Hydropower potential at existing dams in the State of Minnesota

Abstract

The study identifies existing dam sites in the State of Minnesota which may be economically feasible for hydropower development. This is accomplished in a three step process. A first stage screening uses existing information on the 853 Minnesota dams and a rule-of-thumb criteria to eliminate sites with no hydropower feasibility from further investigation. A second stage screening improves the compiled information on the sites not eliminated in the first stage through site visits, contacts with government agencies, and contacts with dam owners. The final stage of the analysis is a pre-feasibility study on each of the dam sites not eliminated from consideration through the two screening processes. Guidelines for hydropower project cost estimates are developed and incorporated into a computer program which also uses hydrologic and hydraulic information and information on any existing hydroplant to determine the optimum plant capacity for economic return. The financial and economic feasibility criteria chosen are those typical of a municipality. The sites are ranked in order of economic return, based upon the· benefit-cost ratio after 35 years of operation. In addition, each site is given a qualitative ranking of very good, good, marginal or poor feasibility. The very good, good and marginal sites amount to 165.7 MW of additional undeveloped hydropower potential in the State of Minnesota. These sites may generate an additional 581 GWH of electricity per year. The total cost to develop these sites is estimated to be 255 million dollars (1982 base year).