What Is Solar Energy?
Solar energy is the radiation from the sun that reaches the earth. Using photovoltaic cells made from silicon alloys, sunlight can be converted into other forms of energy, such as heat and electricity. Solar cells can convert up to 22 percent of sunlight into electricity. Steam generators using thermal collectors to heat a working fluid can also produce electricity.
Solar thermal energy is currently used for heating water for domestic use and for heating building space. Flat-plate solar energy collectors with a fixed orientation are generally used in these cases. Most consist of a flat-plate absorber to intercept and absorb solar energy; a transparent cover to allow solar energy to pass through; a heat-transport fluid flowing through tubes to remove heat from the absorber; and a heat-insulating backing. Solar thermal systems are also being used for utility-scale power generation plants in California and other states.
What Are the Benefits?
Since early 2005, energy prices have increased in the United States, which has fueled interest in alternatives such as solar energy. Using solar power can help alleviate capacity problems on local utility systems, especially during peak electricity demand periods. It also reduces greenhouse gas emissions and fuel consumption by displacing electricity generated by fossil-fuel power plants.
What Chevron Is Doing
Chevron is investing across the energy spectrum to develop energy sources for future generations by expanding the capabilities of today's alternative and renewable energy technologies. Chevron has invested more than $2 billion on developing alternative and renewable energy technologies and in energy efficiency services since 2002. We expect to spend more than $2.5 billion in these areas between 2007 and 2009.
Examples of recent Chevron projects that use solar power include the largest solar installation at an institution of higher learning in North America, at the Contra Costa Community College District in California. Chevron Energy Solutions, a Chevron subsidiary, is installing a 3.2-megawatt system comprising photovoltaic panels mounted on 34 parking canopies at three campuses. The project is the highlight of a multifacility energy-efficiency and solar program that is expected to save the district more than $70 million over 25 years.
Forty miles from Bakersfield, California, in the San Joaquin Valley, Chevron Energy Solutions, in collaboration with United Solar Systems Corporation, a subsidiary of Energy Conversion Devices, Inc., Michigan, completed the installation of the first photovoltaic facility in California to help power oil-field operations. Called Solarmine, the 500-kilowatt, six-acre facility is one of the largest arrays of flexible, amorphous-silicon solar technology in the world. A key example of how the solar technology business has matured, the facility uses 4,800 flexible, current-producing solar panels mounted on metal frames. The amorphous silicon technology-based panels can withstand direct impact and puncture without erosion of their power-generating ability and can be used in the commercial sector for commercial roofing.
On the U.S. East Coast, Chevron Energy Solutions collaborated with the University of Buffalo in the installation of photovoltaic panels on the roof of the university's Norton Hall, which houses administrative, classroom and research spaces. The installation resulted in the largest solar array on any building in western New York state.
Chevron Energy Solutions recently completed the largest solar power and energy-efficiency project for the U.S. Postal Service (USPS) at its mail processing center in Oakland, California. The project, which included the installation of energy-efficient equipment, is reducing the facility's power purchases by more than a third. The 910-kilowatt solar power system spans a rooftop area nearly the size of two football fields and will help meet electric demand during peak periods.
The improvements at the facility, the largest of its kind in Northern California, will lower total annual electricity purchases by almost 11 million kilowatt hours. This reduced demand for power translates to 7,400 fewer tons of carbon dioxide emitted by the local electric utility annually — the same volume of carbon dioxide that would be absorbed by planting more than 2,000 acres of trees.
Chevron Energy Solutions also installed two solar technology systems and a hydrogen fuel cell generation system, along with efficiency improvements, at two USPS processing centers in San Francisco and a solar parking structure and efficiency project at the USPS mail center in West Sacramento. Along with projects at other mail facilities in Northern California, these improvements will save the USPS more than $2 million in annual energy costs.
Updated: March 2008