Renewable energy, also called green energy, is energy made from natural resources that are naturally replaced over time. The most common types of renewable energy are solar energy, wind power, and hydropower. Bioenergy and geothermal power are also important in some countries. Renewable energy systems can be large or small and work well in both city and country areas. Renewable energy is often used with electricity systems. This helps move heat and power vehicles efficiently and produces no pollution when used. Renewable energy sources that change a lot, like wind and solar power, are called variable. In contrast, sources that can be controlled, such as dammed hydroelectricity, bioenergy, or geothermal power, are called controllable.

Over the past 30 years, renewable energy systems have become more efficient and less expensive. Most new electricity systems added worldwide are now renewable. Solar and wind power have become much cheaper in the last 10 years, making them more competitive with traditional fossil fuels. In some places, solar or wind power is the cheapest way to generate new electricity. From 2011 to 2021, renewable energy grew from 20% to 28% of the world’s electricity supply. Power from the sun and wind made up most of this increase, growing from 2% to 10%. Use of fossil fuels dropped from 68% to 62%. In 2024, renewables provided over 30% of global electricity, and they are expected to reach over 45% by 2030. Many countries already use renewables for more than 20% of their total energy, with some countries using over half or even all of their electricity from renewable sources.

The main reason to use renewable energy instead of fossil fuels is to reduce greenhouse gas emissions, which cause climate change. Renewable energy sources create much less pollution than fossil fuels. They also make less air pollution, improve public health, and are quieter. The International Energy Agency says that to reach net zero emissions by 2050, 90% of the world’s electricity must come from renewable sources. However, the current rate of renewable energy growth is not fast enough to meet this goal, even in wealthy countries like those in the G7 and the European Union.

Using renewable energy still faces challenges, including support for fossil fuels, efforts by companies that rely on traditional energy to oppose changes, and resistance from people who do not want land used for renewable projects. Like all mining, getting the minerals needed for renewable energy technologies can harm the environment.

Some people consider nuclear power a renewable energy source, but this is debated because nuclear energy requires uranium, a resource that is not naturally replaced over time.

Overview

Renewable energy comes from natural processes that happen regularly, such as sunlight, wind, water, heat from the Earth, and organic materials. The International Energy Agency describes it as energy from natural processes that are replaced faster than they are used. The main types of renewable energy include solar power, wind power, hydroelectricity, geothermal energy, and biomass. Renewable energy is often used instead of traditional fuels in four areas: making electricity, heating water and homes, transportation, and providing energy to areas without a power grid.

Although most renewable energy sources produce far fewer carbon emissions than fossil fuels, renewable energy is not the same as low-carbon energy. Some non-renewable sources, like nuclear power, produce almost no emissions. However, some renewable sources, such as burning biomass without planting new plants, can be very carbon-heavy. Renewable energy is also different from sustainable energy, which focuses on the long-term impact of energy sources on future generations. For example, using biomass can sometimes lead to harmful deforestation.

To reduce climate change, many countries have pledged to reach net zero greenhouse gas emissions. This means reducing fossil fuel use and replacing it with energy sources that produce fewer emissions. This process, called "low-carbon substitutions," needs to happen faster to reduce climate risks. At the 2023 United Nations Climate Change Conference, about three-quarters of the world’s countries set a goal to triple renewable energy capacity by 2030. The European Union plans to generate 40% of its electricity from renewable sources by 2030.

Renewable energy is more evenly spread across the globe than fossil fuels, which are found in only a few countries. It also improves health by reducing air pollution from burning fossil fuels. Studies suggest that using renewable energy could save trillions of dollars in healthcare costs each year.

The two most important renewable energy sources, solar and wind, are intermittent, meaning they are not always available. This leads to lower energy production compared to fossil fuel or nuclear power plants, which can provide energy consistently. Solar energy is only captured during the day and works best when there are no clouds. Wind energy can change a lot from day to day or even month to month. This makes it harder to replace fossil fuels because energy demand may not match what renewable sources can provide.

In the short to medium term, some gas-fired power plants or other reliable energy sources may need to stay ready until better storage, grid improvements, or stable energy sources are available. In the long term, energy storage is important for managing the unpredictable nature of renewable energy. Using a mix of renewable sources and smart grids can help balance energy supply and demand.

