Renewable Energy Spotlight

Renewable Energy
As our country's demand for electricity continues to grow, utilities search for environmentally friendly alternatives for producing energy. These alternatives are commonly referred to as "Green Power".

Green power, in its simple form, is defined as electricity that is generated by using renewable energy sources that have minimal impact upon the earth. Two of the more commonly known renewable energy sources are wind and solar. Their popularity is based on the fact that they are naturally produced, have low operational costs, and that they produce electricity without emissions.

Renewable resource generation continues to gain popularity among environmentally conscious customers. Wind energy is one of the renewable energy options with the most technological advances. However, it is still more expensive to produce green power (typically 2 to 5 times more) than energy from conventional coal and natural gas generation facilities.

Noble Hill Landfill Renewable Energy Center
The Noble Hill Landfill Renewable Energy Center began delivering electricity to CU customers in May 2006. Methane gas produced by the City of Springfield's landfill is harnessed at the generator, providing 3.2 megawatts of electricity to CU customers. The joint project uses a previously discarded byproduct to produce energy for the community.

Click the landfill graphic to view an animation of the energy production process.*

Utilizing this renewable energy power source will provide many savings. In addition to being able to provide power to over 2,000 Springfield homes, utilizing the methane gas for generation is equivalent to the environmental benefit of saving more than 83,000 acres of forest, or not consuming 39,000 barrels of oil. For more information, visit the project overview.

CU Research Projects
CU Wind and Solar power research projects, in conjunction with the Missouri Department of Natural Resources, provide research and educational opportunities in Springfield, including renewable energy output data for wind and renewable energy output data for solar.

How It Works
The energy produced from the wind turbine and the solar arrays is passed through an inverter to synchronize it to CU's existing power supply. From there the energy passes through a meter so it can be measured, and is connected directly into the breaker panel serving the electrical requirements of the TecHOUSE. This renewable energy production satisfies only a small portion of the electricity needed for the operation of the building. Consumers considering the installation of supplemental electric generation, including renewable energy, must contact their local utility provider. For safety reasons, measures need to be in place to insure power generated through alternative means does not feed back into the local utility grid.

Output Projections
The anticipated annual energy output for the wind turbine is 17,500 kilowatt-hours (kWh) and 7,700 kWh for the solar panels, for a combined total of 25,200 kWh. This means the wind turbine and solar arrays are expected to produce electricity 20 percent of the time. The units demonstrated were sized for commercial application at a total cost of $130,000. Units installed for home use would be sized and priced accordingly. Based upon the expected output for both the wind turbine and solar arrays, homeowners can expect a lengthy payback period on projected energy savings for a residential application.

Wind Turbine
Our wind turbine is placed atop a 90-feet tower. Each blade is 11.5 feet in length with a rotor diameter of 23 feet. A 7.5 mph wind speed is needed for start-up. Generation begins at 8 mph. The wind turbine needs constant wind above 8 mph to cause rotation of the blades, which in turn spins a shaft connected to a generator, which makes electricity. An external anemometer measures the wind speed and transmits this data to the controller. At 31 mph wind speed the turbine has reached full load and is capable of producing 10 kilowatts. To avoid damaging the turbine, a safety controller automatically tapers the turbine down when wind speeds reach 36 mph.
Solar Panels
Two, 13 feet x 15 feet racks hold the photovoltaic solar panel arrays. One array is stationary and the second dynamically tracks the sun; meaning it moves to absorb the maximum amount of solar energy throughout the day. The size of the arrays and the weather determine the amount of electricity produced.

* requires QuickTime Player. Free download available.