The Solar Star projects, formerly known as the Antelope Valley solar projects, are two co-located photovoltaic (PV) solar installations near Rosamond, California, US.
Owned and operated by BHE Solar, a subsidiary of BHE Renewables, the 579MW Solar Star power station is currently the biggest operating solar power facility in the US. At the time of commissioning in 2015, it was also the world’s biggest solar power station.
The Solar Star projects were originally undertaken by SunPower Corporation. BHE Renewables, a subsidiary of Warren Buffet's Berkshire Hathaway Energy (formerly MidAmerican Energy), acquired the project from SunPower in December 2012.
However, SunPower was retained as the engineering, procurement, and construction (EPC) contractor for the projects.
Construction works were started in the first quarter of 2013 and completed in March 2015. The facility commenced partial operations in 2014, while the full-scale commissioning took place in June 2015.
Location and site details
The Solar Star projects are located in the Antelope Valley in southern California that constitutes the western tip of the Mojave Desert.
The PV solar installations are spread over approximately 3,200 acres of privately-owned land in the south-east portion of Kern County and the northern portion of Los Angeles County.
The location was selected due to the high quality of solar resources and very small amounts of rain.
Solar Star power plant make-up
The Solar Star PV power station comprises two separate installations namely Solar Star-1 and Solar Star-2, with respective capacities of 314MW and 265MW.
The 314MW Solar Star-1 installation is located in Kern and Los Angeles Counties, while the 265MW Solar Star-2 facility is located in Kern County.
The power station comprises a total of approximately 1.72 million PV solar modules mounted on single-axis trackers to follow the sun’s movement for efficient solar power generation.
Approximately 137km of new roads were constructed as part of the project.
The technology used in Solar Star projects
The Solar Star projects are developed with SunPower® Oasis® power plant technology, which is a fully-integrated, modular solar technology developed by SunPower for the rapid deployment of utility-scale solar projects with minimum land use.
The Oasis® product uses high-efficiency SunPower® monocrystalline silicon PV panels mounted on SunPower® T0 single-axis trackers, which position the panels to track the sun during the day, increasing energy capture by up to 25%.
The technology is fast to install and enables power generation to the grid even before the plant is fully constructed.
The first phase of the Solar Star projects was synchronised to the California Independent System Operator (California ISO) grid in October 2013, while the facility started sending the entire 579MW of electricity into the California ISO grid in June 2015.
Power purchase agreement
The electricity generated by the Solar Star projects is sold to Southern California Edison (SCE) under two long-term power purchase agreements approved by the California Public Utilities Commission in January 2012.
SunPower, which was the original owner and developer of the Solar Star-1 and the Solar-2 projects, was awarded the engineering, design, procurement, installation, construction and commissioning contracts for both the projects in December 2012.
The EPC contracts were awarded as part of a £1.5bn ($2bn) acquisition deal for the Solar Star projects that was concluded by BHE Renewables and SunPower in the same month.
The contracts also included long-term operation and maintenance (O&M) services, performance guaranty as well as module warranty agreements for both the projects.
Mortenson, a construction and real estate development company based in Minnesota, was subcontracted for the construction of foundations and trackers, and civil works including caisson installation and road construction, as well as for general site management services for the Solar Star projects.
Solar Star project benefits
The two Solar Star projects together deliver enough renewable electricity to power the equivalent of approximately 255,000 Californian homes while displacing approximately 561,000 tonnes of CO2 a year.
The projects created approximately £385m ($500m) in regional economic impact including the creation of 650 jobs during the construction period and 15 full-time operations and maintenance jobs on-site.