Connecting the power generation sector with other sectors, like transportation, industry, and buildings, can improve flexibility. For example, electric vehicles can be charged and even send energy back to the grid. Industries can use hydrogen made through electrolysis, and buildings can store heat for heating and cooling.

Building extra wind and solar power capacity can help ensure enough electricity is available even during poor weather. However, during good weather, too much energy might be produced if it cannot be used or stored, so some energy may need to be reduced.

Electrical energy storage includes methods to save energy when production is high and return it to the grid when production is low. Pumped-storage hydroelectricity is the most common type of grid storage, making up over 85% of all storage. Batteries are becoming more common for storing energy and supporting the grid. Green hydrogen is a cost-effective option for long-term storage compared to batteries or pumped hydroelectricity.

Solar and wind power are often used in distributed generation systems, which have both benefits and risks. A major risk is that 90% of supply chains for solar panels are controlled by one country, China. Large-scale use of solar inverters with remote control systems can create security risks, such as hacking, which could disable millions of solar panels and cause major power outages. Similar risks exist for wind farms. The European NIS2 directive helps address these issues by expanding cybersecurity rules to energy generation.

In 2024, global solar photovoltaic capacity reached over 1 terawatt, providing about 6–7% of the world’s electricity. Renewable energy systems are also becoming more vulnerable to extreme weather linked to climate change, such as heatwaves, wildfires, and storms. Solar farms may produce less energy during heat or smoke, and wind turbines may need to stop during strong winds or face damage from ice or waves. These challenges are causing governments and grid operators to strengthen infrastructure and create emergency plans to keep energy supplies reliable.

Mainstream technologies

In 2022, solar power produced about 1.3 terrawatt-hours (TWh) of electricity worldwide, which is 4.6% of the world's total electricity. Most of this increase happened after 2010. Solar energy can be used anywhere with sunlight, but how much energy is collected depends on weather, location, and the time of day.

There are two main ways to use solar energy: solar thermal, which turns sunlight into heat, and photovoltaics (PV), which turns sunlight into electricity. PV is used more widely, making up about two-thirds of the world's solar energy capacity in 2022. PV is also growing faster, with 170 gigawatts (GW) of new PV systems added in 2021, compared to 25 GW of solar thermal systems.

Passive solar refers to building designs that use sunlight to help heat spaces. Examples include using solar chimneys, orienting buildings to face the sun, using materials that store heat, and creating spaces that allow air to move naturally.

From 2020 to 2022, investments in solar technology nearly doubled, from USD 162 billion to USD 308 billion. This growth was driven by lower costs and better technology, especially in PV systems, which made up 90% of these investments. China and the United States received most of these investments, together accounting for about half of all solar investments since 2013. Growth in China, the United States, and Vietnam helped offset declines in Japan and India due to policy changes and the effects of the COVID-19 pandemic. Between 2013 and 2021, the world added 714 GW of solar PV and concentrated solar power (CSP) capacity. In 2021, large-scale solar heating projects increased, especially in China, Europe, Turkey, and Mexico. In 2023, global solar power capacity grew by nearly 30%, helped by lower prices for solar panels and more government support.

A photovoltaic (PV) system uses solar cells in panels to convert light into electricity through the photoelectric effect. PV systems can be small, like those on homes or businesses, or large, like power plants. Solar panels on a home can supply power only to that home or, if connected to a power grid, can join millions of other panels.

The first large solar power plant was built in 1982 in Hesperia, California, by ARCO. It was not profitable and was sold eight years later. Over time, PV cells became more efficient and less expensive. Since 2010, PV use has grown rapidly. Global solar capacity increased from 230 GW in 2015 to 890 GW in 2021. China added 560 GW of PV capacity between 2016 and 2021, more than all advanced countries combined. In 2025, four of the ten largest solar power plants were in China, including the largest, the Talatan Solar Park.

Solar panels are recycled to reduce waste and recover materials that would otherwise be mined. However, this process is still small and needs improvement.

Unlike PV systems, which make electricity directly, solar thermal systems use mirrors or lenses to focus sunlight onto a receiver, which heats water. The heated water can be used in homes or to generate electricity by turning water into steam to power a turbine. However, this method is more expensive, so it is used less often.

