Renewable energy

Lore & Background

Renewable energy, also termed green energy, is derived from natural resources that are replenished on a human timescale. The most common types are solar energy, wind power, and hydropower, with bioenergy and geothermal power also significant in certain countries. Installations vary widely in scale, from small units to large facilities, and are suitable for both urban and rural settings. A key characteristic is that renewable energy is often paired with further electrification, allowing electricity to efficiently power heating, cooling, and vehicles while remaining clean at the point of use. Sources are divided into variable types—such as wind and solar, which fluctuate—and controllable types, including dammed hydroelectricity, bioenergy, and geothermal power. For a source to be considered renewable, it must be endless; nuclear power is excluded because it relies on non-renewable uranium fuel. Over the past four decades, renewable systems have become markedly more efficient and affordable. By 2025, renewables accounted for over 30% of global electricity generation, with projections reaching over 45% by 2030. Many countries now source more than 20% of their total energy from renewables, and some generate over half or all of their electricity this way. The primary motivation for adopting renewables is reducing greenhouse gas emissions that drive climate change; they also produce far less air pollution, improving public health, and are quieter than fossil fuels. However, deployment faces obstacles including fossil fuel subsidies, lobbying by incumbent providers, local opposition to land use, and environmental damage from mineral extraction required for many technologies.

Reader's Guide

Renewable energy is central to addressing climate change, as its main motivation is to reduce greenhouse gas emissions. The International Energy Agency estimates that to achieve net zero emissions by 2050, 90% of global electricity will need to be generated by renewables. However, the current pace of renewable expansion remains far from this required rate globally, including in major economies such as the G7 and the EU. Renewable energy also brings health benefits by reducing air pollution, with potential worldwide savings in health care costs estimated at trillions of dollars annually. It is more evenly distributed around the world than fossil fuels. Deployment still faces obstacles, including fossil fuel subsidies, lobbying by incumbent power providers, local opposition to land use, and environmental damage from mineral extraction. Solar and wind are intermittent energy sources, requiring energy storage, demand response, or grid improvements. Pumped-storage hydroelectricity accounts for more than 85% of all grid power storage, while batteries and green hydrogen are increasingly used. The European Union aimed in 2022 to generate 40% of its electricity from renewables by the same year, and by 2025, 47% of EU electricity generation was by renewables.

Did You Know?

• Renewable energy grew from 20% to 28% of the global electricity supply from 2011 to 2021.
• Pumped-storage hydroelectricity accounts for more than 85% of all grid power storage.
• The International Energy Agency estimates that to achieve net zero emissions by 2050, 90% of global electricity will need to be generated by renewables.
• Some consider nuclear power a renewable source, but this is controversial as it requires mining uranium, a nonrenewable resource.