Existing comment:
Photovoltaics (Solar Energy)
To demonstrate the practical use of solar energy technology in an urban setting, two photovoltaic arrays are permanently installed to serve the park. The first, main array is installed at the base of the south wall of the adjacent Department of energy headquarters building. The second array is installed on the sloping top of the framework that holds this sign. These two arrays consist of twenty solar modules. Together they provide 5,300 kWh annually or about 63% of the annual lighting load of this park.
The basic building block of a photovoltaic system is the solar "cell." This device can be made from various semiconductor materials which are treated with special additives that cause the device to become sensitive to light. When photons (particles of energy in sunlight) hit the surface of the solar cell, electrons (particles of energy in atoms) are released, generating a flow of electricity. To complete the device, conductive layers are added to the top and bottom of the solar cell to collect the electricity and carry it to the "load" or the system to be powered. Solar cells come in many shapes and sizes. A diagram of a typical solar cell is shown at right.
Typically, cells are connected together to provide practical electrical voltage and power output levels. This group of cells is then packaged in a special protective enclosure called a "module." The voltage and power outputs of the module depend on the size and number of cells used. Several modules are connected together to form an "array."
Special Thanks:
Secretary Hazel R. O'Leary and the U.S. Department of Energy would like to thank many organizations, individuals, and companies for making this whole effort possible in such a short amount of time.
Thanks to the National Capital Planning Commission, the Commission of Fine Arts, and the Interagency National Mall Roads Workgroup for assisting us with approvals and for enthusiastically supporting this project. Thanks to Paul Spaulding and the General Services Administration for the beautiful design of the park; Jason Harrington and Art Hill with the Department of Transportation – Federal Highway Administration and Gary Burch, Don Gofreddi, and Joe Mathis from the District of Columbia Department of Public Works for fostering the Federal and local partnership that resulted in funding and construction of the park; and Fort Myer Construction Company for constructing the park.
The U.S. Department of Energy would also like to thank John Thornton and the National Renewable Energy Laboratory for the design of the photovoltaic system; Applied Power Corporation for the construction of the photovoltaic system; and General Public Utilities for their financial assistance in implementing the project. Last but not least, the Secretary thanks Arch Durham, Dan Reicher, James Rannels, Linda Sye, and Cherylynne Williams, the project manager, for conceiving of and coordinating the project! |