My home is heated and cooled with a geothermal heat pump – also known as a ground source heat pump. I was sold on the idea of geothermal heating and cooling for the same reasons that I suspect most homeowners are:
- The promise of lower energy costs
- The attractive renewable energy tax credits, which make it easier to come to terms with the rather exorbitant cost
- The belief that this is truly a more environmentally responsible choice since geothermal heat pumps do not rely on combustible fuel
- The “cool factor” associated with owning a geothermal system (This was not a major driver for me, but I do get a warm glow when people are impressed that I have a highly regarded technology in my home.)
I now question (and with good reason) the validity of the first and most significant incentive for purchasing a geothermal heat pump: Lower energy costs.
Energy Performance Not What I’d Hoped
The fact is, the utility costs in my all-electric, Energy Star, LEED-certified, geothermal heated and cooled home is not drastically better than my neighbor’s homes with far less expensive heating and cooling systems. Now, the reasons for that are probably quite complex and have to do with numerous application and lifestyle matters that can make or break the efficiency of any type of heating and cooling system.
But none of those matters came up in that first, fateful meeting with the geothermal distributor. No – that conversation was filled a lot of confusing yet highly persuasive information about why I should choose geothermal, including an estimate that projected a lifetime savings to me of nearly $40K!
Suffice to say the distributor offered a pretty compelling case for geothermal. You may wonder if, after 4 years of living in my home, I find I’m on track for that type of savings.
I’d be lying if I said I thought I was.
The truth is, I suspect there was much in that conversation that would be terribly, terribly misleading to the average homeowner. A building scientist might have called the distributor out on a lot of those details. But neither I, nor most homeowners, go into these decisions with that level of expertise.
I open about this not because I am disappointed or disillusioned with geothermal technology. Rather, I am disappointed and disillusioned with how the industry conducts itself, and I am concerned with the fallout to well-meaning homeowners. Many homeowners will never see the true the advantages of geothermal energy because of misapplications.
Disadvantages of Geothermal Energy Reside in the Industry, Not the Technology
I got a hard dose of reality after the first cooling season in my home. My system needed to be replaced because the original system was oversized—grossly oversized. I went to a lot of trouble to confirm this fact and basically had to go through a six-month arm wrestling match to make those who were responsible bear the expense of the replacement. I eventually won – but not before I got this depressing peek at the dark side of the geothermal/residential HVAC industry.
- The high cost of geothermal systems is not necessarily attributable to the cost associated with installing the ground loop (that is digging or drilling the holes or trenches that make it possible to transfer heat to and from the earth for the purpose of heating and cooling your home). Over the last few decades, it is the cost of equipment, not the drilling, that has skyrocketed, making geothermal cost-prohibitive to most homeowners.
- The cost-savings frequently touted by geothermal manufacturers are generally unrealistic and inflated, partially due to the nuances of how efficiency ratings are calculated. One expert compared these ratings to scoring the fuel efficiency of car based on the car’s performance while coasting down a hill. Sure, the savings estimates are based on mathematical data, but data that isn’t necessarily relevant to real life.
- Manufacturers are more interested in selling more and bigger equipment than they are in the energy performance of your home. This inherent conflict of interest undercuts the homeowner’s chances of getting the best bang for their buck when installing a geothermal system. There are many factors that impact the efficiency of a geothermal system but the manufacturer and/or the installer is typically concerned with just two things: (1) selling the equipment and (2) avoiding callbacks. Neither of these have much (if anything) to do with actual energy performance.
Here’s the funny part. I am still a fan of geothermal technology, as are many of the experts intent on “calling out” the industry for its…. shall we say….imperfections.
The best homeowners can do is be aware. That’s why I implore you to read this article on greenbuildingadvisor.com. If you are considering geothermal you owe it to yourself to get the “big picture” before you dig into your pockets with your fingers crossed.