Wind Power at Gustavus

December 2004

A Brief History:

• In the early 1990’s, a study was done to determine if wind power was feasible at Gustavus. It was determined not to be feasible at that time.
• Wind power has become one of the cheapest sources of renewable energy. At ~$0.04 per kWh, it is almost the same as conventional sources.
• There is a lower limit of 7 mph that a turbine must have to produce energy. This is down from 12-15 mph, and efficiency continues to climb with new turbine designs.
• Due to the rising costs of oil and the improved technology of wind power, in May 2001, several professors decided to start a joint research project between the Physics, Geography, and Environmental Studies programs. This project has been going on continuously since June 2001, and will continue indefinitely.
• In October 2003, the Minnesota Commerce Department installed a 50 m monitoring tower on campus.

Current Situation:

• Since June 2001, data have been collected at the soccer field station with wind speed at 10 m height.
• In addition, since March 2002 data have been collected at the Community Garden, Interpretive Center, and two sites in the bean field west of the arboretum (at 10 m).
• Since October 2003, data have been collected at five heights above the bean field using the 50 m monitoring tower.
• The data from the 10 m anemometer on the tower is being correlated with the data from the other stations, with good agreement with the north bean field station and the soccer field station. Wind shear analysis allows us to calculate the wind speed at other heights for all of the sites for which we have 10 m data. Power curves for several wind turbines allow us to calculate energy production.
• Results for 1650 kW turbine at 80 m hub height show annual trends (lower production in summer months):

• Since May 2004, data has been collected at a height of 20 m at the Dutton farm, approximately 1.0 mile west of campus and approximately 100 feet (30 m) higher
• These data have been compared with those from the tip-up tower, correlating well with the 40 m anemometer or lower, depending on the wind direction. This seems to indicate no particular preference for the site at a slightly higher altitude.

• Monthly production calculated to be between 200,000 and 500,000 kWH
• Total annual production of nearly 4,000,000 kWH (with 1650 kW 1-speed turbine)
• Gustavus’ Current annual consumption is greater than 15,000,000 kWH for a total cost of approximately $950,000.

• If we could use all of the energy produced, we could save approximately $126,000 per year (at $0.0315 per kWH).
• If we sold the electricity at $0.02 per kWH, we would make approximately $80,000 per year.
• Cost of turbine installation would be approximately $1.00 /W ($1,900,000 for 1650 turbine)
• Annual Maintenance costs are estimated to be approximately $10,000 per year

Recently we compared Gustavus’ energy consumption to turbine production for the first three months of 2004 (minute by minute data provided by the City of St. Peter). We found that we would have produced approximately 27 percent of our need, and occasionally produced more than we used. This resulted in a minor lowering of our peak demand, about 2%.

Issues:

• Site selection
• Choosing turbine
• Legal ramifications
• Grant Opportunities
• Negotiating contracts, etc.