Ivanpah solar electric generating system is a 392MW thermal solar power plant located in Mojave Desert, US. It is the world’s biggest solar thermal power tower system and has an annual generation capacity of 940,000MWh.

The solar power facility is jointly owned by NRG Energy, Google, and Brightsource, while NRG Energy is the operator.

Construction of the $2.2bn Ivanpah solar power facility began in October 2010 and the operations were commenced in December 2013.

Electricity generated by the project is meeting the requirements of approximately 140,000 Californian homes. The complex is helping the environment by offsetting carbon dioxide (CO2) emissions of more than 400,000 tons a year.

The project created more than 2,600 construction jobs and 61 permanent jobs, in addition to creating benefits of $350m in local and state taxes.

Ivanpah solar electric generating system location and details

Ivanpah solar electric generating system is situated on a public site of 3,471 acres in Ivanpah dry lake.

It consists of three separate units with three towers of 450ft-high each. The capacity of the first unit is 126MW, while the other two units are capable of producing 133MW each.

The facility includes 173,500 heliostat mirrors and a 123MW SST-900 steam generator set. In addition to producing steam, the generator also helps for a flexible operation during load swings and frequent starting and stopping.

Sun light will be reflected by the mirrors onto the water-filled boilers on the towers. Water inside the boiler will be heated resulting in the generation of high temperature steam. The steam is transferred to a conventional turbine through pipes for producing electricity.

Technology utilized

The Ivanpah project applies Luz Power Tower 550 technology (LPT 550) and solar receiver steam generators to produce superheated steam.

The LPT 550 technology also features a dry-cooling system, which converts the steam back into water that also helps in reducing water consumption by 90%.

Power purchase agreements

The electricity generated from the Ivanpah solar power facility is sold to local utilities Pacific Gas and Electric (PG&E) and Southern California Edison (SCE).

The total sale amounts to more than 2,600MW, of which  PG&E purchases two-thirds, while the remaining is sold to SCE.

Financing of the Ivanpah solar electric generating system

The Ivanpah solar electric generating system received a conditional loan of $1.6bn from the US Department of Energy.

NRG Solar made an equity investment of more than $300m in the power facility, while Google invested $168m.

Bechtel made an equity investment in the project in September 2009 through its financing arm Bechtel Enterprises. Other investors include Alstom ($55m) and the California State Teachers Retirement System (CalSTRS).

Contractors involved

Bechtel constructed the Ivanpah solar electric generating system under an engineering, procurement and construction (EPC) contract awarded in September 2009.

Siemens is the supplier of the SST-900 solar-powered steam turbine generator for the solar project, while Riley Power, a subsidiary of Babcock power, provided three boilers.

Cone Drive is the supplier of gear boxes for the heliostats, while Gestamp Renewables is responsible for the pre-fabricated steel frames for the heliostats.

SPX Cooling Technologies supplied the air-cooled condensers, while Prospect Steel provided the structural steel, joists, and furnishings for the towers.

Las Vegas Paving conducted the earthworks, while Elementary Energy provided the electrical equipment for the Ivanpah solar electric generating system.