Renewable energy facts for kids
Renewable energy is power that comes from natural sources that can refill themselves. Think of it like a never-ending supply! These sources include sunlight, wind, the movement of water, and heat from inside the Earth.
Most renewable energy sources are good for the long term, meaning they won't run out. Renewable energy is often used to make electricity, and for heating and cooling our homes and buildings.
Renewable energy is becoming more and more popular. From 2011 to 2021, the amount of global electricity made from renewable sources grew from 20% to 28%. This means we are using less fossil fuels (like coal and oil) and more clean energy. Power from the sun and wind has grown a lot, now making up 10% of global electricity.
Around the world, over 10 million jobs are linked to renewable energy. Making solar panels, for example, is a huge job creator. Renewable energy systems are getting better and cheaper very quickly. In many places, solar and wind power are now the cheapest ways to build new electricity plants.
Many countries already get more than 20% of their energy from renewable sources. Some even get over half their electricity this way! A few countries even get all their electricity from renewables. Experts believe that by 2050, 90% of global electricity will need to come from renewable sources to help stop climate change.
Renewable energy sources are found all over the world, unlike fossil fuels which are only in certain places. Using renewable energy helps keep our energy supply safe, fights climate change, and boosts the economy. People around the world strongly support solar and wind power.
Why Renewable Energy Matters for Our Planet
To fight climate change, most countries are working to greatly reduce greenhouse gases. This means we need to stop using fossil fuels and switch to energy sources that produce less pollution. At a big meeting in 2023, about three-quarters of the world's countries agreed to triple their renewable energy use by 2030. The European Union wants 40% of its electricity to come from renewables by then.
Renewable energy is also spread out more evenly around the world than fossil fuels. It also makes us healthier by cutting down on air pollution from burning fossil fuels. This could save trillions of dollars in healthcare costs every year!
A Look Back at Renewable Energy
New government spending and rules helped the renewable energy industry grow, even during tough economic times. In 2022, renewable sources made 30% of the world's electricity. This is a big jump from 21% in 1985.
Main Types of Renewable Energy
Solar Energy
Solar power uses energy from the sun. In 2022, solar power made about 4.6% of the world's electricity. Most of this growth has happened since 2010. You can use solar energy anywhere the sun shines! However, how much electricity you can make depends on the weather, where you are, and the time of day.
There are two main ways to use solar energy:
- Solar thermal: This turns sunlight into heat.
- Photovoltaics (PV): This turns sunlight directly into electricity. PV is much more common and is growing faster.
Some buildings are designed to use passive solar energy. This means they are built to naturally collect and store heat from the sun, like using special windows or materials that hold heat.
How Solar Panels Work
A photovoltaic system uses solar cells (often grouped into panels) to change light into electricity. This happens through something called the photoelectric effect. Most solar cells today are made from crystalline silicon.
PV has many benefits:
- It's cheap.
- It doesn't need much maintenance.
- You can easily add more panels if you need more power.
The main downside is that it doesn't work as well on cloudy days.
Solar systems can be small, like panels on a house roof, or very large, like huge solar farms. Rooftop panels use existing space to make power right where it's needed. About 25 million homes worldwide use rooftop solar power. Australia has the most rooftop solar per person.
The first big solar power plant was built in California in 1982. At first, it wasn't very profitable. But over the years, solar technology got much better. Solar panels became more efficient at making electricity and cheaper to install. Now, solar power is often as cheap as traditional electricity. Because of this, solar power has grown incredibly fast since 2010.
China has added a huge amount of solar power, more than all advanced countries combined. Four of the ten biggest solar power stations are in China. Some large solar farms use tracking systems that follow the sun across the sky to make even more electricity.
Solar Thermal Energy
Solar thermal energy (STE) is a form of energy and a technology for harnessing solar energy to generate thermal energy for use in industry, and in the residential and commercial sectors.