Floatovoltaics are solar panels that float on water. Benefits include better efficiency and less land use, but they may cost more to build.

Agrivoltaics uses the same land for both solar panels and farming. This can lower land costs and help crops grow better by reducing heat and water loss. However, crops must be able to grow in shaded areas, such as Polka Dot Plants, Pineapple Sage, and Begonias. Careful planning and crop choices are needed for this method to work well.

Humans have used wind energy since at least 3500 BC. Before the 20th century, wind powered ships, windmills, and water pumps. Today, wind energy is mainly used to generate electricity with wind turbines. Modern wind turbines can produce between 600 kW and 9 MW of power. The amount of power a turbine can make depends on wind speed, with faster winds producing more power. Areas with strong, steady winds, like offshore and high places, are best for wind farms.

In 2015, wind energy met nearly 4% of the world's electricity needs, with 63 GW of new wind power added. Wind energy was the leading source of new power in Europe, the United States, and Canada, and the second-largest in China. In Denmark, wind energy met more than 40% of its electricity needs, while Ireland, Portugal, and Spain each met nearly 20%.

Wind energy has the potential to provide five times the world's current energy use or 40 times current electricity needs, if all challenges are solved. This would require large areas with strong winds, especially offshore, and new types of wind turbines. Offshore wind can produce more energy than land-based turbines because wind speeds are about 90% higher there.

In 2020, investments in wind energy reached USD 161 billion, with onshore wind making up 80% of investments from 2013 to 2022. Offshore wind investments nearly doubled to USD 41 billion between 2019 and 2020, driven by policies in China and growth in Europe. Global wind power capacity increased by 557 GW between 2013 and 2021, growing by an average of 19% each year.

Water is much denser than air, so even slow-moving water, like streams or ocean waves, can produce energy. Water can generate electricity with about 90% efficiency, the highest among renewable energy sources. Water energy includes:

• Hydroelectric power: Large dams and reservoirs, like the Three Gorges Dam in China and the Itaipu Dam in Brazil and Paraguay, are still common in developing countries.
• Small hydro systems: Smaller hydroelectric installations are also used.

Emerging technologies

There are other renewable energy technologies that are still being tested, such as improved geothermal systems, concentrated solar power, cellulosic ethanol, piezoelectricity, and marine energy. These technologies are not yet widely used or have limited commercial use. Some may have potential similar to other renewable energy sources, but they need more research, development, and engineering to become practical.

Improved geothermal systems (EGS) are a new way to generate geothermal power that does not need natural hot water or steam. Most underground heat is trapped in solid rocks, not in water. EGS uses a process called hydraulic fracturing to break rocks apart and release heat, which is then captured by pumping water underground. This process is sometimes called "hot dry rock" (HDR). Unlike traditional geothermal energy, EGS could work almost anywhere, depending on the cost of drilling. So far, EGS projects have mostly been limited to small test plants because drilling is expensive.

Sand batteries are large tanks filled with soapstone that store heat. Extra heat from renewable energy sources is sent into the tank, and later, the stored heat is released as boiling water, steam, or warm air. Finland is using this technology in Pornainen, where a 1MW sand battery built by Polar Night Energy can store up to 100 MWh of energy. This system started working in 2025.

Piezoelectricity is the process of converting mechanical stress or vibrations, such as those from walking or moving, into electrical energy without using fuel. Piezotronics combines piezoelectric materials with semiconductors to control how electricity moves. Since the invention of nanogenerators, the efficiency of capturing small amounts of energy has improved. For example, nanogenerators use piezoelectric nanowires. When these wires bend or compress, the movement shifts ions inside the material, creating a charge imbalance. This imbalance produces electricity that can power small sensors. Piezoelectric microelectromechanical systems (piezoMEMS), like devices for medical implants or drug delivery, are important for both medical use and energy collection. Components like piezoelectric resonators and quartz oscillators help control the frequency of electrical circuits.

