Renewable energy sources are, by definition, constantly replenished. Fossil fuels like coal or gasoline burn up and are gone, but the sun keeps shining and the wind keeps blowing, no matter how many homes use them to make electricity.

The main types of renewable energy sources include solar, wind, geothermal, bioenergy, hydropower, and hydrogen. These types of energy are also called clean energy.

Below, we take a closer look at six of the most common alternative energy types, along with their benefits:

Solar Power

Solar power is a type of renewable energy that captures the sun’s energy. There are several types of solar power, but the best known is photovoltaic (PV) solar, which uses solar cell technology to convert sunlight.

SunPower® solar panels feature Maxeon® solar cells that contain a unique, light-trapping surface to harvest power from visible light as well as infrared and ultraviolet light waves. It’s this technology that not only makes SunPower solar panels the most efficient in the market1 but also helps solar system owners generate enough power to save money over time. And with the most comprehensive 25-year warranty in the industry, a SunPower solar system can go on to produce clean energy for decades.

Wind

Wind and solar are the two fastest-growing types of utility-scale electrical generation in the United States, according to the U.S. Department of Energy. Giant turbines capture wind flow and turn it into electricity. In fact, wind turbines can convert almost half of the wind that hits them into electrical power.

Geothermal

Geothermal power plants harness heat generated from the earth, usually in areas near volcanoes or tectonic activity, though geothermal power can be found in other places as well. A geothermal plant can be put on a small plot of land as long as there’s plenty of heat coming up from the earth.

Bioenergy

People have been using biological matter to create energy for centuries. This can include a simple campfire or turning biological matter into fuel (like using corn to make ethanol for cars). Bioenergy can also involve using bacteria to release gas that can generate power. Materials for bioenergy can be found everywhere, and using them for this purpose often gets rid of waste in a constructive way.

Hydropower

This type of energy is created by moving water. Damming a river forms a reservoir, and the water from the reservoir spins a turbine that produces electricity.

Hydrokinetics uses the energy that moving water generates, just like hydropower. However, hydrokinetic power uses the motion of ocean waves and free-flowing water in rivers.

The vast oceans that cover more than 70% of the planet can generate energy that spinning turbines can use. More than half of Americans live near coastlines, so that the power would be near large population centers. However, hydrokinetic energy is still largely experimental, and the environmental impacts on marine life remain unclear.

Hydrogen

Hydrogen is the most common element in the universe, and it can generate a lot of energy while producing little or no pollution. Liquid hydrogen has been used since the 1950s to launch rockets into orbit. Hydrogen fuel cells in cars and other vehicles convert the potential chemical energy of hydrogen into electricity, with water and heat as the only byproducts.

All of the sources mentioned above have been developed to create a more environmentally friendly approach toward powering our world. Unlike fossil fuels, which have a limited lifespan, these six types of alternative energy provide innovative solutions to utilize resources that are readily available. Some, like bioenergy, are even taking on two environmental challenges by eliminating both greenhouse gasses and waste. These efforts, paired with their increasing affordability, provide more accessibility to cleaner power options, making them more commonplace.

While many of the forms mentioned above are still being perfected, solar technology remains one of the least polluting forms of renewable energy, as well as one of the most affordable. With multiple solar solutions that are readily available for home and business installation, SunPower provides an easy and reliable way to start enjoying the benefits of renewable energy right away. To find out more about how to go solar, sign up for an online consultation with one of our knowledgeable solar consultants.

This post originally appeared on the SunPower Resource Blog.