Solar thermal collectors are classified by the United States Energy Information Administration as low-, medium-, or high-temperature collectors. Low-temperature collectors are generally unglazed and used to heat swimming pools or to heat ventilation air. Medium-temperature collectors are also usually flat plates but are used for heating water or air for residential and commercial use.
High-temperature collectors concentrate sunlight using mirrors or lenses and are generally used for fulfilling heat requirements up to 300 deg C / 20 bar pressure in industries, and for electric power production. Two categories include Concentrated Solar Thermal (CST) for fulfilling heat requirements in industries, and Concentrated Solar Power (CSP) when the heat collected is used for electric power generation. CST and CSP are not replaceable in terms of application.
The largest facilities are located in the American Mojave Desert of California and Nevada. These plants employ a variety of different technologies. The largest examples include, Ivanpah Solar Power Facility (377 MW), Solar Energy Generating Systems installation (354 MW), and Crescent Dunes (110 MW). Spain is the other major developer of solar thermal power plant. The largest examples include, Solnova Solar Power Station (150 MW), the Andasol solar power station (150 MW), and Extresol Solar Power Station (100 MW).Solar thermal energy uses the sun's heat for things like warming water or heating buildings. It can also be used in large power plants to create steam that drives turbines to make electricity.
Wind Power
People have used wind energy for thousands of years, mainly to power ships, windmills, and water pumps. Today, most wind power is used to make electricity with wind turbines.
Modern wind turbines are very large, some producing enough power for thousands of homes. The stronger the wind, the more electricity a turbine can make. Places with strong, steady winds, like offshore (in the ocean) or on high hills, are best for wind farms.
In 2015, wind power made almost 4% of the world's electricity. It was the top new energy source in Europe, the US, and Canada. In Denmark, wind energy met over 40% of its electricity needs!
Experts believe that wind energy could provide much more power than we currently use globally. This would mean putting turbines in many areas, especially offshore where winds are stronger.
Hydropower
Water is much heavier than air, so even a slow stream or ocean wave can create a lot of energy. Water can turn into electricity with about 90% efficiency, which is very high for renewable energy.
Here are different ways we use water for energy:
- Large Dams: Historically, hydropower came from building huge dams and reservoirs. The biggest are the Three Gorges Dam in China and the Itaipu Dam between Brazil and Paraguay.
- Small Hydro: These are smaller power plants, often on smaller rivers. China has many thousands of these.
- Run-of-the-river: These plants use the natural flow of a river without needing a large dam. Water is directed through pipes to spin turbines.
Hydropower is used in 150 countries. Many countries that get most of their electricity from renewables use hydropower. The world has only developed about a third of its possible hydropower.
New hydropower projects can face challenges because they can affect local communities and wildlife. However, updating old dams to make them more efficient is a popular way to increase hydropower. Some dams can even be updated with "pump-back" systems to store energy, which is helpful when wind and solar power aren't producing as much.
Bioenergy
Biomass is material that comes from living or recently living things, usually plants. We can use biomass directly by burning it for heat, or by turning it into different types of biofuel (solid, liquid, or gas).
Wood was the biggest source of biomass energy in 2012. This includes things like dead trees, branches, and even garbage. Special crops like miscanthus or sugarcane can also be grown just for energy.
Biomass can be turned into other useful forms of energy:
- Methane gas: This gas, also called landfill gas or biogas, comes from rotting garbage and animal waste.
- Ethanol: Crops like corn and sugarcane can be fermented to make ethanol, which is used as a fuel for vehicles.
- Biodiesel: This fuel can be made from leftover cooking oils and animal fats.
There's also a lot of research into algae fuel. Algae grows very fast, doesn't need farmland, and can be turned into many different biofuels.
Burning biomass, biogas, and biofuels can release pollutants into the air. For example, burning wood for cooking indoors can cause serious health problems for billions of people worldwide.
In 2021, bioenergy provided 158 GW of power globally. Biofuels also helped reduce the need for traditional transport fuels by 4.4%.