Marine energy, also called ocean energy, comes from ocean waves, tides, salinity differences, and temperature differences. Technologies to capture this energy include wave power, marine current power, and tidal power. Reverse electrodialysis (RED) is a method that generates electricity by mixing fresh water and salt water in large cells. Most marine energy technologies are still in early stages and not used widely. Tidal energy is the most developed, but it is not yet widely used. The largest tidal power station is on Sihwa Lake in South Korea, which produces about 550 gigawatt-hours of electricity each year.

Earth emits about 10 watts of infrared heat that travels into space. Solar energy reaches Earth's surface and atmosphere, creating heat. Scientists are studying ways to convert this energy flow into electricity using devices like emissive energy harvesters or thermoradiative diodes. This technology could work at night.

Producing liquid fuels from algae that are rich in oil is being researched. Scientists are testing different types of microalgae in open or closed systems, including setups on unused land or deserts.

There have been many ideas for space-based solar power, where large satellites with solar panels would send energy back to Earth using microwaves. A 2024 study by NASA found that this idea is not economically practical with current or near-future technology.

Collecting static electricity from water droplets on metal surfaces is an experimental technology. It could be helpful in low-income countries where the air is usually over 60% humidity.

Breeder reactors can extract nearly all the energy from uranium or thorium, using much less fuel than traditional reactors. This reduces the need for mining and lowers radioactive waste. If uranium can be extracted from seawater, breeder reactors could provide enough energy for billions of years. These reactors could make nuclear energy act like a renewable resource.

Artificial photosynthesis uses nanotechnology to store solar energy in chemical bonds by splitting water into hydrogen and then using carbon dioxide to create methanol. Scientists are working to design systems that use more of the sun's energy and are made from safe, affordable materials. However, progress is slow, and some projects, like one by Sun Catalytix, have paused because they are not cost-effective enough.

Recent research shows that artificial photosynthesis could help create dense, carbon-based fuels for transportation, like planes and ships. These fuels could reduce reliance on fossil fuels if made from sunlight, water, and carbon dioxide. However, challenges remain, such as creating efficient catalysts and addressing public concerns about land use.

Comparison of the theoretical and practical potentials of different renewable energy technologies

In 2019, the world used about 65 petawatt-hours (PWh) of energy each year, or 65,000 terawatt-hours (TWh) annually.

A study reviewed by experts in 2023 found that the maximum energy that can be produced using large-scale solar photovoltaic (PV), concentrated solar power, onshore wind, and offshore wind each exceeds 100 PWh per year. This means each of these energy sources could, in theory, meet the world’s total energy needs.

For solar PV alone, the technical potential is over 5,800 PWh per year using current technology. This is about 89 times the world’s current energy demand. If only 2% of this solar energy were used, it could, in principle, meet the world’s energy needs.

For onshore and offshore wind combined, the technical potential is nearly 900 PWh per year, or 900,000,000,000,000 kWh per year. This is about 14 times the world’s current energy demand. However, wind energy is not always available and cannot be collected from all areas of the Earth.

Using current technology, solar and wind energy together can capture at least 6,700 PWh per year. This is more than 100 times the world’s current energy demand.

The gross theoretical potential for energy from all sources is about 52 PWh per year, spread across 11.8 million possible locations worldwide. This equals about 33% of the world’s annual energy needs.

Conventional geothermal energy has a technical potential above 10 PWh per year. Advanced geothermal systems (EGS) could produce about 4,000 PWh of energy annually, which is enough to meet global electricity demand 140 times over. This makes geothermal energy the second-largest renewable energy source after solar PV.

Rooftop solar PV, wave energy, tidal energy, ocean thermal energy conversion (OTEC), and salinity gradient energy each have technical potentials above 1 PWh, 10 PWh, and 0.1 PWh per year, respectively.

When considering all renewable energy sources, the global technical potential ranges from 164 to 27,200 PWh per year. This is 6.6 to 1,101 times the world’s electricity use in 2021, which was 24.7 PWh per year.

Studies on the economic potential of renewable energy show that it is greater than current and near-future electricity demand. About 60% of the world’s solar energy and 15% of its wind energy are already economically competitive compared to local fossil fuel energy production.

