The next time you turn the lights on at work, you may have the sun to thank for your power. More and more, the world’s most abundant natural resource is generating significant amounts of environmentally friendly electricity for businesses throughout the United States.
The re-emergence of solar energy into the business world’s consciousness comes as more companies realize that photovoltaic (PV) solar panels provide them with the opportunity to generate clean, renewable energy—from the burning of fossil fuels—at a cost that is increasingly competitive. Wal-Mart, American Apparel and La-Z-Boy are just a few of the companies who, in light of this realization, have jumped on the solar energy bandwagon using solar panels to power their businesses.
Additionally, another type of solar energy—solar thermal power—is being viewed as an important source of renewable energy for residential and business customers in the southwestern part of the country. With one new solar thermal power plant in the region already finished and another currently being constructed, thousands of companies and residences in the Southwest can now receive energy from the sun.
Companies are adopting solar power not only because they recognize their responsibility to be good corporate citizens, but also because they realize such early adoption will end up benefiting the bottom line. While the cost of fossil-fuel-generated energy in the United States continues to increase with no end in sight, the efficiencies and technologies behind all aspects of solar power are steadily improving.
For instance, the National Renewable Energy Laboratory (NREL) has reported that by 2020, it expects the cost of energy supplied by solar thermal power plants to be between 6.2 and 4.3 cents per kilowatt hour—costs that are as low as or lower than today’s fossil fuel costs.
Moreover, manufacturing techniques for building PV modules continue to improve, and as the current silicon shortage eases, the cost of PV panels will decrease. By securing knowledge today about how to use solar energy to power their businesses, companies will be better positioned to reap the benefits as the cost of solar technology falls.
The most well-known type of solar power, PV power converts directly into electricity through the use of solar cells. These cells use silicon—the same type of material used in computer chips—to generate a flow of electricity when sunlight shines on them. What happens is that when photons from the sun (or packets of light) collide with the silicon atoms in the cell, electrons are released. These electrons flow into wires connected to the cell, and this electric current is then connected to a facility’s electrical system.
There are two main types of PV cells. One type of PV cell uses silicon crystals placed under a layer of glass to generate electricity. Another type of PV cell is made by spreading a thin film of amorphous silicon between two layers of glass. While less efficient than crystalline solar cells, these thin-film solar cells can be semi-transparent, which offers light and visual transmission, and can be integrated into a building’s curtain wall.
One key advantage to PV power is that it is easily scalable. You can build a small PV system to power a remote cell phone tower, or you can set up a field full of PV panels to power an entire office park. This enables companies to easily secure PV systems that meet their specific energy generation needs. Moreover, PV power’s ability to generate electricity in cloudy conditions and cold environments makes it suitable for companies in all areas of the country. In fact, some businesses in the Northeast see PV power as the perfect way to convert former industrial waste sites from “brownfields” into environmentally friendly—and revenue-generating—“greenfields.”
Meeting a Need
While PV systems are the most flexible and scalable type of solar power available today, solar thermal power plants have the greatest potential for the generation of power on a large, utility-based scale. Solar thermal power plants can generate enough electricity to power thousands of homes at a time, thus reducing utilities’ need to use power plants that burn carbon-dioxide-emitting coal, natural gas and fossil fuels to meet our energy needs.
Unlike PV power, solar thermal power does not directly convert solar radiation into electricity, but does it indirectly, using heat. For instance, one type of solar thermal power plant, called a parabolic trough power plant, uses parabolic mirrors to focus solar radiation onto solar receiver tubes carrying a Heat Transfer Fluid (HTF). This HTF is heated to a temperature of 750 degrees Fahrenheit, and then used to turn water into steam, which drives a turbine to generate electricity. Currently more efficient than PV power, the only downside of solar thermal power plants is that they require a great deal of direct sunlight, making them only suitable for areas in the world’s Sunbelt, such as the American Southwest.
Although solar thermal power plants have existed for several decades in the SEGS solar thermal fields in California, a renaissance is just now taking place thanks to improving technologies from leading companies like SCHOTT, and an increased awareness of the importance of domestically produced electricity and the environmental benefits of solar power.
For instance, the Saguaro solar-thermal power-plant, located in the Arizona desert between Phoenix and Tucson, went online in April. In addition, the 64-megawatt Nevada Solar One power plant is being built near Las Vegas, and other solar thermal projects are being developed elsewhere in the Southwest. Some companies in energy-intensive businesses are even considering the development of their own solar thermal power plants to power their operations.
One of the major advantages of solar thermal power for businesses is the ease at which they can tap into this power. Since the plants are connected to the grid, businesses can simply sign up for their utilities’ green-energy plant to begin using the power generated by these plants. While such electricity might cost slightly more today, it offers companies the ability to brand themselves as “powered by clean electricity,” an important differentiating factor for today’s “green” consumer.
Brian Lynch is with SCHOTT North America, Inc.