Biofuel
Biofuels are fuels made from biomass. They can be solid, liquid, or gas.
- Liquid biofuels: These include bioethanol and biodiesel.
* Bioethanol is an alcohol made by fermenting sugars from plants like corn or sugarcane. It's often mixed with gasoline for cars. Brazil is a big producer of bioethanol from sugarcane. * Biodiesel is made from vegetable oils or animal fats. It can be used in diesel engines, often mixed with regular diesel to reduce pollution.
- Gaseous biofuels: These include biogas and landfill gas.
Policies in over 80 countries support the use of biofuels.
Geothermal Energy
High-temperature geothermal energy comes from the heat deep inside the Earth. This heat is created by the planet's formation and from radioactive decay of minerals. The deeper you go into the Earth, the hotter it gets! This heat moves from the Earth's core to the surface. Sometimes, the heat is so intense it melts rock, creating magma. This magma then heats up rocks and water closer to the surface.
Low-temperature geothermal energy uses the Earth's outer crust like a giant battery to help heat and cool buildings. A geothermal heat pump moves heat into the Earth for cooling in summer and pulls heat out of the Earth for heating in winter. This type of geothermal energy is becoming very important because it saves energy and helps balance electricity use.
Geothermal power is reliable and good for the environment. It used to be limited to areas near tectonic plate boundaries (where Earth's plates meet), but new technology is changing that. Geothermal wells can release some greenhouse gases, but usually much less than fossil fuels.
In 2017, the United States was the top producer of geothermal electricity. The largest group of geothermal power plants is at The Geysers in California. The Philippines is the second-highest producer.
In 2021, global geothermal power capacity was 15 GW.
New and Developing Technologies
There are other renewable energy technologies that are still being developed. These include concentrated solar power, advanced geothermal systems, and marine energy (from the ocean). These technologies are not yet widely used, but they have great potential.
Many scientists and researchers are working to improve renewable energy. Their main goals are to make these technologies more efficient and produce even more energy.
Enhanced Geothermal Systems
Enhanced geothermal systems (EGS) are a new way to get geothermal power. They don't need natural hot water sources. Most of the Earth's heat within drilling reach is in dry, non-porous rock. EGS technology "enhances" these areas by using hydraulic fracturing to create pathways for water to flow and get heated.
EGS systems could provide power 24 hours a day, just like fossil fuel plants. They could also be built almost anywhere in the world, depending on how deep we can drill. There are EGS projects being tested in many countries, including France, Australia, and the U.S. The largest EGS project is in Australia.
Marine Energy
Marine energy (or ocean energy) comes from the power of ocean waves, tides, and ocean temperature differences. The movement of water in the oceans holds a huge amount of energy. This energy can be used to make electricity for homes, transportation, and industries.
Marine energy includes:
- Wave power: Energy from surface waves.
- Marine current power: Energy from ocean currents.
- Tidal power: Energy from the rise and fall of tides.
Offshore wind power is different; it uses wind, even if the turbines are in the water. The oceans have a massive amount of energy and are close to many large populations, so ocean energy could provide a lot of new renewable energy worldwide.
Passive Daytime Radiative Cooling
Passive daytime radiative cooling (PDRC) uses the coldness of outer space to cool things during the day. It's a renewable energy source for cooling! PDRC surfaces are designed to reflect a lot of sunlight and also release heat into space. This can be used for cooling buildings, reducing heat in cities, and even making solar panels work better.
This technology became possible in 2014 with new materials. PDRC applications are growing, with a market expected to be worth about $27 billion by 2025.
Other Developing Technologies
Algae Fuels
Scientists are researching how to make liquid fuels from certain types of algae that are rich in oil. Algae can be grown in different systems, even in deserts.
Water Vapor
Collecting static electricity from water droplets on metal surfaces is an experimental technology. It could be very useful in countries with high air humidity.