Market and industry trends

Most new renewable energy sources are solar, followed by wind, then hydro, and then bioenergy. Investments in renewables, especially solar, often create more jobs than investments in coal, gas, or oil. As of 2020, renewables employed about 12 million people worldwide, with solar photovoltaics (PV) being the largest employer, providing jobs for nearly 4 million people. However, as of February 2024, the number of workers trained for solar energy is much lower than the demand for these jobs, as universities still train more people for fossil fuel industries than for renewable energy.

In 2021, China added nearly half of the world’s new renewable electricity. A total of 3,146 gigawatts of renewable energy was installed in 135 countries, and 156 countries have laws that regulate renewable energy.

According to the International Renewable Energy Agency, in 2025, renewables accounted for 85.6% of new electricity generation globally, with solar PV contributing nearly three-quarters of this growth. By the end of 2025, renewables made up 49.4% of the world’s total electricity-generating capacity.

In 2020, over 10 million jobs were linked to renewable energy, with solar PV being the largest employer. Between 2019 and 2022, the clean energy sector added about 4.7 million jobs worldwide, reaching a total of 35 million jobs by 2022.

Some studies suggest that switching completely to renewable energy in all areas—such as power, heat, transport, and industry—is possible and cost-effective.

One way to reduce carbon emissions in transportation is by using electric vehicles (EVs). However, even with EVs and biofuels like biojet, less than 4% of transport energy comes from renewables. Hydrogen fuel cells are sometimes used for heavy transport, and electrofuels may become more important for sectors like aviation and shipping in the future.

Solar water heating systems contribute significantly to renewable heat, especially in China, which has 70% of the world’s total (180 gigawatts thermal). Most of these systems are installed in multi-family buildings and provide hot water for about 50 to 60 million households in China. Globally, solar water heating systems meet the hot water needs of over 70 million households.

Heat pumps provide heating and cooling, help balance electricity use, and are becoming more important. About 10% of heating and cooling energy comes from renewables.

The International Renewable Energy Agency (IRENA) reported that in 2022, about 86% (187 gigawatts) of new renewable energy capacity added had lower costs than electricity from fossil fuels. This capacity also saved at least $520 billion in electricity costs worldwide in 2022. In non-OECD countries, the savings from these projects could reduce costs by up to $580 billion over their lifetimes.

In 2018, a review of studies found that holding greenhouse gas (GHG) emitters responsible for climate change damages could encourage the use of renewable energy.

Between 2010 and 2019, global investment in renewable energy (excluding large hydropower) reached $2.7 trillion. China contributed the most, with $818 billion, followed by the United States ($392.3 billion), Japan ($210.9 billion), Germany ($183.4 billion), and the United Kingdom ($126.5 billion). This was more than three to four times the investment in the previous decade (2000–2009).

By 2022, about 28% of the world’s electricity came from renewables, up from 19% in 1990. By the end of 2024, global renewable power capacity reached 4,300 gigawatts, with solar PV making up over 60% of new installations.

A December 2022 report by the International Energy Agency (IEA) predicted that renewables would grow by 2,400 gigawatts between 2022 and 2027, equal to China’s total power capacity in 2021. This growth is 85% faster than the previous five years and 30% higher than the IEA’s 2021 forecast. Renewables are expected to provide over 90% of global electricity expansion during this period. To reach net zero emissions by 2050, the IEA says 90% of electricity must come from renewables.

In June 2022, IEA Executive Director Fatih Birol said countries should invest more in renewables to lower energy costs, improve energy security, and meet climate goals.

The EU’s REPowerEU plan, aimed at reducing dependence on Russian fossil fuels, is expected to promote green hydrogen production.

After a transition period, renewable energy is expected to supply most of the world’s energy. In 2018, a risk management firm predicted that by 2050, fossil fuels and non-fossil energy sources would each make up about half of the world’s energy mix.

Middle Eastern countries are planning to reduce their reliance on fossil fuels. By 2050, green energy projects in the region are expected to supply 26% of their energy needs, reducing emissions by 1.1 gigatonnes of CO₂ per year.

