Photovoltaic (PV) systems are used to convert energy from the sun into electricity. They are a safe and reliable source of solar electricity that produces no on-site pollution or emissions. PV systems incur few operating costs and can be installed on any kind of building, such as:
- Institutional; or
PV systems fall into two main categories — off-grid and grid-connected. The "grid" refers to the local electric utility's infrastructure that supplies electricity to consumers. Off-grid systems are typically installed in remote locations where no utility grid is available. These systems usually require storage, such as batteries, to store the excess electricity generated by the PV system. Energy can be withdrawn from the batteries when the demand exceeds the PV system electricity production. Grid-connected systems can also include storage technologies, but they generally feed any excess electrical energy production to the grid.
In the built environment, photovoltaic systems can be split into two market segments:
- Building-applied photovoltaics (BAPV), where the PV system is added to an existing building (e.g. conventional rooftop applications); and
- Building-integrated photovoltaics (BIPV), where the PV system can be included as part of building components to become an integral part of the building skin.
For more information on the technical, economic, environmental and social aspects of photovoltaic systems and examples of PV systems around the world, visit the International Energy Agency Photovoltaic Power Systems Program website.