Hennigan Engineering was recently awarded a contract to perform services for NextEra Energy at their “Solar Energy Generating Systems” (SEGS) Solar Energy SEGS located in the Mojave Desert of California. The SEGS facility is the second largest solar thermal energy generating system in the world.
The facility is comprised of nine solar power plants that have 354 MW net (394 MW gross) capacity. This is enough power to service 232,500 homes during the day at peak power.
This displaces approximately 3,800 tons of pollution per year that would have been produced if the electricity had bееn provided by fossil fuels.
The facilities have a total of 936,384 mirrors and cover more than 1,600 acres (647.5 ha). Lined up, the parabolic mirrors would extend over 229 miles (369 km). The installation uses parabolic trough, solar thermal technology along with natural gas to generate electricity.
About 90% of the electricity is produced by the sunlight. Natural gas is only used when the solar power is insufficient to meet the demand from Southern California Edison, the distributor of power in southern California.
Heat exchange/transfer efficiency is critical. The sunlight reflects off the mirrors and is directed to a central tube filled with synthetic oil, which heats to over 400 °C (750 °F). The reflected light focused at the central tube is as much as 80 times more intense than the ordinary sunlight. The synthetic oil transfers its heat to water, which boils and drives the Rankine cycle steam turbine, thereby generating electricity. Synthetic oil is used to carry the heat (instead of water) to keep the pressure within manageable parameters.
Hennigan Engineering will mobilize to the site in January 2018 to perform critical heat exchanger tube cleaning services in order to maximize system efficiency and power output.