RECC’s Project Produces Green Power at an Abandoned Coal Mine
Rural Electric Convenience Cooperative’s Board of Directors voted to pursue a renewable energy wind project in February 2006, with an initial study of the wind speeds around our service area and the technology available. While central Illinois is not a “prime” wind-speed area, there are some locations with moderate wind speeds that can justify the investment in a wind turbine.
Today’s wind turbines are more efficient than ever, and begin generating electricity in breezes as low as 5 mph. These improvements have expanded the areas where turbines might be located.
A small parcel was identified in Montgomery County that showed higher wind speed than the surrounding land. This property was identified as the former Crown I Coal Mine just east of Farmersville. The abandoned mine’s 14-acre pile of coal tailings, or “gob,” created a hill looming 60 feet over the adjacent fields. This extra height catches more wind currents, making it an ideal location for a large wind turbine.
The “GobNob” turbine, as it’s been named, is indeed a large electricity generator, creating 900 Kilowatts of power at its rated capacity. All of its electricity is fed to the nearby Farmersville substation, and then distributed to the co-op members served from that substation. RECC’s members will receive the direct benefit of all the renewable energy produced by the turbine. To date, GobNob has produced over 10 million kilowatt hours of green energy.
About the GobNob property
The Freeman Crown I Coal Mine was closed around 1980. To protect the surrounding environment, the coal tailings pile was covered with a layer of clay soil in 1991 and planted with a mix of grasses for wildlife cover. In 1995, the land was donated to the Illinois Department of Natural Resources, which has developed waterfowl and upland wildlife hunting on 24 acres of the property.
The DNR has agreed to a long-term lease for the wind turbine, the first of its kind in the state. Only about one acre is actually affected, for the turbine tower and access road. This project ties in with the state’s policy of encouraging more clean, renewable energy production from local sources.
The EWT turbine, made in Europe, is a next-generation turbine, with the blades driving the generator directly instead of using a massive gear box to reduce the generator speed. The AC power produced is converted to DC power and then an inverter produces AC at precise voltage and frequency levels.
This design reduces the size and weight of the nacelle at the top of the 230-foot tower, and means less maintenance since a gear box wears out in a few years.
Each of the three turbine blades is about 80 feet long, and their pitch can be automatically adjusted to catch the smallest breeze. When winds exceed 55 mph, the blades and generator are turned away from the wind to prevent damage to the system.
The GobNob turbine started producing electricity on March 5, 2009. While fine-tuning continued on the control and communications systems, the turbine produced over 178,000 kilowatt hours in March.
Funding for the GobNob Project
Large wind projects are still dependent on financial assistance to make them economically viable. RECC received several grants to help offset the initial cost of about $1.8 million for the turbine system. A unique no-interest financing program created in the Energy Act of 2004,called Clean Renewable Energy Bonds, is being used for the remaining cost
Thanks to the following organizations for their contributions to the GobNob turbine:
- United States Department of Agriculture, Rural Development
- Illinois Department of Commerce & Economic Opportunity
- Illinois Clean Energy Community Foundation
Wind Energy in America
Wind energy is the fastest-growing renewable energy source in the U.S., with over 8,300 Megawatts (MW) of capacity added in 2008. This was an increase of 50 percent in wind capacity, and brings the total installed capacity to over 25,170 MW producing around 1 percent of our electric power. Texas is the number one state in wind energy capacity and Illinois ranks at number eight with 916 MW installed.