Carleton's Second Wind Turbine
Carleton built its second wind turbine in 2011, thanks to a generous grant from environmentally-minded alumni Richard and Laurie Kracum (both '76) that the Star Tribune nicknamed a "400-foot-tall anniversary gift." After a three-year process of gaining approval from the Northfield City Council, searching for a location that was compatible with zoning regulations, and finding a company to build the turbine itself, the turbine was fully assembled in September 2011 and dedicated on October 21, 2011. The turbine is expected to produce 4,000–5,000 MWh of electricity per year, serving more than 25% of the campus electric load.
The new wind turbine will provide power directly to Carleton’s electrical grid. The turbine is expected to produce 4,000 - 5,000 MWh of electricity per year. With a footprint of less than one-quarter acre, the new turbine will serve one-third the annual power needs of nearly 2,000 full-time students plus hundreds of staff and faculty with energy that need not be mined, processed, stored nor transported across the country. This project reduces Carleton's carbon footprint by approximately 10 percent.
The turbine is located approximately 1/4 mile southeast of the Carleton College Cowling Arboretum on an agricultural parcel, adjacent to Minnesota Highway 19 and about one mile east of the Carleton campus and the Northfield city limits. The location was chosen due to its superior wind strength and elevation, close proximity to campus, and minimal impact on nearby homes, local ecology, and public recreation areas. Transmission lines will be routed along Highway 19 across Spring Creek Road and tie in directly to the campus’ electrical grid. Access to the wind turbine will be provided by a gravel road located on an existing field road off of Highway 19. The site is in Rice County’s Urban Reserve Zone in an area that the City Comprehensive Plan has indicated for “Conservation Development.”
Carleton’s second turbine is located almost exactly one mile northwest from the College’s existing 1.65 megawatt wind turbine, which, when it was erected in 2004, was the first utility grade wind turbine in the country to be owned by a college. Carleton is one of only a handful of colleges or universities nationwide to own more than one utility grade wind turbine.
The new turbine is a General Electric (GE) XLE turbine. Its features include an 80 meter tower height and 82.5 meter diameter blades. The blades ramp up at 3.5 m/s wind to rotate at 14 rpm and the pitch and direction of blades adjusts to maintain constant speed. This map shows how all of the various turbine parts traveled to Carleton. Most came by truck, but one path includes shipping via the Great Lakes.
- Model: General Electric (GE) XLE turbine, 1.6 MW nameplate capacity
- Energy Output: Approximately 4,000MW–5,000 MWh per year, or up to 30–40% of Carleton's annual electricity demand
- Tower/Blades: 80 meter tower height, 82.5 meter diameter blades
- Blade Speed: Blades ramp up at 3.5 m/s wind to rotate at 14 rpm (the pitch and direction of blades adjusts to maintain constant speed)
- Contractor: Diversified Energy Solutions, South Dakota (service provided by local GE technicians out of Albert Lea, Minn.)
- Campus Connection: Turbine connects to campus at the Carleton diesel back-up generators
- Crane: Nearly 1,000,000 lb crane with an approx 350 ft tower
- Growing Trend of College Wind Turbines: College and university wind turbines are part of an effort to reduce campus carbon footprints. UM-Morris held a dedication ceremony for its second wind turbine in September 2011, and Luther College (Iowa) also erected the same type of turbine near its campus in the fall of 2011.