Renewable and Green Energy

Renewable energy is energy drawn from natural sources that are replenished faster than they are consumed, in contrast to fossil fuels, which exist in finite quantities and take geological ages to form. Because renewable sources are continually renewed by natural processes and generally produce little or no pollution during use, they are central to efforts to reduce contamination of the air and water and to limit the emissions linked to climate change.

Solar energy is among the most widely used renewable resources. Photovoltaic solar cells convert sunlight directly into electricity, while solar thermal systems capture the sun's heat to warm water or to generate electricity by driving turbines. Wind energy converts the motion of air into electrical power through turbines. Both depend on natural flows that are constantly renewed, though their output varies with weather and time of day, which makes energy storage and a mix of sources important for a reliable supply.

Biomass is another renewable source, using organic material such as plant matter and agricultural by-products as fuel. Biomass can be burned directly or processed into liquid fuels; biodiesel, for example, is made from vegetable oils or animal fats and produces glycerol as a by-product. Other renewable sources include flowing water and the heat of the Earth. Together these alternatives to fossil fuels aim to provide energy while reducing pollution and the greenhouse gas emissions that contribute to global warming, supporting a more sustainable energy supply.

Frequently asked questions

What makes energy renewable?

Renewable energy comes from sources replenished by natural processes faster than they are used, such as sunlight, wind, and growing plant matter, unlike finite fossil fuels.

What is biodiesel?

Biodiesel is a fuel made from vegetable oils or animal fats. It is a form of biomass energy, and its production yields glycerol as a by-product.

Why is renewable energy linked to the environment?

Renewable sources generally produce little pollution and few greenhouse gas emissions during use, so replacing fossil fuels with them helps reduce contamination and global warming.