Home
Who We Are
Medford's Efforts
What You Can Do
News & Events
Fact Sheets
Resources & Links
Contact Us

Fact Sheets

Renewable Energy Sheet;
The following information has been gathered from:
The U.S. Dept. of Energy Efficiency and Renewable Energy AND
The National Renewable Energy Laboratory

 

Wind Energy:

We have been harnessing the wind's energy for hundreds of years. From old Holland to farms in the United States, windmills have been used for pumping water or grinding grain. The windmill's modern equivalent -a wind turbine- can use the wind's energy to generate electricity.

Wind turbines, like windmills, are mounted on a tower to capture the most energy. Turbines catch the wind's energy with their propeller-like blades. Usually, two or three blades are mounted on a shaft to form a rotor. Wind, for the most part, is a reliable source of renewable energy that produces zero emissions thereby increasing our local air quality.

Solar:

Solar energy works anytime that the sun is shining, but more electricity is produced the stronger the sun shines.

There are a variety of technologies that have been developed to take advantage of solar energy (energy produced by the sun). These include:

  • Photovoltaic (solar cell) systems: Producing electricity directly from sunlight.
  • Concentrating solar systems: Using the sun's heat to produce electricity.
  • Passive solar heating and daylighting: Using solar energy to heat and light buildings.
  • Solar hot water: Heating water with solar energy.
  • Solar process heat and space heating and cooling: Industrial and commercial uses of the sun's heat.

Ocean Energy:

Oceans cover more than 70% of Earth's surface, making them the world's largest solar collectors. The sun's heat warms the surface water a lot more than the deep ocean water, and this temperature difference creates thermal energy. Just a small portion of the heat trapped in the ocean could power the world.

The ocean can produce two types of energy: thermal energy from the sun's heat, and 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. Because ocean energy is abundant and non-polluting, today's researchers are exploring ways to make ocean energy economically competitive with fossil fuels and nuclear energy.

Geothermal Energy:

The word "geothermal" literally means "Earth" plus "heat." The geothermal resource is the world's largest energy resource and has been used by people for centuries. In addition, it is environmentally friendly. It is a renewable resource and can be used in ways that respect rather than upset our planet's delicate environmental balance.

The Earth's crust is a bountiful source of energyčand fossil fuels are only part of the story. Heat or thermal energy is by far the more abundant resource. To put it in perspective, the thermal energy in the uppermost six miles of the Earth's crust amounts to 50,000 times the energy of all oil and gas resources in the world! The following are technologies that have been invented to use geothermal energy to produce electricity:

  • Geothermal electricity production: Generating electricity from the earth's heat.
  • Geothermal direct use: Producing heat directly from hot water within the earth.
  • Geothermal heat pumps: Using the shallow ground to heat and cool buildings.

Biomass (Bioenergy):

Biomass or bioenergy is the energy from organic matter. We have been using it for thousands of years, ever since people started burning wood to cook food or to keep warm. And today, wood is still our largest biomass energy resource. But many other sources of biomass can now be used, including plants, residues from agriculture or forestry, and the organic component of municipal and industrial wastes. Even the fumes from landfills can be used as a biomass energy source. Bioenergy can be used to provide heat, make fuels, and generate electricity.

Because they come from organic matter, biomass resources are renewable. For example, many biomass resources are replenished through the cultivation of fast-growing trees and grasses. As these trees and grasses grow, they remove carbon dioxideča major greenhouse gas-from the atmosphere. This is important because bioenergy, like fossil fuels, can produce carbon dioxide. However, the net emission of carbon dioxide from bioenergy will be zero as long as plants continue to be replenished.

Hydroelectric:

Flowing water creates energy that can be captured and turned into electricity. This is called hydroelectric power or hydropower. Hydropower systems use the energy in flowing water to produce electricity or mechanical energy. Today, small hydropower projects offer emissions-free power solutions for many remote communities throughout the world-such as those in Nepal, India, China, and Peru-as well as for highly industrialized countries, like the United States.

A small or micro-hydroelectric power system can produce enough electricity for a home, farm, or ranch.