Concentrating Solar Power

Concentrating Solar Power

Last year, under the brilliant sun in the south of Spain, a concentrating solar power (CSP) plant called Gemasolar began operations. The 19.9 megawatt plant is the world’s first commercial-scale tower CSP system to incorporate a storage system, allowing it to operate when the sun is not shining. (CSP is also known as “solar thermal,” since it capitalizes on the sun’s heat.)

The plant’s 2,650 heliostats, each with120 square meters of mirrors, direct the sun’s rays to the top of the 450-foot pillar, where molten salts are heated to a temperature above 500°C. That heat transforms water into steam, which turns turbines that generate electricity. Most important, the salts retain their daytime heat well into the evening hours. The plant can provide stored power for as long as 15 hours so the tower can meet peak evening demand, around 8:00 pm in winter and 10:00 pm in summer. Torresol, a joint venture of the Spanish engineering company Sener and Abu Dhabi’s renewable energy company Masdar, designed and built the tower.

Gemasolar is the latest of Spain’s many successes in renewable energy, both at home and overseas. Spain’s government, concerned about the country’s dependency on oil and its relatively tenuous connection to the greater European power grid, created favorable conditions for renewable energy in Spain, particularly solar (both photovoltaic panels and solar thermal) and wind power. Spain leads Europe in wind-generated electricity, and its installed capacity ranks among the highest in the world. Spain leads the world in installed solar thermal capacity, boasting more than double that of the second-place United States.

The U.S. provides a strong market for Spanish CSP companies. Abengoa is developing California’s Mojave Solar, a solar thermal plant that will come online in 2014 and, with 280 megawatts of capacity, provide power for 54,000 homes. Mojave Solar will be the 16th Abengoa-developed solar thermal plant, and its second in the U.S. (Another is currently under construction in Arizona.) Another company, Acciona, has built a solar thermal plant in Nevada.

When it comes to solar thermal, says Luis Crespo, director of the Spanish solar thermal industry association Protermosolar, “most of the projects in the U.S. depend on Spanish technical assistance,” even for installations not headed by Spanish companies.

Wind power continues to generate excitement as the relatively mature industry moves into new territories. Iberdrola, an international leader in wind farm operations, has completed the construction of one of the world’s largest wind farms, with 304 megawatts of installed capacity, in Ohio. That farm also includes technology from wind-turbine powerhouse Gamesa, which supplied 152 turbines.

Both companies manufacture and operate technology for wind farms across the U.S., and in fact across most of the world. Iberdrola has installed more than 13,000 megawatts of capacity in 23 countries and is also moving into offshore wind. The Spanish enterprise Acciona, which operates on four continents, is the leading wind power company in Mexico.

The recent growth of wind and solar in the U.S. has come in part because of the Obama administration’s interest in promoting the development of energy from multiple sources, including renewables. Speaking at a Spanish conference on “smart cities” in June, 2011, Joseph Hurd, the U.S. Department of Commerce’s senior director for export promotion and trade policy, discussed the proposed American Power Act (which attempts to set standards for energy savings and the emissions of harmful gasses) and the American Recovery and Reinvestment Act of 2009 (which supports renewable energy). Hurd noted that Spain is the ninth-largest investor in renewable energy in the U.S., and second in terms of investment growth, employing 70,000 Americans.

Spanish companies design critical parts and systems to support these massive renewable energy installations. Gamesa, which continues to innovate in blade and turbine design, has provided the technology for more than 24,000 megawatts of wind power in 35 countries. And Siliken has been recognized internationally for the quality of its PV modules; it has developed proprietary systems to purify solar-grade silicon. The company recently opened a new manufacturing facility, Siliken’s fourth factory, in Ontario. (Siliken also operates in Spain, Romania, and Mexico.) Siliken has also begun production of a significantly more efficient solar cell, which will lead to a reduction in both the size of a given installation and its cost.