The 2014 Intergovernmental Panel on Climate Change report identifies nuclear, wind, solar and hydroelectricity in suitable locations as technologies that can provide electricity with less than 5% of the lifecycle greenhouse gas emissions of coal power.
Hydroelectric power when completed in 1936 was both the world's largest electric-power generating station and the world's largest concrete structure.
Hydroelectric plants have the advantage of being long-lived and many existing plants have operated for more than 100 years. Hydropower is also an extremely flexible technology from the perspective of power grid operation. Large hydropower provides one of the lowest cost options in today's energy market, even compared to
fossil fuels and there are no harmful emissions associated with plant operation. However, there are typically low greenhouse gas emissions with
reservoirs, and possibly high emissions in the tropics. Hydroelectric power is the world's largest low carbon source of electricity, supplying 15.6% of total electricity in 2019.
China is by far the world's largest producer of
hydroelectricity in the world, followed by
Brazil and
Canada. However, there are several significant social and environmental disadvantages of large-scale hydroelectric power systems: dislocation, if people are living where the reservoirs are planned, release of
significant amounts of carbon dioxide and methane during construction and flooding of the reservoir, and disruption of aquatic ecosystems and birdlife. There is a strong consensus now that countries should adopt an integrated approach towards managing water resources, which would involve planning hydropower development in co-operation with other water-using sectors. Nuclear power, in 2010, also provided two thirds of the twenty seven nation
European Union's low-carbon energy, with some EU nations sourcing a large fraction of their electricity from nuclear power; for example
France derives 79% of its electricity from nuclear. As of 2020 nuclear power provided 47% low-carbon power in the EU with countries largely based on nuclear power routinely achieving carbon intensity of 30-60 gCO2eq/kWh. In 2021
United Nations Economic Commission for Europe (UNECE) described nuclear power as important tool to mitigate climate change that has prevented 74
Gt of emissions over the last half century, providing 20% of energy in Europe and 43% of low-carbon energy.
Wind power Solar power concentrates sunlight from a field of heliostats on a central tower. Solar power is the conversion of
sunlight into electricity, either directly using
photovoltaics (PV), or indirectly using
concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the
photoelectric effect. Commercial concentrated solar power plants were first developed in the 1980s. The 354 MW
SEGS CSP installation is the largest solar power plant in the world, located in the
Mojave Desert of California. Other large CSP plants include the
Solnova Solar Power Station (150 MW) and the
Andasol solar power station (150 MW), both in Spain. The over 200 MW
Agua Caliente Solar Project in the United States, and the 214 MW
Charanka Solar Park in India, are the
world's largest photovoltaic plants. Solar power's share of worldwide electricity usage at the end of 2014 was 1%.
Geothermal power Geothermal electricity is
electricity generated from geothermal energy. Technologies in use include dry steam power plants, flash steam power plants and binary cycle power plants. Geothermal electricity generation is used in 24 countries while
geothermal heating is in use in 70 countries. Current worldwide installed capacity is 10,715 megawatts (MW), with the largest capacity in the
United States (3,086 MW),
Philippines, and
Indonesia. Estimates of the electricity generating potential of geothermal energy vary from 35 to 2000 GW.
Tidal power Tidal power is a form of
hydropower that converts the energy of tides into electricity or other useful forms of power. The first large-scale tidal power plant (the
Rance Tidal Power Station) started operation in 1966. Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power.
Carbon capture and storage Carbon capture and storage (CCS) captures carbon dioxide from the
flue gas of power plants or other industry, transporting it to an appropriate location where it can be buried securely in an underground reservoir. Between 1972 and 2017, plans were made to add CCS to enough coal and gas power plants to sequester 171 million tonnes of per year, but by 2021 over 98% of these plans had failed. Cost, the absence of measures to address long-term liability for stored CO2, and limited social acceptability have all contributed to project cancellations. As of 2024, CCS is in operation at only five power plants worldwide. == Outlook and requirements ==