Gas Company tests solar power innovations in Downey

DOWNEY - The Gas Company on Tuesday showcased two innovative technologies, one developed in Honolulu, Hawaii by Sopogy, Inc. and the other in Cambridge, England by HelioDynamics Ltd., that use concentrated solar power to produce low-cost, green, cool air, as in air conditioning - definitely a hot topic these hot summer days."They are the only ones of their kind," said Sempra Energy utilities spokesperson Denise King, "and are the first of a number of different technologies [we] will test." The multi-year testing will be conducted at the utilities group's Energy Resource Center here in Downey. Regarding the center's role, The Gas Company's manager of technology development David Berokoff has been quoted as saying: "The center showcases resource-efficient innovations, serving as a 'dynamic living lab'". In this case, Sopogy uses parabolic trough solar collectors, while HelioDynamics uses flat reflecting mirror solar collectors, but both use mirrors and sensor-equipped tracking systems to capture the sun's energy and focus the sunlight onto a tube that contains water. Here is how The Gas Company describes the rest of the process: "The resulting hot water is piped to a storage tank and is used in the absorption air-conditioning process to provide cooling for the building. Absorption cooling systems use the solar-heated water in place of electricity or natural gas to boil a salt-water solution. This boiling process takes place in a generator, similar to a compressor driven by an electric motor in a conventional air-conditioning process. "The vapor generated from the boiled salt-water solution flows to a condenser. When the salt-water solution is condensed, it rejects heat and cools down. The solution then travels to a vacuum evaporator. When the salt-water solution is evaporated it absorbs heat from the water and thereby chills to provide cooling. "Finally, the vapor turns to water, which is absorbed by the salt in an absorber. The salt-water solution returns to the generator to repeat the process. This absorption cooling process is similar to the electric cooling process. The difference is that heat is used instead of electricity as the power source." As a comparison, according to King, the process is capable of providing 10 tons of cooling to the Energy Resource Center, or enough air conditioning to cool three average-sized homes. What's more, the solar/thermal process provides cooling in the middle of the day when it is most needed, helping reduce energy usage during hours when electric rates peak. All told, total cost savings of at least 50 percent to a business is possible, King said. Sopogy's estimate of its solar to thermal efficiency is in the 60 percent range, while losses through piping, pipe fittings, friction and heat exchanger equipment amount to about 10 percent. Data of this sort will be monitored throughout the testing period, to see where further efficiencies can be effected vis-?†-vis state standards. Validation of the processes and confirmed system durability and efficiencies will go a long way towards government approval and thus potential tax incentives, funding, etc. According to HelioDynamics representative Ed Robertson, the company's prototype process has also already been installed in Athens, Greece, Albuquerque, N.M., and Phoenix, Ariz. "Places where there's a lot of sunlight will benefit most from this," he said. "In 2010," said King, "electric generation capability will be added to the test site," while noting "New advances in solar collector designs will become available in the future." The expected desired payoffs will be the same: cost savings, greater efficiencies and reduced carbon footprint.

********** Published: July 24, 2009 - Volume 8 - Issue 14