Sustainability at CSB/SJU

Wind as an Energy Source

Greener Energy: The Case for Wind Power at SJU and CSB

Wind is the result of the sun's action on the atmosphere and the land. It is intermittent, varies from location to location, yet it has great energy potential. According to a 1992 Union of Concerned Scientists' (UCS) study, the Midwest offers an abundance of strong winds and Battelle lab estimates that the U.S. could supply up to 27% of total 1990 electricity consumption and about 10% of the total U.S. energy consumption with wind power. (Gipe, p.462) Western and southwestern Minnesota have strong wind power potential. The Buffalo Ridge area alone (800 square miles), for example, is estimated to be able to supply half of Minnesota's 1990 energy consumption. (Gipe, p.462)

Wind is not like a seam of coal or a lump of uranium. It does not stay put and its quality varies. What makes wind power different from dominant power sources such as coal-fired plants is that wind does not always blow when it is needed nor does it always blow with enough strength to produce electricity efficiently. This is why picking the right site and testing wind speeds are quite important.

Though expressed as an average of miles per hour or meters per second, it is the power in the wind that determines the wind's quality as a fuel for electricity production. The power present in the wind is a function of the cube of the wind's speed, so the greater the number of hours per year with high winds, the higher the average annual wind power. Though the average annual wind speed one sees on wind resource maps is not necessarily the best indicator of how a wind turbine will perform, average annual wind speeds are still a good first indicator of wind resource quality. Wind resource maps classify areas by wind class which is defined by a range of wind power densities at a given height above the ground (one should note that the higher the turbine, the greater the wind power).(see table 1 in Appendix A for a wind power classification chart)

Wind Resource Measurement at SJU and CSB

In May 1995, the College of Saint Benedict and Saint John's University were awarded a $10,580 grant from The Charles A. and Anne Morrow Lindbergh Foundation to conduct a wind speed testing study on their two campuses, to integrate the study of wind power into the curriculum, and to see if wind power on both campuses is economically viable.

In collaboration with Northern Alternative Energy, Inc. (NAE), and with consultation with the Abbey land committee as well as the Design Committee, the colleges sited and installed anemometers on each campus. The CSB site has been collecting information since November, 1995 while the SJU site started collecting data in February, 1996. Presently, data are being collected from several test sites on the two campuses (one site at CSB and three sites at SJU). The data are available on CSB and SJU's Web site (http://www.csbsju.edu/environment/wind/). Spreadsheet data files can be downloaded into Lotus 123 or Excel and used for class purposes. The data being collected from the anemometers include wind speed distribution, average wind speed by hour and day, expected energy, as well as other pertinent information. Wind data for the two college campuses are reported in Appendix B. Table 2 in Appendix B includes the average wind speed by month for SJU and CSB, while Charts 1 and 2 include graphs of this data for SJU and CSB, respectively. The anemometers highest in altitude indicate an average wind speed of 12.4 at SJU and 12.8 at CSB.

CSB and SJU, located in a less energetic wind resource area (Central Minnesota) could be classified a weak class two wind resource according to our data and if our collected data are representative of other years. Ron Nierenberg, consulting Meteorologist for NAE, used our data and after adjusting for proximity to trees and the radio tower, concluded St. John's has an adjusted mean wind speed of 14.2 mph which registers as a solid class two. This study later shows that this resource is sufficient to economically install a sizeable turbine. This average wind speed corresponds roughly with data from the Department of Public Service's Wind Resource Assessment Program that show other sites with comparable elevations and distances from Collegeville ranging from 40 to 85 miles to have average yearly wind speeds of between 12 and 13 mph.