Researchers at Colorado State University are creating a reliable and inexpensive renewable energy source that could greatly reduce humankind’s dependence on fossil fuels. Photovoltaics, a free-standing alternative power supply, also has the potential to better meet the energy needs of the world’s six billion people, one-third of whom live without electricity.
Professor W.S. Sampath and his research group at the Materials Engineering Laboratory at Colorado State have developed a manufacturing technology to efficiently produce low-cost, high-power photovoltaic solar cells. According to Sampath, photovoltaics, the new generation of solar energy, can be one of the most affordable and efficient energy sources of the future.
"Without moving parts or external fuel, photovoltaic devices directly convert absorbed sunlight into electrical current," said Sampath. "The high-powered devices produce no waste or pollution, and by using the technology developed at Colorado State, the devices can potentially be mass produced at low costs."
In areas without power lines, photovoltaics have long been considered an economical solution for powering small-scale systems such as solar telephones. Recent improvements to the technology are making it a viable alternative to traditional, fossil fuel-based power systems. Photovoltaics are currently being used to power a variety of electronics from satellites to recreational vehicles.
Even where electrical grids exist, photovoltaics are cost effective in Hawaii, some parts of California and many other regions of the world. In areas without power lines, solar cell technology often is the only source of reliable energy and is more cost effective to install than power grids.
The inability to mass produce photovoltaic modules has, in the past, made this type of solar energy expensive or simply not available to the mass public. Manufacturing costs and scarcity of construction materials have prevented large-scale production of the technology.
"Expanding the use of photovoltaics is limited by the lack of manufacturing volume and the difficulty in adding new manufacturing capacity," said Kurt Barth, a research associate at the Materials Engineering Laboratory. "Solar cells must be manufactured like other mass-produced items in order to become available and affordable to the mass public. Once we get to that point, photovoltaics will be one of the most environmentally clean and cost-effective energy sources in the world."
The research group at Colorado State, supported by funding from the National Science Foundation, the Environmental Protection Agency, the Department of Energy and the National Renewable Energy Laboratory, has developed solutions to the mass production limitations.
In addition to making solar cells more effective and efficient, the research team developed a machine that produces three-inch-square solar cells at the rate of one cell every two minutes, an increase of up to 100 times faster that other currently used technologies. The equipment has a low capital cost and, unlike other solar cell production technologies, is fully automated. The raw materials used to produce the cells are industrial byproducts that are inexpensive to buy and commercially available in bulk.
The team of engineers is currently building a larger machine that will make one-foot-square cells, which will be 16 times more powerful. Five to 10 hours of production on the larger machine will make enough cells to power an average house. Linking several cells together has the potential to create larger applications such as supplying power to an entire city.
Since the research and development for the technology has already been completed, capital requirements for these machines are becoming less expensive and many production units could be built to meet market demand in the near future, according to Sampath. These advancements have the potential of reducing the cost of manufacturing photovoltaics to less than $1 per watt of electricity generated, a cost that is competitive with current methods of electricity generation in most parts of the United States and the world.
Scientists estimate the world’s population will reach more than eight billion by the year 2025, and with it an anticipated 80 percent increase in annual global energy production, or the equivalence of about 12 trillion barrels of oil per year.
"As oil, coal, nuclear and natural gas resources decrease and environmental problems associate with the increased burning of fossil fuels increase, the need for and use of renewable energy is anticipated to increase significantly," said Sampath. "We are working to help meet that need in advance."
For more information about photovoltaic research and development at Colorado State, including technical specifications, visit the Web at www.engr.colostate.edu/me/.