Major renewable energy projects in the Middle East include:
– Mohammed bin Rashid Al Maktoum Solar Park in Dubai, UAE
– Shuaibah Two Solar Facility in Mecca Province, Saudi Arabia
– NEOM Green Hydrogen Project in NEOM, Saudi Arabia
– Gulf of Suez Wind Power Project in Suez, Egypt
– Al-Ajban Solar Park in Abu Dhabi, UAE

In 2014, the WWF and World Resources Institute discussed renewable energy goals with major U.S. companies. These companies identified key principles for expanding renewable energy use, such as having choices between suppliers, competitive pricing, long-term contracts, access to financing, and collaboration.

In 2020, UK data showed that renewables met 3.4% of transport energy demand (mainly from biofuels) and over 20% of energy demand from commercial and industrial sectors.

In some areas, households can choose to buy renewable energy through green energy programs.

Renewable energy is becoming a key alternative to fossil fuels in developing countries, as these nations expand their energy supplies and address energy shortages. Before 2015, renewable energy was often seen as too expensive for developing countries. However, since 2015, investment in non-hydro renewables has been higher in developing countries than in developed ones. In 2019, developing countries accounted for 54% of global renewable energy investment. The International Energy Agency predicts that renewables will provide most of the energy growth in Africa, Central and South America, and 42% of growth in China by 203

Policy

Policies that support renewable energy have been important in helping it grow. Europe led the way in creating energy policies in the early 2000s, but now most countries worldwide have some kind of energy policy.

The International Renewable Energy Agency (IRENA) is an organization formed by governments to help countries use more renewable energy. IRENA gives advice on policies, helps countries build skills, and shares technology. It was created in 2009, with 75 countries joining at first. By April 2019, 160 countries were members. The former United Nations Secretary-General Ban Ki-moon said renewable energy can help the poorest countries become more prosperous.

The 2015 Paris Agreement on climate change encouraged many countries to create or improve their renewable energy policies. In 2017, 121 countries had some type of renewable energy policy. That year, 176 countries had national goals for renewable energy. Many countries also have policies at the state, provincial, and local levels. Some public utilities help plan or install energy improvements for homes.

Many governments have created green banks. A green bank is a financial institution partly run by the government that uses public money to attract private investment in clean energy. These banks use different financial tools to help overcome challenges that slow the use of clean energy.

Renewable energy policies can be grouped by sectors like agriculture, transportation, buildings, and industry. The European Green Deal aims to achieve climate neutrality (net zero emissions) by 2050. To meet this goal, the European Union plans to reduce greenhouse gas emissions from its energy system to zero by 2050.

Finance

The International Renewable Energy Agency (IRENA) 2023 report on renewable energy finance shows that investments in renewable energy have grown steadily since 2018. In 2020, investments reached USD 348 billion, which was a 5.6% increase from 2019. In 2021, investments rose to USD 430 billion, a 24% increase from 2020. By 2022, investments reached USD 499 billion, a 16% increase from 2021. This growth is due to greater awareness of how renewable energy helps reduce climate change and improve energy security, as well as increased interest from investors in alternatives to fossil fuels. Policies like feed-in tariffs in China and Vietnam have played a major role in increasing the use of renewable energy. Between 2013 and 2022, the cost to install solar photovoltaic (PV), onshore wind, and offshore wind energy dropped by 69%, 33%, and 45%, respectively, making these technologies more affordable.

From 2013 to 2022, investment priorities in the renewable energy sector changed. Investments in solar and wind energy technologies increased significantly. In contrast, investments in other renewable technologies, such as hydropower (including pumped storage hydropower), biomass, biofuels, geothermal, and marine energy, decreased. Between 2017 and 2022, investments in these technologies fell by 45%, from USD 35 billion to USD 17 billion.

In 2023, the renewable energy sector saw a large increase in investments, especially in solar and wind technologies, totaling about USD 200 billion. This was a 75% increase compared to the previous year. These investments helped grow the GDP in key regions, including the United States, China, the European Union, and India, by between 1% and 4%.

Each year, the energy sector receives about USD 3 trillion in investments, with USD 1.9 trillion going toward clean energy technologies and infrastructure. To meet the goals of the Net Zero Emissions (NZE) Scenario by 2035, investments in clean energy must increase to USD 5.3 trillion per year.

Debates

Whether nuclear power is considered a type of renewable energy is a topic that people still discuss. Legal definitions of renewable energy usually do not include nuclear energy, except in the U.S. state of Utah. Definitions from dictionaries often leave out nuclear energy, except for the natural heat from nuclear decay inside Earth.

