Solar power is the conversion of energy from sunlight into electricity, either directly using photovoltaics (PV), indirectly using concentrated solar power, or a combination. Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaic cells convert light into an electric current using the photovoltaic effect.

Many industrialized nations have installed significant solar power capacity into their grids to supplement or provide an alternative to conventional energysources while an increasing number of less developed nations have turned to solar to reduce dependence on expensive imported fuels. Long distance transmission allows remote renewable energy resources to displace fossil fuel consumption. Solar power plants use one of two technologies:

• Photovoltaic (PV) systems use solar panels, either on rooftops or in ground-mounted solar
  farms, converting sunlight directly into electric power.

• Concentrated solar power (CSP, also known as "concentrated solar thermal")
  plants use solar thermal energy to make steam, that is thereafter converted into electricity by a turbine.