Renewable Energy

Renewable energy is energy that comes from sources that nature replaces quickly. The wind keeps blowing. The sun keeps shining. Rivers keep flowing. These sources do not run out the way coal, oil, and natural gas do. Fossil fuels took hundreds of millions of years to form underground. Once we burn them, they are gone for a very long time.

There are several main types of renewable energy. Each one turns something in nature into electricity or heat.

Solar energy comes from the sun. Solar panels are made of special materials that turn sunlight directly into electricity. You can see them on rooftops, on calculators, and in huge fields called solar farms. Sunlight can also heat water for homes.

Wind energy uses moving air. Tall wind turbines have giant blades that spin when the wind blows. The spinning turns a machine called a generator, which makes electricity. Some wind turbines are taller than a 50-story building. The longest blades are almost as long as a football field.

Hydropower uses moving water, usually from a river held back by a dam. When water flows through the dam, it spins turbines and makes electricity. Hydropower is the oldest kind of renewable energy. People used flowing water to turn mill wheels thousands of years ago.

Geothermal energy uses heat from inside the Earth. In some places, hot water and steam rise close to the surface. Power plants use the steam to spin turbines. Iceland gets most of its heat and much of its electricity this way.

Biomass energy comes from plants and plant waste. Burning wood is the oldest example. Today, some power plants burn leftover cornstalks or wood chips. Other plants can be turned into a fuel called biodiesel.

Renewable energy has grown very fast. In 2000, it made only a small slice of the world's electricity. By 2024, renewable sources made about 30 percent of it. One big reason people want more renewable energy is climate change. Burning fossil fuels releases carbon dioxide, a gas that warms the planet. Wind, sun, and water do not release this gas.

Renewable energy has real challenges too. The sun does not shine at night. The wind does not always blow. Dams can hurt fish and flood land where people lived. Scientists and engineers are working on better batteries to store clean energy for later. The question of how fast the world should switch away from fossil fuels is one of the biggest debates of our time.