Bemidji State University

GEOptimize completed a district GSHP feasibility study in 2021 for Bemidji State University (BSU) and Otter Tail Power Company. The study evaluated the conversion of 23 campus buildings totaling approximately 1.45 million square feet from a central natural-gas-fired steam and electric chiller system to a district GSHP system, supporting BSU’s commitment to achieve carbon neutrality by 2050.

The feasibility assessment included development of detailed 8760-hour building energy models calibrated with historical utility consumption. Multiple configurations were evaluated, including horizontal directionally drilled ground heat exchangers, vertical boreholes, surface water heat exchangers in Lake Bemidji, and groundwater-based heat exchangers. The study also assessed complementary energy efficiency measures, including energy recovery ventilators and lighting upgrades, to reduce heating and cooling loads and optimize system sizing.

The recommended system concept utilized a district ambient-loop “energy transfer pipe” configuration, enabling energy sharing between buildings and modular, phased expansion. The preferred geothermal source consisted primarily of horizontal directional drilling (HDD) GHXs due to available land area and lower installation cost relative to vertical borefields. The study demonstrated that excluding efficiency measures would increase required GHX capacity and cost by approximately 40 percent, materially reducing project feasibility.