Renewable Energy and Conservation

Energy Conservation

Did you know the average household could cut a third - or even half - of its current energy bill by switching to energy-efficient appliances, equipment and lighting, which use less energy than standard products? Below are ideas on how you can save money and energy.

• Replace standard incandescent light bulbs with compact fluorescent light bulbs (CFLs) and save 75% of lighting costs.
• Unplug electronics, battery chargers and other equipment when not in use. Taken together, these small items can use as much power as your refrigerator.
• Take steps to cut water use such as installing faucet aerators, low-flow showerheads, and low-flush toilets.
• A 5° higher setting on your air conditioning thermostat will save about 10% on cooling costs.
• Always buy ENERGY STAR qualified appliances and equipment - they're up to 40% more efficient.
• Turn your water heater down to 120° or the "Normal" setting when home, and to the lowest setting when away. Water heating accounts for about 13% of home energy costs.
• Reduce air conditioning costs by using fans, keeping windows and doors shut and closing shades during the day.
• Turn off unnecessary lighting and use task or desktop lamps with CFLs instead of overhead lights.
• Enable "power management" on all computers and make sure to turn them off at night. A laptop computer uses up to 90% less energy than bigger desktop models.
• When possible, wash clothes in cold water. About 90% of the energy use in a clothes washer goes to water heating.
• Run your dishwasher and clothes washer only when fully loaded. Fewer loads reduce energy and water use.
• Make sure your dryer's outside vent is clear and clean the lint filter after every load. When shopping for a new dryer look for one with a moisture sensor that automatically shuts off when clothes are dry.
• Test for air leaks by holding a lit incense stick next to windows, doors, electrical boxes, plumbing fixtures, electrical outlets, ceiling fixtures, attic hatches and other locations where there is a possible air path to the outside. If the smoke stream travels horizontally, you have located an air leak that may need caulking, sealing or weather stripping.

Content from: Flex Your Power

Renewable Energy

Renewable energy effectively uses natural resources such as sunlight, wind, rain, tides and geothermal heat, which are naturally replenished. Renewable energy technologies range from solar power, wind power, hydroelectricity/micro hydro, biomass and biofuels for transportation.

Wind Power

This months feature renewable energy technology is wind power.

Wind energy has been harnessed for thousands of years to perform useful work for humans. We have used wind power for transportation, water pumping, and grinding since the time of the ancient Egyptians. In the late 19th century, the Danes began harnessing wind to generate electricity using wind turbines.

People often use the terms windmill and wind turbine interchangeably. However, windmills harness the wind for mechanical power to grind wheat or pump water, while wind turbines use the wind to generate electricity.

Today, modern wind turbines efficiently convert the force of moving air into electricity using modern design principles and high-tech materials. Wind turbines come in many different sizes from small-scale home systems of 5 kilowatts to 15 kilowatts, to utility scale systems ranging in size from 300 kilowatts to 1,000 kilowatts. To take advantage of higher wind speeds and to allow the blades to rotate without interference, wind turbines are mounted on the top of a tower typically 160 feet high. Although there has been some experimentation with vertical-axis wind turbines, most wind turbines have airfoil-type blades that rotate around a horizontal-axis. The blades are designed like the wing of an airplane creating lift when exposed to the force of the wind, which propels the blades around in a circular motion. The wind turbine rotor typically consists of two or three blades attached to a hub. A rotating shaft from the rotor feeds into a gearbox assembly and then into the generator, which converts the mechanical motion of the shaft into electricity. As the wind changes direction, the yaw system allows the wind turbine to pivot so that the rotor spins in a plane perpendicular to the wind.

Understanding the Wind Resource

Ultimately, wind is a form of solar energy. The sun's rays heat the Earth's surface creating temperature differences between the land, water, and air, given their different propensities to absorb heat. This phenomena, in conjunction with the temperature differences that exist between the equator and the EarthÕs poles, creates wind as hot air rises, expands, becomes less dense, and is then replaced by denser, cooler air. In sum, wind can be thought of as the circulatory system of the planet, distributing energy from warmer areas to cooler areas.

The economic viability of wind-generated electricity in a particular location is tied to the amount of wind available throughout the yearÑthe wind resource. A standardized system has been established for classifying the wind resource based on wind power density, a measure in watts per square meter of how much energy is available at the particular site for conversion by a wind turbine. Seven different wind classes have been established, with higher classes corresponding to higher wind power densities. In general, wind classes 3 and above (wind speeds of 11 miles per hour or more) are necessary for producing electricity from wind. For large, utility-scale applications, wind classes 4 and above are preferred.

Economics and Future Prospects of Wind Power

Of all the renewable energy technologies, wind power is currently the most cost competitive when compared to traditional, fossil-fuel-based energy production technologies. In fact, wind power is the fastest growing energy source around the world. The United States now has a total of 2,600 megawatts of installed wind capacity. This is equivalent to about three or four large coal-fired power plants.

Utility-scale wind farms produce electricity at about 4.5 ¢/kWh which makes wind power competitive with fossil-fuel-generated electricity. It should be noted that these economics are made possible by a federal production tax credit of 1 ¢/kWh. Even though wind is an intermittent resource, meaning wind speeds vary from day to day and month to month, wind power can be easily integrated into the existing supply mix, making a significant contribution to our nation's energy supply. Most analysts agree that technological improvements and economies of scale in wind turbine production will contribute to even further cost reductions in the price of wind-generated electricity.

Environmental Issues Regarding Wind Power

Wind-generated electricity provides a pollution-free source of electricity. None of the harmful emissions associated with fossil fuels occur when the wind is utilized to produce electricity.

The main concern regarding wind energy development in many area revolves around siting. In the past, some people raised serious concerns about the swishing noise made by wind turbines and their impacts on migratory bird species. These concerns have largely been dealt with through technological improvements and proper siting.

There will always be, and should always be, places where wind development will not make sense for aesthetic reasons, but environmentally-minded citizens should seek to identify as many suitable wind sites as possible.

Content from: The Northeast Sustainable Energy Association