Renewable Generation

The oldest confirmed windmill designs are dated to Iran between 700 and 900 CE. They established mechanical wind harnessing centuries before its conversion to electricity, forming the technological ancestry of modern wind power.

Commenting on the solid-state photovoltaic effect, Siemens argued its practical value lay in the limitless and costless supply of solar energy, which would outlast the world's coal deposits. The remark marks an early recognition that photovoltaics could become a durable electricity source.

An article published in 1911 recognised the long-term importance of solar energy in a world of exhausted natural fuels. It reflected an era of solar engine development that continued until the outbreak of the First World War.

The theory of peak oil appeared in 1956 and supplied an intellectual basis for anticipating the depletion of fossil resources. It later underpinned environmentalist advocacy for renewable energy development.

During the 1970s environmentalists promoted renewable energy both as a replacement for eventually depleted oil and as an escape from oil dependence. The first electricity-generating wind turbines appeared in this period, marking the start of wind as a power-sector technology rather than a mechanical one.

Solar had long been used for heating and cooling, but panels remained too costly for solar farms until around 1980. Crossing that cost threshold opened the way to utility-scale photovoltaic generation.

The 1982 Hesperia plant was the world's first utility-scale solar power station. It demonstrated that photovoltaic generation could be deployed at grid scale rather than only in small installations.

Europe led in creating energy policy supporting renewables in the early 2000s, before the practice spread worldwide. Most countries now have some form of energy policy, and 156 countries have laws regulating the renewable energy sector.

New government spending, regulation and policies helped renewables through the 2008 financial crisis and the Great Recession. The sector's resilience consolidated state support as a structural feature of renewable deployment.

IRENA was formed in 2009 when 75 countries signed its charter, and had grown to 160 member states by April 2019. It became the principal intergovernmental body tracking renewable capacity, costs and finance.

The MIT spin-off stopped scaling its prototype in 2012 because it offered few savings over other routes to making hydrogen from sunlight. The retreat illustrated the difficulty of commercialising emerging solar-to-fuel technologies.

Between 2013 and 2022 installation costs fell by 69% for solar photovoltaics, 33% for onshore wind and 45% for offshore wind. These declines made renewables cost-competitive with fossil generation and drove the surge in deployment.

The 2015 Paris Agreement motivated many countries to develop or improve renewable energy policies. By 2017, 121 countries had adopted some form of renewable energy policy and national targets existed in 176 countries.

Think tank Ember reported that in April 2026 wind and solar combined generated more electricity than gas worldwide over a calendar month for the first time. The milestone marked variable renewables overtaking a major fossil generation source at global scale.

During 2025 renewables accounted for 85.6% of all new electricity generation capacity added worldwide, with solar photovoltaics providing nearly three-quarters of the increase. By the end of that year renewables made up 49.4% of global installed generating capacity.

A 2024 study examined harnessing the Earth's outgoing infrared thermal radiation as an energy source. It concluded that with current and near-future technologies the concept would not be economically competitive.

Recent analyses indicate global solar PV capacity surpassed 1 TW in 2024, supplying roughly 6–7% of world electricity. Total renewable power capacity reached 4,300 GW by the end of that year, with solar accounting for over 60% of annual additions.

Global solar power capacity grew by almost 30% in 2023, driven by falling panel prices and expanded government incentives. Investment in solar and wind reached roughly US$200 billion, a 75% rise on the previous year.

At the 2023 United Nations Climate Change Conference most states committed to tripling global renewable energy capacity by the end of the decade. The pledge became the headline international benchmark for renewable deployment.

The IEA's December 2022 report projected renewable growth of nearly 2,400 GW over 2022–2027, equal to China's entire installed power capacity in 2021. The projection was an 85% acceleration on the previous five years and the agency's largest ever upward revision.

IRENA reported that about 187 GW, or 86%, of renewable capacity added in 2022 had lower costs than fossil-fuelled generation. It also calculated that capacity added since 2000 cut electricity bills by at least $520 billion in 2022.

The EU aimed in 2022 to generate 40% of its electricity from renewables by 2030. By 2025, 47% of EU electricity generation already came from renewable sources.

Scientists mapped areas containing renewable energy materials and estimated their overlap with Key Biodiversity Areas, Remaining Wilderness and Protected Areas. The work documented the land and mining footprint accompanying renewable deployment.

Offshore wind investment rose to US$41 billion between 2019 and 2020, driven mainly by policy incentives in China and expansion in Europe. Global wind capacity grew by 557 GW between 2013 and 2021, with additions rising about 19% a year.

Chinese photovoltaic capacity grew faster than anywhere else between 2016 and 2021, adding 560 GW. The expansion made China the dominant player in solar generation, hosting four of the ten biggest solar stations by 2025.