The Solana Solar Thermal Power Plant in Arizona has a 280 MW production capacity, it is one of the largest in the world, the largest type of parabolic cylinder and the first in the United States with thermal energy storage. Its construction began at the end of 2010, as part of a project developed by the Spanish engineers of Abengoa Solar. In Arizona this plant is able to cover the peak of the air conditioning from 8 p.m. until bedtime.
This solar thermal plant implements CSP technology (Concentrating Solar Power), using a system of parabolic trough collectors that rotate autonomously with the movement of the sun, these mirrors have the mission of reflecting the sunlight on a tube containing a synthetic fuel, which heats up to temperatures. over 370 ° C
Solar thermal does not produce electrical energy directly, it produces heat and then this heat is transformed into electrical energy. Heat is inexpensive to store. Some tanks with molten salts which have a great caloric value. Heat is used to heat water to produce steam. Steam is used to run steam turbines, thereby generating electricity.
The molten salt storage tanks that trap heat provide electricity when there is no sunlight. They can stay warm for 6 hours.
The plant began operating in October 2013, providing renewable energy to more than 70,000 homes, reducing CO2 emissions by 475,000 tonnes / year. The plant is estimated to have a useful life of 30 years. It has an area of 777 hectares, with 3,200 parabolic trough collectors / mirrors. The collectors measure 122 m, a width of 5.4 m and a height of 5.7 meters. It has 12 molten salt storage tanks with a diameter of 42.6 m and a height of 13.7 m.
Solar thermal energy is already able to compete in price without having to be subsidized.
Images via arstechnica.com