concentrated solar power
Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver. Electricity is generated whe ...
(CSP) facility in the
Mojave Desert
The Mojave Desert (; ; ) is a desert in the rain shadow of the southern Sierra Nevada mountains and Transverse Ranges in the Southwestern United States. Named for the Indigenous peoples of the Americas, indigenous Mohave people, it is located pr ...
in
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
, about northwest of Barstow. Surrounding the hamlet of Lockhart, Mojave Solar is adjacent to Harper Lake and the SEGS VIII–IX solar plant.
The site was originally reserved for the planned, never built, SEGS IX and XII. For 15 years following its construction in 1990, SEGS VIII–IX was the largest commercial solar power plant in the world, generating around 160 MW at its peak. It is one of three separately owned sites within of one another, that make up the nine solar fields in the Solar Electric Generating System (SEGS #1 and 2 are at Daggett, and #3 through 7 are at Kramer Junction). Harper Lake was the last of these built, and is designated as SEGS #8 and 9. It is still online, but has been surpassed by other newer facilities, including the Mojave Solar Project.
MSP, with a combined
nameplate capacity
Nameplate capacity, also known as the rated capacity, nominal capacity, installed capacity, maximum effect or gross capacity,MW (gross 280 MW), is made of two, independently operable, solar fields. The power plant cost an estimated $1.6 billion in total and entered commercial operation in December 2014. The developer, Abengoa, has successfully secured a $1.2 billion loan guarantee from the US government for the project.
The plant is expected to generate 617,000
MWh
A kilowatt-hour ( unit symbol: kW⋅h or kW h; commonly written as kWh) is a non-SI unit of energy equal to 3.6 megajoules (MJ) in SI units, which is the energy delivered by one kilowatt of power for one hour. Kilowatt-hours are a commo ...
of power annually, enough power for more than 88,000 households and to prevent the emission of over 430 kilotons of CO2 a year. Pacific Gas & Electric has agreed to a 25-year power purchase agreement.
The plant was commissioned on 1 December 2014.
Technology
Using the desert's
solar thermal
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in Industrial sector, industry, and in the residential and commercial sectors. Solar thermal collectors are classified ...
energy, the facility generates steam in solar steam generators, which expands through a steam turbine generator to produce electrical power from twin, independently operable solar fields, each feeding a 125 MW power island. Generation is provided 100% from sun, no supplement from fossil-based energy sources. There is a gas-fired auxiliary boiler, for each field, only to provide equipment and heat-transfer fluid (HTF) freeze protection, when temperatures fall below .
The power cycle is a Rankine-with-reheat
thermodynamic cycle
A thermodynamic cycle consists of linked sequences of thermodynamic processes that involve heat transfer, transfer of heat and work (physics), work into and out of the system, while varying pressure, temperature, and other state variables within t ...
from heat supplied via heat-transfer fluid, solar field heated up to . When operating, the transfer fluid enters the solar field at about . The
steam generator
Steam is water vapor, often mixed with air or an aerosol of liquid water droplets. This may occur due to evaporation or due to boiling, where heat is applied until water reaches the enthalpy of vaporization. Saturated or superheated steam is inv ...
steam exit temperature is about .
Each field utilizes 1128 solar collector arrays (SCA) sited on about . Each SCA, model E2 from Abengoa (derived from Luz's LS-3), is long and is made of 10 solar collector elements (SCE), long each and aperture. The E2 steel frame collector with monolithic glass reflector panels, yields a total aperture area of . That makes a total of aperture each solar field, total for the plant, operating about 3,024 hours per year.
Cooling is provided by wet cooling towers; water for the towers and solar collector washing, is supplied from onsite groundwater wells. Water from condensed steam exits the cooling tower pump at about , before cycling back to the steam generator.
Production
Mojave Solar Project production is as follows (values in
MW·h
A kilowatt-hour ( unit symbol: kW⋅h or kW h; commonly written as kWh) is a non-SI unit of energy equal to 3.6 megajoules (MJ) in SI units, which is the energy delivered by one kilowatt of power for one hour. Kilowatt-hours are a commo ...
).
Maximum production was planned at 617,000
MW·h
A kilowatt-hour ( unit symbol: kW⋅h or kW h; commonly written as kWh) is a non-SI unit of energy equal to 3.6 megajoules (MJ) in SI units, which is the energy delivered by one kilowatt of power for one hour. Kilowatt-hours are a commo ...
Solar thermal energy
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in Industrial sector, industry, and in the residential and commercial sectors. Solar thermal collectors are classified ...