Recent innovations have also made vertical curtain walls and awnings practical because integrated PV modules can replace facade materials, such as granite and architectural glass. With all of its advantages and promise of continued cost reductions, the potential for PV-powered buildings is very great indeed. Japanese and European markets, already under development, hold similar potential. In a stand-alone system, the building has no connection to the utility grid and often relies on a bank of batteries to store power for use at night and during periods of limited sun. With net metering, the utility grid becomes the storage medium, in place of on-site batteries.
Owners benefit from lower system costs and reduced maintenance.
The utility benefits because the PV system produces its surplus at or near the peak of the utility's demand. Cells, Modules, and Arrays Photovoltaic electricity is produced by an array of individual PV modules electrically connected in series and parallel to deliver the desired voltage and current. Each PV module, in turn, is constructed of individual solar cells also connected in series and parallel. Dozens of solar cells are connected together to produce a PV module. The number of cells determines a module's size and power.