Anderson County, Tennessee
Working to promote sustainability and energy independence, ARCADIS helped to bring clean, wind-powered electricity to the Tennessee Valley. The wind energy generated at Buffalo Mountain supports Tennessee Valley Authority's Green Power Switch® program, which provides a choice for consumers seeking cleaner sources of energy that do not create air pollution and helps to sustain natural resources for future generations.
The services ARCADIS provided allowed for the construction of additional capacity at the Buffalo Mountain site – from 2 megawatts (MW) to 29 MW of generation, or enough to power about 3,780 homes.
The Challenge
The Buffalo Mountain site, located atop a four-mile switchback mountain road, originally had three wind turbines generating 660 kilowatts (kW) each. The expansion project added 15 larger turbines, generating 1.8 MW each. The construction of larger, utility-scale windmills posed several engineering challenges, including:
- The wind farm, located on the site of a former coal strip mine, was constructed using towers over 250 feet in height with blades measuring 138 feet long, each.
- Stringent requirements placed on suppliers and haulers to safely transport the tower sections, blades and nacelles up the four-mile mountain road.
- Evidence of mine spoil at the site - in some cases, the spoils were graded to form a benched ground surface.
- Design of a replacement bridge for heavy construction traffic at a stream crossing.
The ARCADIS Solution
The outstanding efforts made by ARCADIS staff members were recognized by the prime contractor of our client, a $4 billion energy-services firm, saying, "I am exposed to many firms providing services similar to what your firm provides. (ARCADIS) ranks as one of the best."
ARCADIS' geotechnical investigation characterized subsurface conditions to determine foundation design parameters for each turbine location. The investigation included:
- Topographic surveys of 10 curves, dips and bumps in the mining road. Based on these surveys, ARCADIS prepared drawings showing the additional cut-and-fill required to allow the special hauling trailers to negotiate the steep, curving mountain road.
- Site reconnaissance, borings, soil sampling, standard penetration testing, rock coring and laboratory testing.
ARCADIS also provided the following services:
- State-of-the-art GPS applications to provide survey control at the new windmill sites and along the four-mile access road.
- Erosion and sediment control plans for modification of 15 culverts along the road route, several involving waters of the state.
Buffalo Mountain signals ARCADIS' first application of its services for utility-scale wind power project developers and contractors. Drawing from the expertise of over 2,200 professionals in 66 offices nationwide, ARCADIS is truly a world-class firm of consultants, engineers and project managers. Discover ARCADIS…Part of a bigger picture.
