Abengoa Solar in early May began commercial operation of Solnova 1, the company’s first 50-MW parabolic trough plant. Covering 980,000 square feet with mirrors requiring an area totaling 280 acres (Figure 2), it is one of five planned concentrating solar power (CSP) plants to be built at the Solúcar Platform in Spain. All will use a technology developed by Abengoa with experience gained from a trough pilot built in 2007. Solnova 1 will also be equipped to burn natural gas if sunlight is weak.

2. A sunny place. Spanish company Abengoa Solar began commercial operation of a 50-MW parabolic trough plant at the Solúcar Platform in Andalucía. The Solnova 1 project comprises 360 collectors. Each is 150 meters long and consists of 28 mirrors. Abengoa said that the troughs were assembled using a “lean manufacturing system,” which enabled one quality collector module to be produced every 30 minutes. Solnova 1 is one of five projects planned for construction at the Solúcar Platform. Work is in progress on the Solnova 3 plant solar field. Courtesy: Abengoa Solar

The technology essentially involves using a long curved mirror to concentrate solar rays onto a heat-absorbing pipe inside the trough, through which flows a liquid that reaches high temperatures. This fluid transfers its energy to the water vapor that reaches a turbo-generator, where it expands to produce electricity. The new plant commenced operation after a three-day test period, during which “plant performance matched theoretical electrical power generation design” Abengoa said, adding that this validates “the tremendous potential of parabolic trough technology.”

The Abengoa-developed ASTRØ parabolic trough collector includes more precision than previous designs because it is built with an “exclusive process of construction and alignment,” Abengoa said.

The company plans to use the experience gained from Solnova 1 and the pilot on two 280-MW CSP plants planned for the U.S. in Arizona and California. The Arizona project, a parabolic trough plant near Gila Bend, and an associated 230-kV transmission line, recently obtained the U.S. Department of Energy’s clearance following a lengthy environmental assessment. The DOE considered 286 pages of referenced impact statements that covered most reasons to obstruct it—but found none that would have a “significant affect [sic] on the human environment.”

Dubbed “Solana,” which means “sunny place” in Spanish, the Arizona project would use some 2,700 trough collectors covering roughly 1,757 acres. It would also employ, unlike the Spanish Solnova 1 project, molten salt storage tanks to retain and store up to six hours of heat to allow owners to dispatch power on cloudy days and after sunset.