Students at the Mankato State University (MSU) presented on three proposals as part of their senior design projects on 11 April.
The fish farm concept could produce up to five million Australian barramundi per year in 14m long, 3m deep tanks. The Mankato water reclamation plant would provide the tank water, and fertiliser processed from fish waste could be supplied to nearby farms.
The produce concept would see a hydroponic system for lettuce, herbs and other leafy vegetables stored in two two-storey buildings that would employ solar panels and geothermal temperature controls to offset lighting costs.
The reservoir proposal would see the quarry consist of upper and lower reservoirs that could hold up to 1.4 million cubic metres of water. Two Francis turbines would pump water to the upper reservoir in non-peak times. At peak usage, the water would flow back to the lower reservoir and spin the turbines, producing up to 25 megawatts per hour of electricity.
All three options would require significant private investment. The pumped storage hydroelectric system has already attracted interest from power supplier Xcel Energy.