The Southern California Gas Company, the largest natural gas distribution company in the U.S., has become the first utility in that country to test Cogenra’s solar cogeneration solution for cooling purposes. The system will provide air conditioning for SoCalGas’s Energy Resource Center (ERC). Until now, the technology has been mainly applied to solar hot water, space heating and electricity.
The idea is to add an element of multitasking to a solar system, in order to maximize its output and value. With Cogenra's cogeneration system, captured and stored heat is used to run the air conditioning system, instead of electricity. Ordinarily, silicon solar PV panels convert on average 15 percent of the sun’s energy into electricity, while the rest is discarded as waste in the form of heat. Cogenra’s technology captures this waste and transforms it into hot water.
Although it may sound strange that hot water may be used for cooling purposes, that’s how it works, as absorption chillers then use heat to evaporate water. The cooler fluid will then circulate and absorb heat from its surroundings, consequently cooling the building. It’s not just the building that gets cooled, though. The PV components also benefit from it, as this type of approach boosts their generation efficiency and lifespan.
The demonstration 20 SunDeck module system has a 50.2-kilowatt capacity and was installed on top of the ERC, which has a capacity to accommodate 700 people. The concentrating solar PV system combines photovoltaic panels, concentrating optics, single axis tracking and a thermal transfer system. Because it’s modular and small, this type of system requires less space than flat-panel PV systems, yet its dual production capability (heat and electricity) makes it more efficient.
The Center was created over a decade ago to educate businesses about energy efficiency and solutions. The system will help it offset electricity costs as well as reduce peak demand, which accounts for more than 30 percent of the bills. Cogenra says cogeneration can benefit a range of industries, including hospitality, heathcare, food industry and governmental agencies, to name a few.