<br />Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, rain, tides, waves, and geothermal heat.[3] Although most renewable energy sources are sustainable, some are not. For example, some biomass sources are considered unsustainable at current rates of exploitation.[4)<br />Renewable energy often provides energy for: electricity generation to a grid, air and water heating/cooling, and stand-alone power systems. About 20% of humans' global energy consumption is renewables, including almost 30% of electricity.[6] About 8% of energy consumption is traditional biomass, but this is declining.[7] Over 4% of energy consumption is heat energy from modern renewables, such as solar water heating, and over 6% electricity.[7]<br /><br />Globally there are over 10 million jobs associated with the renewable energy industries, with solar photovoltaics being the largest renewable employer.[8] Renewable energy systems are rapidly becoming more efficient and cheaper and their share of total energy consumption is increasing,with a large majority of worldwide newly installed electricity capacity being renewable.In most countries, photovoltaic solar or onshore wind are the cheapest new-build electricity.<br /><br />Many nations around the world already have renewable energy contributing more than 20% of their energy supply, with some generating over half their electricity from renewables. National renewable energy markets are projected to continue to grow strongly in the 2020s and beyond.A few countries generate all their electricity using renewable energy. Renewable energy resources exist over wide geographical areas, in contrast to fossil fuels, which are concentrated in a limited number of countries. Deployment of renewable energy and energy efficiency technologies is resulting in significant energy security, climate change mitigation, and economic benefits.However renewables are being hindered by hundreds of billions of dollars of fossil fuel subsidies. In international public opinion surveys there is strong support for promoting renewable sources such as solar power and wind power.<br /><br />Renewable energy technology projects are typically large-scale, but they are also suited to rural and remote areas and developing countries, where energy is often crucial in human development. As most of the renewable energy technologies provide electricity, renewable energy is often deployed together with further electrification, which has several benefits: electricity can be converted to heat, can be converted into mechanical energy with high efficiency, and is clean at the point of consumption.In addition, electrification with renewable energy is more efficient and therefore leads to significant reductions in primary energy requirements. In 2021, China accounted for almost half of the increase in renewable electricity in 2021, Norway, known for its production of hydroelectricity, consumed hydro energy worth 45% of its total energy supply.<br /><br />Renewable energy stands in contrast to fossil fuels, which are being used far more quickly than they are being replenished. Renewable energy resources and significant opportunities for energy efficiency exist over wide geographical areas, in contrast to other energy sources, which are concentrated in a limited number of countries. Rapid deployment of renewable energy and energy efficiency, and technological diversification of energy sources, would result in significant energy security and economic benefits.[17] Economically, there has been a decrease in the cost of the technologies behind many of these renewable energy sources, such as solar and wind power.In some cases it will be cheaper to transition to these sources as opposed to continuing to use the current, inefficient, fossil fuels. It would also reduce environmental pollution such as air pollution caused by the burning of fossil fuels, and improve public health, reduce premature mortalities due to pollution and save associated health costs that could amount to trillions of dollars annually.Multiple analyses of decarbonization strategies have found that quantified health benefits can significantly offset the costs of implementing these strategies.Renewable energy sources, that derive their energy from the sun, either directly or indirectly, such as hydro and wind, are expected to be capable of supplying humanity energy for almost another 1 billion years, at which point the predicted increase in heat from the Sun is expected to make the surface of the Earth too hot for liquid water to exist.<br /><br />