Photovoltaic (PV) cells convert light directly into electricity, these are often referred to as solar modules or solar panels when many cells are combined. The electricity created by photovoltaic cells can be used for anything that uses electricity, including to power buildings and all their components. PV installed on buildings must be converted to AC power by an inverter before tying into the building power. Most buildings in California utilizing PV power are grid-intertied as well. The inverters today can safely tie into the utility grid. Grid-tied buildings with PV produce power during the sunlit hours, which can be sent back to the grid if producing more than the building uses. The excess power sent back will turn the electric meter backwards and is credited to the sites annual electric needs. When the PV system is insufficient to supply all the buildings power, the excess is drawn from the grid. In this sense the grid acts as the battery system. This allows a site to reap the benefits of PV without having to supply the full load of the building. The drawback is that if there is a utility blackout, the system will shut down for safety precautions. There are inverters available that can grid-tie and provide battery backup in cases of blackouts.

Photovoltaic modules are typically warranted to function 20-25 years, with life expectancies over 35 years with virtually no maintenance and no moving parts. Tracking systems are available that can increase the production of the system up to 40% but take up more space and may require maintenance. There are several different options for integrating PV arrays into a building, the most common method is through mounting on a roof or parking structure. Arrays on a roof may be with or without penetrations for mechanical security. The most common types of PV modules is monocrystalline and polycrystalline. Other types which can integrate into buildings easily are amorphous PV cells which can be flexible and blend in flat against a roof, adhering directly to the surface. These are ideal for metal seamed roofs. A less common type can perform as a translucent glass surface and incorporate directly into the building facade. This translucent type is more expensive but provides power while serving as the buildings glass and shading devices.