The most common fuel used in nuclear power plants, uranium-235, is called "non-renewable" by the U.S. Energy Information Administration. However, the organization does not mention recycled MOX fuel. The National Renewable Energy Laboratory does not include nuclear power in its basic definition of energy.

In 1987, the Brundtland Commission (WCED) said that reactors that create more nuclear fuel than they use (breeder reactors) and future fusion power should be grouped with renewable energy sources like solar and hydropower. Radioactive waste must also be managed and stored when using other renewable energy sources, such as geothermal energy.

The growing use of renewable energy affects how countries interact politically. Many oil-rich countries, such as Qatar, Russia, Saudi Arabia, and Norway, gain influence because of their oil. These countries may lose power during the shift to renewable energy, though Norway also produces and exports renewable energy. Fossil fuel resources and the systems used to extract them may become less valuable over time. Some countries that rely on oil income may sell their remaining fossil fuels quickly in the future.

At the same time, countries with lots of renewable energy resources and the minerals needed for renewable technology may gain influence. China is the main producer of technology for renewable energy, such as solar panels, wind turbines, and lithium-ion batteries. Countries with strong solar and wind resources could become major energy exporters. Some may produce and export green hydrogen, but electricity is expected to be the main energy source by 2050, making up almost half of total energy use. Countries with large, unused areas, like Australia, China, and many African and Middle Eastern nations, have the potential for large renewable energy projects. Producing renewable energy technology requires rare-earth elements, which need new supply chains.

Some African countries with weak governments that depend on oil income may face more political problems or unrest. Countries like Nigeria, Angola, Chad, Gabon, and Sudan, which have a history of military coups, are at risk of instability as oil income decreases.

A study found that switching from fossil fuels to renewable energy systems reduces risks from mining, trade, and political dependence because renewable energy systems do not need fuel. They only need materials and parts during construction.

In October 2021, European Commissioner for Climate Action Frans Timmermans said the best solution to the 2021 global energy crisis is to use less fossil fuel. He said critics of the European Green Deal were doing so for ideological or economic reasons. Some blamed the EU Emissions Trading System and the closure of nuclear plants for the energy crisis. European Commission President Ursula von der Leyen said Europe is too dependent on natural gas and needs to diversify suppliers and speed up the shift to clean energy.

Switching to renewable energy can improve a country's energy security and independence, reducing reliance on fossil fuel markets and political pressure from oil-producing countries. As the world becomes more electrified, renewable technologies will become important in many countries, especially developing ones, reducing the influence of oil-dependent nations.

The shift to renewable energy requires more mining for certain metals and minerals. This can harm the environment and cause conflicts. For example, lithium mining in the Salar de Atacama desert uses about 65% of the area’s water, forcing farmers and herders to leave their homes and causing environmental damage. In some African countries, the growth of renewable energy has led to mining booms, causing deforestation and threatening endangered species. Wind power needs large amounts of copper and zinc, as well as smaller amounts of neodymium. Solar power requires significant aluminum. Expanding electrical grids needs copper and aluminum. Batteries, which store renewable energy, use large amounts of copper, nickel, aluminum, and graphite. Demand for lithium is expected to grow 42 times by 2040. Demand for nickel, cobalt, and graphite is expected to increase by about 20–25 times. Each of these minerals is mainly mined in one country: copper in Chile, nickel in Indonesia, rare earths in China, cobalt in the Democratic Republic of the Congo, and lithium in Australia. China controls the processing of all these materials.

Recycling metals from old devices is important to create a circular economy and ensure renewable energy remains sustainable. By 2040, recycling copper, lithium, cobalt, and nickel from used batteries could reduce the need to mine these materials by about 10%.

Deep-sea mining is a controversial method of obtaining minerals like polymetallic nodules from the ocean floor. This could harm underwater life, but some argue that seabed ecosystems have less life than land mining areas, which are often in sensitive habitats like rainforests.

Rare-earth mining produces low-level radioactive waste because rare-earth elements often occur with radioactive materials like thorium, uranium, and radium.

