Definition of Renewable Energy

The definition of renewable energy is any source of energy that is naturally replenishing and derived, directly or indirectly, from the environment.

Wind is a source of renewable energy.

To understand the definition of renewable energy and its benefits to the environment, you must also understand the dangers and limitation of using non-renewable energy sources for fuel and electricity.

Renewable energy sources, such as wind and solar power, are constantly replenished and infinite. No matter how much wind we harness to produce electricity, the planet’s supply of wind will not decrease or become threatened.

In contrast, non-renewable energy sources, such as coal and oil, will eventually dwindle and become too damaging or expensive to collect and use for energy production.

Approximately seven percent of energy usage in the United States comes from renewable sources, with most of that going toward electricity production. Most renewable energy comes from six main sources: wind, hydrogen, organic matter, water, geothermal heat, and the sun.

The sun is the most abundant source of renewable energy. Solar energy is used for electricity generation, heating and lighting buildings, hot water heating, and numerous industrial and commercial uses. Solar panels capture the sun's energy for conversion into usable energy.

Wind turbines harness wind energy for use in farming and electricity generation. Smaller wind machines can supply energy to commercial and residential buildings. Wind energy is infinite, pollution-free, and does not produce radioactive or toxic waste.

Hydrogen occurs naturally in many organic compounds and in water. While it does not occur in gas form, separating hydrogen from other elements, such as oxygen, makes it useful as a renewable energy source. Scientists can convert hydrogen into electricity or burn it as a fuel.

Plants absorb sunlight during photosynthesis. Some of this sunlight remains inside the plant material, or biomass, in the form of energy. Biomass releases stored energy in four ways: burning, fermentation, bacterial decay, and conversion to gas. This organic plant matter, or biomass, is a source of energy for electricity production and transportation fuel.

Geothermal heat comes from deep within the planet's core, where decaying radioactive materials produce energy. Geothermal heat is useful for producing electricity and heating and cooling homes and other buildings.

Water energy, or hydropower, comes from the mechanical energy of the tides and waves. As water flows, it naturally produces energy that is convertible to electricity.

The use of non-renewable energy sources, such as fossil fuels, releases pollutants into the air. Burning fossil fuels increases greenhouse gas emissions and contributes to global warming. Non-renewable energy sources also use and pollute water supplies, harm plant and animal life, and increase toxic waste production.

By reducing our reliance on fossil fuels and increasing use of renewable energy, we reduce air and water pollution, conserve water and other natural resources, preserve the food chain and prevent destruction of ecosystems, and help slow global warming.

Renewable energy is more expensive to produce and more difficult to collect than fossil fuels. Moreover, renewable energy sources are not reliable, with many dependent on weather conditions or other factors outside human control. Even so, use of renewable energy sources is on the rise.

Due to increased concerns about global warming, rising gas and oil prices, and government incentives, more and more people are looking into ways to reduce their dependence on fossil fuels. As more consumers turn to renewable energy to power their cars and homes, the demand for fossil fuels declines. The Energy Information Administration expects the use of renewable energy to increase over the next several decades.

For more information on the definition of renewable energy, visit the National Renewable Energy Laboratory website.

• Ways to Prevent Global Warming
• 50 Specific Actions of Green Living
• Examples of Sustainable Development

• United States Recycling Statistics
• Types of Pollution
• Air Pollution Statistics
• Effects of Water Pollution
• Advantages and Disadvantages of Biofuels