce PEC and emission of CO₂ in office buildings. By using a base CCHP system, the energy and economic analysis are presented as the contribution of the solar system from the baseline. For comparison purposes, the analysis is made for the cities of Minneapolis (MN), Chicago (IL), New York (NY), Atlanta (GA), and Fort Worth (TX). Results show that solar thermal CCHP systems can effectively reduce the fuel energy consumption from the boiler. The potential of solar collectors in CCHP systems to reduce PEC and CO₂ emission increases with the cooling demand; while the effectiveness of solar collectors to reduce primary energy consumption and CO₂ emission, and the ability of the system to pay by itself from fuel savings, decreases with the number of solar collectors.