The world’s largest solar farm, the Ivanpah Solar Electricity Generating System, opened earlier this year in California’s Mojave Desert. The farm, which uses BrightSource Energy’s power-tower solar thermal technology, is comprised of three separate plants spread across some 3,500 acres of desert and will serve around 140,000 homes in California with electricity during peak hours of the day.
Unlike photovoltaics, this system does not convert solar radiation directly into electricity; the 300,000 odd software-controlled mirrors track the sun and focus the sunlight onto solar receivers (boilers) at the top of three 459 foot tall towers. This then heats the water inside the boilers and the resultant steam is used to drive turbines that then generate electricity.
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The complex is estimated to reduce CO2 emissions by more than 400,000 tons per year, which is about the same as taking 88,000 cars off of the road. It also produces less air pollutants, such as sulfur oxides, than natural gas-fired power plants.
Despite this complex being a leap in the right direction towards a greener future and California’s goal of providing one third of all energy through sustainable sources by 2020, some have raised concerns about the potential environmental impacts. Because of the way the towers have been built there has been a limited impact on vegetation and the majority of the natural landscape has been preserved. However, the extreme heat produced around the towers represents a potential hazard for some wildlife, in particular birds, but steps are already being taken to assess the risk and figure out how to keep bird deaths to a minimum.