A $1.45 billion loan guarantee has been finalized for Abengoa Solar Inc.’s Solana project, the world’s largest parabolic trough concentrating solar plant.
Molten salt is used in solar power tower systems because it is liquid at atmosphere pressure; it provides an efficient, low-cost medium in which to store thermal energy; its operating temperatures are compatible with todays high-pressure and high-temperature steam turbines; and it is non-flammable and nontoxic. In addition, molten salt is used in the chemical and metals industries as a heat-transport fluid, so experience with molten-salt systems exists for non-solar applications.
The uniqueness of this solar system is in de-coupling the collection of solar energy from producing power, electricity can be generated in periods of inclement weather or even at night using the stored thermal energy in the hot salt tank. The tanks are well insulated and can store energy for up to a week. As an example of their size, tanks that provide enough thermal storage to power a 100-megawatt turbine for four hours would be about 30 feet tall and 80 feet in diameter. Studies show that the two-tank storage system could have an annual efficiency of about 99 percent.
Abengoa Solar Inc., the project sponsor, estimates that the Solana project will create between 1,600 to 1,700 new construction jobs and over 60 permanent jobs. The jobs created by the project will be located in Arizona and in neighboring states. To accommodate the project’s need for over 900,000 mirrors, a mirror manufacturing facility will be built outside of Phoenix.
U.S. providers and manufacturers will supply 70 percent of Solana’s components, such as mirrors, receiver tubes, and the heat transfer fluid. Electricity from the project will be sold through a long-term power purchase agreement with Arizona Public Service Company.
“The finalization of the DOE loan guarantee is a major milestone for both Abengoa and Arizona Public Service, which will purchase the power output of the plant,” said Julia Hamm, President and CEO of the Solar Electric Power Association. “The addition of 250MW of solar electric capacity to the APS portfolio will be a great thing for the company’s customers as well as the whole state of Arizona,” said Hamm.
“Storage technologies can play a crucial role in modernizing our nation’s electric grid, including increasing the value of solar electricity to the purchasing utility. The storage capacity of the Solana plant will allow it to provide power to the grid during times of passing cloud cover and help serve APS’s peak demand by providing power even after the sun goes down,” Hamm added.
Abengoa Solar is currently building the largest solar platform in Europe. Located just outside of Sanlúcar la Mayor, Seville, this solar thermal and photovoltaic installation complex will have a nominal power output capacity of 300 MW, obtained through tower technology, parabolic trough collectors, and photovoltaic technology.