Artificial Photosynthesis
Artificial photosynthesis tries to copy how plants use sunlight to make energy. Researchers are trying to find ways to store solar energy in chemical bonds, like splitting water to make hydrogen or using carbon dioxide to make methanol. This field uses nanotechnology to create tiny systems that can capture sunlight more efficiently.
How Much Does Renewable Energy Cost?
The International Renewable Energy Agency (IRENA) reported that in 2022, about 86% of new renewable energy projects cost less than electricity made from fossil fuels. IRENA also said that renewable energy added since 2000 has saved billions of dollars on electricity bills.
| Installed TWp |
Growth TW/yr |
Production per installed capacity* |
Energy TWh/yr* |
Growth TWh/yr* |
Levelized cost US¢/kWh |
Av. auction prices US¢/kWh |
Cost development 2010–2019 |
|
|---|---|---|---|---|---|---|---|---|
| Solar PV | 0.580 | 0.098 | 13% | 549 | 123 | 6.8 | 3.9 | −82% |
| Solar CSP | 0.006 | 0.0006 | 13% | 6.3 | 0.5 | 18.2 | 7.5 | −47% |
| Wind Offshore | 0.028 | 0.0045 | 33% | 68 | 11.5 | 11.5 | 8.2 | −30% |
| Wind Onshore | 0.594 | 0.05 | 25% | 1194 | 118 | 5.3 | 4.3 | −38% |
| Hydro | 1.310 | 0.013 | 38% | 4267 | 90 | 4.7 | +27% | |
| Bioenergy | 0.12 | 0.006 | 51% | 522 | 27 | 6.6 | −13% | |
| Geothermal | 0.014 | 0.00007 | 74% | 13.9 | 0.7 | 7.3 | +49% |
* = 2018. All other values for 2019.
The Growth of Renewables
As countries become responsible for the damage caused by greenhouse gas emissions, there's a strong push to use more renewable energy.
From 2010 to 2019, countries around the world invested about $2.7 trillion in renewable energy. China invested the most, followed by the United States, Japan, Germany, and the United Kingdom. This was a huge increase compared to the previous decade.
As of 2022, about 28% of the world's electricity came from renewable sources, up from 19% in 1990.
Discussions About Renewable Energy
Electricity from wind and solar can change depending on the weather. This means we sometimes need other power sources, like gas plants, ready to go. We also need better ways to store energy, manage demand, and improve the power grid.
The market for renewable energy is still growing. Concerns about climate change, more green jobs, and government support are all helping to push for more renewable energy laws and projects.
The International Energy Agency says that using renewable energy helps us have many different ways to get electricity. It also makes our power system more flexible and stronger against big problems.
Public Opinion
Sometimes, solar farms might take up land that could be used for farming. On-shore wind farms can also face opposition because of how they look or the noise they make. For example, a wind project in Massachusetts was delayed for years partly due to concerns about its appearance. However, people in other areas have been very positive.
A UK government document from 2011 said that energy projects are more likely to succeed if local communities support them and feel like they are part of the project. In countries like Germany and Denmark, many renewable energy projects are owned by communities, which helps them grow a lot.
Health and Environmental Benefits
Switching to modern renewable energy has huge health benefits because it reduces air pollution from fossil fuels.
Renewable sources like wind power, photovoltaics, and hydroelectricity also help save water, lower pollution, and reduce carbon dioxide emissions.
Solar panels can change how much sunlight the Earth's surface reflects. If used on a very large scale, like covering a big part of the Sahara Desert, they could even change global weather patterns.
See also
In Spanish: Energía renovable para niños
- Distributed generation
- Efficient energy use
- Energy harvesting
- Energy security
- Energy storage
- Energy poverty
- Fuel efficiency
- Fossil fuel phase-out
- Mass production in renewable energy sector
- Energy transition
- Thermal energy storage
- List of countries by renewable electricity production
- List of renewable energy topics by country and territory
- Renewable heat
