To Geothermal or Not To Geo Thermal

Not a day goes by without one of my customers (on the days I actually have customers) telling me that they would like to add a geo-thermal system to the new home they are building or to the home they already have.  While I value the new interest in sustainable living that has begun to pervade our society, I can’t help but lament how easily such goals get off track.  Geo-thermal in my region, Seacoast New Hampshire, is a perfect example.

Geo-thermal is a wonderful system when used for the right applications, but all too often it is installed without a clear vision of the full picture.  This in part thanks to the Geo-Thermal industry, itself.  Local GT (geo-thermal) installers have marketed the system so well that people who have little knowledge of “green” building are visiting a young store, barely three months open, to share their enthusiasm.  That store, my store ( ), has received such visitors every single day that I have had customers.  Thus I feel obliged each time to support that enthusiasm, while providing a more clear picture of the product as an integral piece of a home.

In a common scenario, the customer coming into my store has an old farmhouse he and/or she has gutted.  They have lots of land to find a good well, and good southern exposure.   The walls have been ripped down to the studs and they plan to install fiberglass batting for insulation, and so on.  There are multiple problems with this plan, but I’ll focus on two.

  1. Geothermal is designed to create energy or specifically, lower the energy demands of a house – a good thing by providing preheated air or water to a heat system.  Iff the house is acting in the exact opposite behavior, rapidly losing energy (i.e. homes with fiberglass), then you have two systems combating with each other.  The energy savings may be a wash, but the cost of the geothermal system will be a big debit.  Ideally, any home building project, focused on efficiency, should first work to reduce the energy demands of that house.  In any home, this means creating air tightness and installing quality insulation among other measures.  In new homes this will include solar orientation.  The amount of energy saved by such measures will often be greater than the energy created (saved) with geo-thermal, without tapping into the ground.

Whether we are talking about Geo-Thermal, PV, and Solar Water, the first step is always to reduce the energy load.  Once a home owner or builder has achieved those efficiencies, then it is worth discussing the renewable.  We have to break free of this 20th Century notion that high tech solutions will always improve our lives.  That sort of 20th Century thinking is what caused the environmental mess we are facing.  As our great grandparents knew too well, the best solutions often rest with simplicity.  Southern exposures.  Air tightness.  Good insulation.  Fewer walls.  Properly arranged spaces.

*Note: All of these renewable mentioned above are great – I may in fact be installing one in my house – but the first steps, the simple steps, are the place to start.

  1. Sustainability and energy efficiency are not always the same thing.  If sustaining the earth outweighs your desire to create energy efficiency in your home, think carefully about how Geo-Thermal interacts with your space.  In some cases, horizontal closed loop systems are a good option and not extraordinarily energy intensive to install.  In other places, such as New Hampshire ( the granite state) and coastal Maine, where we have tons of ledge, vertical systems are extremely energy intensive to install.  By the time your system is in place and you are living in your home you will already have incurred a massive energy debit (usage).  It could take multiple decades to make up the installation energy with your home operation energy savings.  In some cases, the amount of energy saved in the life of a home will never equal the energy (i.e. carbon) used to create the system.  That means, your efforts to help the earth might be more helpful.  If you are considering Geo-Thermal, discuss this with the geo-thermal representative you are dealing with.   Don’t get me wrong.  I think Geo-Thermal is great…in the right applications.  I’m posting this blog today because I fear the problems of misdirected enthusiasm, much of which can be blamed on the industry benefiting from that enthusiasm.  Just remember the impact on the corn community resulting from the ethanol fever we experienced only a few years ago

There are many places where Geo-Thermal is a good option.  In sandy and sedimentary Cape Cod and Central New Hampshire, drilling wells and breaking ground for horizontal systems is relatively low, in terms of energy impact, compared to rocky crowded places such as the Palisades of New Jersey.  Geo-Thermal is especially effective in organized communities that can share a system, thus dissipating the energy debits across a group.  Some extremely large homes have effectively used a multitude of systems, including geothermal, and justified those measure through life cycle energy calculations.  Don’t avoid geo-thermal, just approach it carefully and in the right order.  Get your homes energy demand as low as you can, first, before doing anything.  Here in the seacoast, we have a few great builders to help achieve that.  To name a few Little Green Homes ( ), G. Gendron Construction ( ), J.P. Ware Design ( ), Ridgeview Construction ( ).

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