
Solar cells are often electrically connected and encapsulated as a larger module called solar panels. Photovoltaic modules often have a sheet of glass on the top surface, which enables light through however protects the semiconductor wafers from weather conditions. Solar cells are also mostly connected in series as modules, creating an additive voltage. These are also known as Solar PV Panels.

To make practical use of the solar-generated energy, the electricity is most often fed into the electricity grid using inverters; in stand-alone systems, batteries are used to store the energy that is not needed immediately. Solar panels can be used to power or recharge portable devices.
Connecting the solar cells in parallel will develop higher current. Modules are then interconnected, in series or parallel, to create an array with the desired peak DC voltage and current.
The efficiency of a solar panel in the UK may be broken down into reflectance efficiency, conductive efficienc, charge carrier separation efficiency and, thermodynamic efficiency. The overall efficiency is the product of each of these individual entities.

Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power. CSP systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam whilst Solar PV systems convert light into electric current using the photoelectric effect.
Commercial CSP plants were first developed in the 1980s, and the 354 MW SEGS CSP installation is the largest solar power plant in the world and is located in the Mojave Desert.
The early development of solar technologies starting in the 1860s was driven by an expectation fossil fuels would soon become scarce. However development of solar technologies stagnated in the early 20th century in the face of the increasing availability, economy, and utility of coal and petroleum. In 1974 it was estimated that only 6 homes in all of North America were entirely heated or cooled by solar power systems.
The 1973 oil embargo and 1979 energy crisis caused a reorganisation of energy policies around the world and brought renewed attention to developing solar technologies.
Between 1970 and 1983 Solar photovoltaic installations grew rapidly, but falling oil prices in the early 1980s moderated the growth of PV from 1984 to 1996. Since 1997, Solar PV development has accelerated due to supply issues with oil and natural gas, global warming concerns, and the improving economic position of Solar PV relative to other energy technologies
Deployment strategies focused on incentive programs such as the Federal Photovoltaic Utilization Program in the US and the Sunshine Program in Japan.