See also:

• Photovoltaics History and Timeline


• Solar Cell


• Solar Panel


• Photovoltaic System


• Solar Vehicle


• Economics of PV


• PV Environmental Impacts


• Photovoltaics Pros & Cons


• PV Companies, Industry Associations, Research Institutes

Disadvantages

• Solar electricity is often more expensive than electricity generated by other sources.
• Solar electricity is not available at night and is less available in cloudy weather conditions. Therefore, a storage or complementary power system is required.
• Limited power density: Average daily insolation in the contiguous U.S. is 3-7 kW·h/m²^[79][80][81] and on average lower in Europe.
• Solar cells produce DC which must be converted to AC (using a grid tie inverter) when used in currently existing distribution grids. This incurs an energy loss of 4-12%.^[82]

Advantages

• The 89 petawatts of sunlight reaching the earth's surface is plentiful - almost 6,000 times more - compared to the 15 terawatts of average power consumed by humans.^[83] Additionally, solar electric generation has the highest power density (global mean of 170 W/m²) among renewable energies.^[83]
• Solar power is pollution free during use. Production end wastes and emissions are manageable using existing pollution controls. End-of-use recycling technologies are under development.^[84]
• Facilities can operate with little maintenance or intervention after initial setup.
• Solar electric generation is economically superior where grid connection or fuel transport is difficult, costly or impossible. Examples include satellites, island communities, remote locations and ocean vessels.
• When grid-connected, solar electric generation can displace the highest cost electricity during times of peak demand (in most climatic regions), can reduce grid loading, and can eliminate the need for local battery power for use in times of darkness and high local demand; such application is encouraged by net metering. Time-of-use net metering can be highly favorable to small photovoltaic systems.
• Grid-connected solar electricity can be used locally thus reducing transmission/distribution losses (transmission losses were approximately 7.2% in 1995).^[85]
• Once the initial capital cost of building a solar power plant has been spent, operating costs are extremely low compared to existing power technologies.
• Compared to fossil and nuclear energy sources, very little research-money has been invested in the development of solar cells, so there is much room for improvement. Nevertheless, experimental high efficiency solar cells already have efficiencies of over 40% and efficiencies are rapidly rising while mass production costs are rapidly falling.^[86]

References