A new 290-million watt concentrating solar plant will soon be built in the Harquahala Valley 75 miles west of Phoenix, Arizona, representing one of the largest concentrating solar plants in the world.
The project, a cooperative effort between regional utility Arizona Public Service (APS), Lockheed Martin, and the Starwood Energy Group Global, will produce enough electricity to power more than 73,000 homes.
The Harquahala Valley, located in Maricopa County, is a vast tract of land encompassing wilderness retreats, sites where tourists can find Indian artifacts, and hiking trails, including the Ben Avery trail (named for the noted Arizona outdoor writer), which cuts through the heart of the 100,600-acre Eagletail Mountain Wilderness and wolf sanctuary.
The solar array will occupy 1,900 acres of the Valley, and comprise 3,500 parabolic mirrors which focus solar thermal energy onto a heat transfer fluid which will convert water into steam to turn the plant’s turbines. In this respect, it will be much like a traditional power plant; in every other respect, the Starwood Solar I will be a paradigm of clean, non-polluting solar energy.
The Starwood Solar I will also use molten salt to store solar energy, like the revolutionary Andasol I located in Granada, Spain and developed by Solar Millenium AG, a German firm. Molten (or molted) salt allows huge amounts of energy storage because salt, unlike oil, has a melting point of about 1452 degrees (Fahrenheit, or about 800 degrees Celsius). This will allow Starwood to continue producing energy for up to six hours after the sun goes down, or during a period of high energy usage, given Arizona’s hot evenings.
The project announcement, at Arizona State University's Walter Cronkite School of Journalism, saw APS President and COO stating that the utility wants to help make Arizona the “solar capital of the world”. Given Arizona’s clear skies and 360 days per year of sunshine, the goal doesn’t seem in the least farfetched.
The proposed facility will, if approved, be completed in 2013 and owned by an affiliate of Connecticut-based Starwood Energy Group Global, a private equity investment firm specializing in energy infrastructure investments. All the electricity generated by the facility will be fed into APS’s grid via a long-term power purchase agreement.
Lockheed Martin, a global security company global engaged in researching, designing, developing, manufacturing and integrating advanced technology systems, will design, build and operate the facility.
Starwood Solar I is the second APS power purchase agreement for energy from a concentrating solar power plant. In February of 2008, APS signed an agreement with the Spanish company Abengoa Solar for the power from the proposed Solana Solar Plant, a 280-megawatt solar facility which will be sited near Gila Bend, Arizona and scheduled for completion in 2012. Together, Starwood and Solana will provide enough electricity to serve 143,000 customers, putting Arizona well ahead of the curve in solar power generation.
Concentrated solar power is a burgeoning market, with analysts predicting the emergence of just such niche markets for solar power over the next five years. In fact, The U.S. Department of Energy estimates that there may be as much as 20 gigawatts of concentrating solar capacity by 2020 worldwide, with much of it focused on premium solar areas like Arizona, Texas, New Mexico and Southern California.