28 February 2008
Demand, Technology, Tax Credits Drive Global Solar Power Growth
Partnerships, international collaborations building new U.S. solar capacity
Washington -- Technology advances, tax credits and the global demand for clean renewable energy have turned sunshine into one of the world’s hottest commodities, especially in the United States, where installed solar power rose 125 percent between 2006 and 2007.
The nation’s newest 314 megawatts of solar-derived electricity have arisen from public-private partnerships, international collaborations and new and expanding solar energy companies. Most of that growth depends on solar investment tax credits created in the 2005 Energy Bill. The credits are due to expire at the end of 2008.
The Solar Energy Industries Association (SEIA) in Washington is asking that Congress extend the 30 percent federal solar investment tax credit eight years for commercial and six years for residential solar projects.
Some state governments offer tax incentives for solar-power projects to attract solar companies and jobs. At least 37 states have nonresidential direct incentives or commercial tax credits for solar and other renewable energy projects.
California is the Number 1 market, with its $3.3 billion California Solar Initiative, followed by New Jersey, Colorado, Ohio, Michigan, Nevada, New York, Texas and others. But the solar industry wants a federal tax credit.
“The critique,” SEIA spokeswoman Monique Hanis told America.gov, “is, ‘Why not have [a tax credit] at the federal level that would benefit all of the states and all of the citizens and companies operating here?’”
A federal program, the U.S. Department of Energy’s (DOE) Solar America Initiative, seeks to achieve cost-competitiveness for solar technologies across all market sectors by 2015.
SUN POWER
Three of the fastest-growing sun-based technologies are solar thermal, concentrating solar power (CSP) and photovoltaics. Solar-thermal devices use direct heat from the sun to do everything from heating swimming pools to creating steam for electricity generation.
Plants that concentrate solar energy produce electric power by converting sunlight into high-temperature heat using large mirrors, then channeling the heat through a conventional generator. The plants have two parts -- one that collects solar energy and converts it to heat, and another that converts heat energy to electricity.
Sunlight, not heat, fuels photovoltaic cells. The cells, today made mostly of the semiconductor silicon, convert sunlight directly into electricity. In photovoltaics, light particles called photons penetrate the cell and knock electrons free from the silicon atoms, creating an electric current. As long as light flows into the cell, electrons flow out of the cell. The cell does not use up its electrons and lose power, like a battery; instead, converts one kind of energy (sunlight) into another (flowing electrons).
Utility-scale CSP and photovoltaics are on the rise in the United States. In 2006, the Nellis Air Force Base in Nevada, one of the world’s largest fighter bases, unveiled the nation’s largest photovoltaics array. The 14-megawatt plant will supply 25 percent of the electricity used by the base’s population of 12,000 and save taxpayers $1 million a year. Nevada Solar One, a 64-megawatt CSP plant, also went operational in the same year.
The Arizona Public Service Company (APS) will begin drawing power in 2011 from a 280-megawatt CSP plant to be built near Gila Bend, Arizona, by Spain’s Abengoa Solar. Australia’s Ausra Inc. plans to build a manufacturing facility in Las Vegas for CSP components, and Germany’s Schott Solar will build a $100 million manufacturing plant in Albuquerque, New Mexico, to produce parts for CSP and photovoltaic plants.
In Golden, Colorado, the DOE National Renewable Energy Laboratory (NREL) has been working on solar and other renewable technologies since it opened in 1977 as the Solar Energy Research Institute. Its photovoltaics research supports DOE’s goal of reducing the average cost of grid-tied photovoltaic systems from $6.25 per watt to $3.30 per watt for end users. The result will be a reduction in the average cost of electricity generated by PV systems from a current $0.25/kWh to $0.09/kWh.
This goal lines up with one of the world’s 14 grand challenges for engineering in the 21st century, named by a committee of international experts convened by the U.S. National Science Foundation. The challenge? “Make solar energy affordable.”
EMERGING TECHNOLOGIES
In California’s sun-drenched Silicon Valley, high-tech solar energy companies, financed by venture capital and other sources, are springing up to produce a range of advanced technologies.
“As a result, the number of new technologies is growing,” Larry Kazmerski, director of NREL’s National Center for Photovoltaics, told America.gov. “Even technologies people thought they might not see for a while, like in the thin-film area, are real there and are going into manufacturing.”
What Silicon Valley provides, he added, is a group of people who have worked in the semiconductor industry and are bringing their expertise to bear on solar.
“It’s a marriage among the technology, the technologists, the researchers and the people who know how to run a business,” Kazmerski said.
The future of photovoltaic solar cells lies in their light-absorbing semiconducting material, including today’s crystalline silicon wafers or the promising thin films of amorphous silicon, cadmium telluride and copper indium (gallium) diselenide -- what Kazmerski calls disruptive technologies because they overturn existing market standards.
Products can be disruptive by using manufacturing techniques that produce much higher efficiencies than current methods or by using approaches that conserve material -- two things that are already happening at some solar companies in Silicon Valley. Many of the leading-edge solar technologies had their origins at NREL.
“Some of the disruptive technologies on the thin-film side,” he said, “were pushed through the laboratories here to show that they could convert sunlight efficiently into electricity and [determine] the best properties of the devices to do this. Many of the new companies in [Silicon Valley] are using technologies that were developed and demonstrated through this national lab.”
More information about solar technology research is available on the NREL Web site.
Additional information about the Solar America Initiative and solar energy is available on DOE Web sites.
More information about the Solar Energy Industries Association is available on that organization’s Web site.
