The Massachusetts legislature is considering passing a bill allowing its utility companies to purchase energy created through geothermal means rather than natural gas. HEET (Home Energy Efficiency Team), a non-profit group based in Boston, is working with Massachusetts utilities to look into the possibility of setting up what they are calling a GeoMicroDistric system. This system would use a series of boreholes for ground-source heat pumps and an ambient water loop that would link to buildings in the district to provide heating and cooling.
Geothermal has been around for a while
There is no question that something needs to be done about the Massachusetts energy system. All of it is aging, and at least a quarter of it needs to be completely replaced. But should it be replaced with a geothermal system rather than the natural gas system they are currently using? Geothermal energy has been around a long time. It has been used for producing electricity as far back as 1913, and new technology is helping it grow. Croatia, just this year, brought Europe’s largest geothermal power plant online. It is powering almost the entire city of Bjelovar in Croatia; a city that in 2011 had over 40,000 residents. So, obviously, it can work.
What is geothermal?
Energy.gov defines geothermal as the following:
Geothermal resources are reservoirs of hot water that exist at varying temperatures and depths below the Earth’s surface. Mile-or-more-deep wells can be drilled into underground reservoirs to tap steam and very hot water that can be brought to the surface for use in a variety of applications, including electricity generation, direct use, and heating and cooling. In the United States, most geothermal reservoirs are located in the western states.
Think Old Faithful in Yellowstone National Park and all the other hot springs found around there. That old faithfulness is one of the major pluses of geothermal energy: it is naturally occurring heat and steam that can be harnessed 24 hours a day, 365 days a week. Unlike other renewables, geothermal energy never stops, never has a lag time. The wind can stop blowing; the sun can stop shining, but heat from underground reservoirs remains constant. On the other hand, a major minus are the natural underground reservoirs: No underground reservoirs, no energy. Those reservoirs aren’t always where you need them. Drilling for them is expensive, and there is no guarantee that drilling for geothermal resources will pay off.
If Massachusetts has geothermal resources right where they need them to be, getting energy from them will be pretty straight forward. Holes will be drilled, much as they are for oil and natural gas, then the steam or hot water will be brought to the surface. Once there, geothermal power plants run essentially the same as coal or natural gas power plants:
- Wells are drilled
- Steam turns the turbine
- The turbine drives the electric generator
- Power lines deliver electricity
Keep an eye on Massachusetts. It might be heating up.