Renewable energy installations, such as wind, solar, and hydropower plants, are growing and may threaten important conservation areas. These facilities are often built in places set aside for nature and other sensitive areas. They require much more land than fossil fuel plants, sometimes up to 10 times more land to produce the same amount of energy. Over 2,000 renewable energy projects are already built or under construction in areas important for wildlife, threatening plant and animal habitats. The researchers who studied this emphasized that their findings should not be seen as opposing renewable energy, which is vital for reducing carbon emissions. The key is to build renewable energy projects in places that do not harm biodiversity.

In 2020, scientists created a world map showing where renewable energy materials are found and how they overlap with areas important for biodiversity, untouched wilderness, and protected lands.

Society and culture

Solar power plants can sometimes take space that could be used for growing crops. On-shore wind farms are sometimes opposed because of concerns about how they look and the noise they make. People who oppose these projects are often called NIMBYs, which stands for "Not in My Back Yard." Some environmental groups worry that wind turbines can cause birds and bats to collide and die. Even though some people protest against new wind farms, studies in many areas show that most people support solar and wind energy.

One way to gain more support for wind farms is to have local communities own the wind energy projects. A 2011 UK government report said that projects are more likely to succeed when local people support them and have a say in the decisions. This includes giving communities both the chance to participate and a share in the benefits. In the 2000s and early 2010s, many renewable energy projects in Germany, Sweden, and Denmark were owned by local communities, often through cooperative groups. In recent years, more wind farms in Germany have been built by large companies, but community ownership is still common in Denmark.

History

Before coal was developed in the mid-1800s, most energy used was renewable. The earliest known use of renewable energy was burning traditional biomass, like plants and wood, to make fire. This practice began over a million years ago but became common much later, after hundreds of thousands of years. The second oldest use of renewable energy was using wind to move ships across water. This happened about 7,000 years ago, with ships in the Persian Gulf and on the Nile River. People have used heat from hot springs for bathing since the Paleolithic era and for heating spaces since ancient Roman times. During recorded history, the main sources of traditional renewable energy were human labor, animals, water power, windmills used for grinding grain, and firewood, which is a type of traditional biomass.

In 1885, Werner Siemens wrote about the discovery that sunlight can create electricity in solid materials. In 1905, Max Weber mentioned the future end of using fossil fuels in his book The Protestant Ethic and the Spirit of Capitalism. Solar energy use continued until World War I began. A 1911 article in Scientific American stated that solar power might be the only energy source left for humans once natural fuels ran out.

The idea of peak oil, which is when oil production reaches its highest point and then declines, was introduced in 1956. In the 1970s, environmentalists encouraged using renewable energy to replace oil once it ran out and to reduce reliance on oil. The first electricity-generating wind turbines were built during this time. Solar energy had been used for heating and cooling for a long time, but solar panels were too expensive to build large solar farms until 1980.

Government spending, rules, and policies helped the renewable energy industry survive the 2008 financial crisis and the Great Recession better than many other industries. In 2022, renewable energy provided 30% of the world’s electricity, compared to 21% in 1985.

Some of the most important historical uses of renewable energy (from ancient and traditional methods) include:

• Windmills in Europe and Asia, such as those in the Netherlands and Nashtifan, Iran. The oldest confirmed windmill designs date back to 700–900 CE in Iran.
• Water mills in Ancient China and Ancient Persia.
• Archimedes’ burning lens.
• Traditional cooling and ventilation systems that used windcatchers and solar chimneys.
• Buildings designed to use natural heat transfer and energy processes.
• Gravity-based fountains.
• Using animal-based biomass to make fuel bricks.
• Solar ovens and furnaces in Ancient China, India, Egypt, and Persia.
• Solar energy used for drying crops, shaping materials like pottery, and disinfecting items using sunlight.
• Long-distance water transport systems, like ancient qanat technology, used gravity to move water.
• Using sails on rivers, seas, and oceans to move goods and people.
• Using knowledge of water currents in rivers, seas, and oceans to move goods and people.
• Using renewable plants, such as desert shrubs and pruned branches, to create light and heat.
• Using renewable oils, like vegetable or animal-based oils, to create light and heat.
• Designing buildings to use natural sunlight during the day and moonlight at night for lighting, decoration, timekeeping, and other purposes.