GEOTHERMAL POTENTIAL FOR MAINE

Although wind, solar, and nuclear energy has been touted to replace fossil fuels in America, some of the most powerful and renewable energy that the earth contains lies within the crust, in the form of thermal energy. While Eastern states have lower thermal gradients and subsurface heat flow, geothermal energy can still provide crucial energy to businesses, institutions, and residential homes, especially in the New England area. Despite high initial costs for geothermal energy production due to drilling and implementation costs, long-term costs are comparatively lower than other energy sources due to low maintenance costs, while geothermal production produces minimal environmental impacts. Maine, the field area of this study, like Vermont and New Hampshire, is not a state currently known for vast geothermal production compared to its western counterparts; while not enough thermal energy is stored in the subsurface to allow for hot, igneous or conduction-dominated systems, the state does have the potential to produce energy via hydrothermal systems. Average subsurface water temperature is 50 - 52 °F, resulting in low heat flow; thus, direct-use systems are not common in the state. Thermal conductivity in the state ranges from 1.78 – 4.60 W/ m°K while the thermal gradient ranges from 6.76 – 27.34 milliK/ m. Nevertheless, through small-scale open or closed geothermal systems, Maine private suppliers are able to offer residential homes, universities and other businesses energy-efficient and environmentally friendly methods of geothermal heating and cooling to lessen reliance on fossil fuels. Since Maine imports all of its oil for heating, geothermal systems can be a way to keep the money in the state. This study summarizes the implementation methods and current geothermal systems in Maine and examines costs vs. benefits of having these systems, and also presents an evaluation of Maine’s potential for further energy production using enhanced geothermal systems. The report also aims to provide a basis for confidence that through innovation, all of the United States will be able to produce geothermal energy efficiently and cost-effectively for local consumption.