Renewable energy

Nature gives us many ways to make power.

We can use the sun and the wind. We can also use water from big dams.

Some power comes from the sun. This only works during the day. Wind power can change too. It might be windy or calm.

We can save this power in big batteries. This helps us when the sun goes down. Using these tools keeps our air clean. It also helps keep our world healthy.

Renewable energy comes from natural sources. These sources fill up quickly. We call this green energy.

Solar power uses sunlight. It can be captured in two ways. One way is solar thermal. This turns light into heat. The other way is photovoltaics. These are parts that turn light into electricity.

Wind power uses the moving air. Hydropower uses moving water. Some power comes from deep in the Earth. This is called geothermal power.

Some energy sources are variable. This means they change. The sun does not shine at night. The wind does not always blow. These sources are called intermittent.

We can use batteries to store power. This helps us when the sun goes down. This keeps our air clean. It also helps our health. Using these tools can reduce pollution. Most countries want to use more renewables. They want to reach net zero by 2050. This means they want to stop adding bad gases to the air.

Renewable energy is energy made from natural sources. These sources are replenished on a human timescale. This means they fill up as fast as we use them. People often call this green energy.

It is very important for our planet. Using these sources helps reduce greenhouse gas emissions. These emissions are what cause climate change. Most renewable energy pollutes much less than fossil fuels. It also makes our air cleaner. This can help improve public health for everyone.

There are many ways to make this energy. Solar power uses sunlight to create power. It works through solar thermal or photovoltaics. Photovoltaics, or PV, turn light directly into electricity.

Wind power uses the moving air. Hydropower uses the movement of water, like in a dam.

Geothermal power comes from heat deep inside the Earth.

Bioenergy uses biological materials to make power. Each of these methods works in different ways.

Scientists and leaders have tracked these changes for a long time. For many years, people mostly used fossil fuels. However, things have changed quickly in the last 30 years. Renewable systems have become much more efficient. They have also become much cheaper to build. From 2011 to 2021, renewables grew significantly. They went from 20% to 28% of the global electricity supply.

In 2024, renewables made up over 30% of global electricity. This shows how fast the world is shifting.

Some renewable sources are called intermittent. This means they are not always available. Solar energy needs the sun to shine during the day. Wind power changes based on how much the air moves.

Other sources, like hydropower or geothermal, are controllable. They can provide steady power when we need it. To help with the changing wind and sun, we use storage. Batteries can hold electricity for later use. Pumped-storage hydroelectricity is a huge part of this. It makes up over 85% of all grid power storage.

Renewable energy connects to many parts of our lives. It can power our homes and our cars. Using electricity for vehicles is a very clean way to travel. Many countries have big goals for the future. At a 2023 United Nations conference, many nations made a plan. They want to triple renewable energy capacity by 2030. The European Union wants 40% of its electricity to be renewable by then.

This helps us move toward a goal called net zero by 2050.

Renewable energy, often called green energy, comes from natural resources that replenish themselves on a human timescale. The International Energy Agency defines these as energy sources derived from natural processes that replenish faster than they are consumed. This distinguishes them from fossil fuels, which take millions of years to form. These resources are essential for modern life because they can provide electricity, heat water, and power transportation. Today, renewable energy is being used to replace conventional fuels in many different sectors.

There are several main ways we harness these natural forces. Solar power captures energy from the sun through two primary methods. Solar thermal converts sunlight into heat, while photovoltaics, or PV, convert light directly into electricity. PV is currently more widespread and is growing much faster than solar thermal.

Wind power uses the movement of air to generate electricity. Hydropower uses the movement of water, often through large structures like dams.

Geothermal energy taps into the heat from deep inside the Earth. Finally, bioenergy uses biological materials to create power.

Scientists categorize these energy sources based on how they behave. Some are considered variable or intermittent energy sources. Solar and wind are the most common examples because they fluctuate. Solar energy requires daylight and clear skies to work most effectively. Wind power can change significantly from day to day or even month to month.

In contrast, other sources are considered controllable. Dammed hydroelectricity, bioenergy, and geothermal power can provide a steady supply of energy. This allows grid operators to produce the specific amount of electricity required at any given time.

To manage the variability of wind and solar, we use electrical energy storage. This involves collecting energy when production exceeds consumption and returning it to the grid when production falls. Pumped-storage hydroelectricity is currently the most common method, accounting for more than 85% of all grid power storage. Batteries are also being used more often for domestic storage and grid services. Another method involves green hydrogen, which can serve as a more economical way to store energy over the long term. These technologies help ensure that electricity is available even when the sun is not shining or the wind is not blowing.

Renewable energy has seen massive growth and cost reductions over the last 30 years. Between 2011 and 2021, the share of global electricity from renewables grew from 20% to 28%. During this time, solar and wind power were the main drivers, growing from a combined 2% to 10% of the supply. By 2024, renewables accounted for over 30% of global electricity generation. Experts project that this figure will reach over 45% by 2030.

In some locations, installing solar or wind is now the cheapest way to build new electricity capacity.

Transitioning to these sources is a major part of the global effort to address climate change. Most countries have committed to reaching net zero greenhouse gas emissions. This involves replacing fossil fuels with low-emissions energy sources to reduce the greenhouse gases that cause climate change. 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 has also set a goal to generate 40% of its electricity from renewables by 2030.

While the benefits are many, there are still significant challenges to overcome. The deployment of renewables faces obstacles like fossil fuel subsidies and local opposition to land use. There are also risks regarding energy security and infrastructure. For example, 90% of the supply chain for photovoltaic solar is centralized in China. This creates risks for the global supply. Additionally, renewable infrastructure can be vulnerable to extreme weather events like heat waves or storms.

Despite these hurdles, the shift toward a cleaner, more distributed energy system continues to accelerate.