The key components of a photovoltaic power system are the photovoltaic cells (sometimes also called solar cells) interconnected and encapsulated to form a photovoltaic module (the commercial product), the mounting structure for the module or array, the inverter (essential for grid-connected systems and required for many off-grid systems), the storage battery and charge controller (for off-grid systems only).

Crystalline silicon technologies currently account for most of the overall cell production in the IEA PVPS countries.

Single crystal PV cells are manufactured using a single-crystal growth method and have commercial efficiencies between 15 % and 18 %.

Multicrystalline cells, usually manufactured from a melting and solidification process, are less expensive to produce but are marginally less efficient, with conversion efficiencies around 14 %.

Thin film cells, constructed by depositing extremely thin layers of photovoltaic semi-conductor materials onto a backing material such as glass, stainless steel or plastic, show stable efficiencies in the range of 7 % to 13 %. Thin film materials commercially used are amorphous silicon (a-Si), cadmium telluride (CdTe), and copper-indium-gallium-diselenide (CIGS).

Commercially available thin film modules:

• Are potentially cheaper to manufacture than crystalline cells
• Have a wider customer appeal as design elements due to their homogeneous appearance
• Present disadvantages, such as low-conversion efficiencies and requiring larger areas of PV arrays and more material (cables, support structures) to produce the same amount of electricity

PV technology can be employed in a variety of applications:

Off-grid domestic PV systems:

• Provide electricity to households and villages that are not connected to the utility electricity network (also referred to as the grid)
• Provide electricity for lighting, refrigeration and other low power loads
• Have been installed worldwide
• Are often the most appropriate technology to meet the energy demands of off-grid communities

Off-grid non-domestic PV installations:

• Are used in locations where small amounts of electricity have a high value
• Were the first commercial application for terrestrial PV systems
• Provide power for a wide range of applications, such as telecommunication, water pumping, vaccine refrigeration and navigational aids
• Make PV commercially cost competitive with other small generating sources

Grid-connected distributed PV systems:

• Provide power to grid-connected customers or directly to the electricity network (specifically where that part of the electricity network is configured to supply power to a number of customers rather than to provide a bulk transport function)
• May be on or integrated into the customer's premises, often on the demand side of the electricity meter, on public and commercial buildings, or elsewhere in the built environment

Grid-connected centralized PV systems:

• Perform the functions of centralized power stations
• Supply power that is not associated with a particular electricity customer
• Primarily supply bulk power, rather existing on the electricity network to perform specific functions.