Renewable Energy - the future of energy
Renewable energy refers to energy generated from natural sources, like the sun and wind, that are in constant supply. Renewable energy resources are carbon neutral and represent the evolution of the world's energy supply away from fossil fuels. The main renewable energy sources are:
- Hydroelectric Power - power derived from falling water on dams or rivers
- Solar Energy - energy from the sun's daily renewable energy supply
- Wind Power - weather makes the wind blow - renewable energy is a breeze
- Biomass Energy - as long as plants grow, they will provide a renewable resource
- Geothermal Energy - vast, constant and renewable energy source from the earth's core
- Tidal Energy - renewable energy source from the predictable change of the tides
Renewable Energy is the future of energy
Renewable energy got a big boost when gasoline prices hit $5 a gallon in 2008. As prices rose and politicians bellowed, the American public became painfully aware of it's over-dependence on foreign sources of oil. With prices at the $4 per gallon level, the economics of renewable energy are quite favorable.
Renewable Energy Basics
The United States currently relies heavily on coal, oil, and natural gas for its energy. Fossil fuels are nonrenewable, that is, they draw on finite resources that will eventually dwindle, becoming too expensive or too environmentally damaging to retrieve. In contrast, renewable energy resources—such as wind and solar energy—are constantly replenished and will never run out.
Renewable energy plays an important role in the supply of energy. When renewable energy sources are used, the demand for fossil fuels is reduced. Unlike fossil fuels, non-biomass renewable sources of energy (hydroelectric power, geothermal, wind, tidal, and solar) do not directly emit greenhouse gases.
The use of renewable energy is not new. More than 150 years ago, wood, which is one form of biomass, supplied up to 90 percent of our energy needs. As the use of coal, petroleum, and natural gas expanded, the United States became less reliant on wood as an energy source. Today, we are looking again at renewable resources to find new ways to use them to help meet our energy needs.
Most renewable energy goes to the production of electricity. The creation of heat and steam for industrial purposes is the next largest use of renewable energy. Renewable fuels, such as ethanol or other biofuels
, are also used for transportation and to provide home and business heating.
Renewable Energy - solar
Most renewable energy comes either directly or indirectly from the sun. Sunlight, or, solar energy, can be used directly for heating and lighting homes and other buildings, for generating electricity, and for hot water heating, solar cooling, and a variety of commercial and industrial uses. Step outside on a hot, sunny day, and you'll experience the power of the sun's heat and the light. That's solar energy.
Renewable Energy - Wind
The sun's heat also drives the winds, whose energy is captured with wind turbines. We have harnessed the wind's energy for hundreds of years—from windmills that pump water or grind grain to today's wind turbines that generate electricity.
If you live on at least one acre of land with an ample wind resource, you can generate your own electricity using residential wind power. You can also use a small wind turbine for pumping water.
You may have the opportunity now or in the future to buy clean electricity from a wind farm.
Renewable Energy - Biomass
Along with the rain and snow, sunlight causes plants to grow. The organic matter that makes up those plants is known as biomass. Biomass can be used to produce electricity, transportation fuels, or chemicals. The use of biomass for any of these purposes is biomass energy.
Ever since humans started burning wood or other organic matter to keep warm and to cook food, we've been using biomass energy, or bioenergy. Today we can also use biomass to fuel vehicles, generate electricity, and develop biobased products.
Renewable Energy - Geothermal
Not all renewable energy resources come from the sun. The Earth's heat, which constantly flows outward from its core, provides an enormous source of energy called geothermal energy. Geothermal energy taps the Earth's internal heat for a variety of uses, including electric power production, and the heating and cooling of buildings. And the energy of the ocean's tides comes from the gravitational pull of the moon and the sun upon the Earth.
Renewable Energy - Tidal
The ocean can produce thermal energy from the sun's heat and mechanical energy from the tides and waves. Oceans cover more than 70% of the Earth's surface. As the world's largest solar collectors, oceans generate thermal energy from the sun. They also produce mechanical energy from the tides and waves. Even though the sun affects all ocean activity, the gravitational pull of the moon primarily drives the tides, and the wind powers the ocean waves.
Renewable Energy - Hydroelectric
Flowing water creates energy that can be captured and turned into electricity. This is called hydroelectric power or hydropower. If you have access to flowing water on your property, you can use a microhydropower system to generate your own electricity.
Why Don’t We Use More Renewable Energy?
In the past, renewable energy has generally been more expensive to use than fossil fuels. Plus, renewable resources are often located remote areas and it is expensive to build power lines to the cities where they are needed. The use of renewable sources is also limited by the fact that they are not always available (for example, cloudy days reduce solar energy, calm days mean no wind blows to drive wind turbines, droughts reduce water availability to produce hydroelectricity).
The production and use of renewable fuels has grown more quickly in recent years due to higher prices for oil and natural gas, and a number of State and Federal Government incentives. The use of renewable fuels is expected to continue to grow over the next 30 years, although we will still rely on non-renewable fuels to meet most of our energy needs.
Source: Department of Energy