Buzzword: Earth Energy

What it means. Earth energy is the newfangled name for the time-honored tradition of tapping the earth’s underground energy to heat or cool a building by running various liquids through a network of buried pipes. You’ll often see the term as part of an earth-energy system, or EES.

“Geothermal had always been the name for our earth-energy process, and it was confusing because everyone was expecting to see hot water coming out of the ground,” says Mark Morelli of Santa Rosa, California-based Air Connection, Inc. “Then my company shifted to calling it a ‘GeoExchange’ system, but ‘earth energy’ makes it easier for people to relate to what we do.”

“Earth energy certainly reflects what an EES does, which is to use the heat of the ground to both heat and cool your home,” says Greg Dudley, a sales manager at Earth Energy Technology & Supply in Marietta, Oklahoma.

Why the buzz? As Americans seek alternatives to fossil-fuel-generated energy, interest in renewable energy has grown—Morelli and Dudley report that their businesses have boomed in the past year—as has its profile. Al Gore in mid-July called for Americans to wean themselves of electricity generated by fossil fuels.

Earth-energy systems are one way to decrease our fossil-fuel reliance. In its most-efficient form, an EES takes the form of a ground-source heat pump. Throughout the U.S., the temperature just a few yards below the surface hovers around 55°F. Running groundwater, an antifreeze mixture, or a refrigerant through pipes and into the pump in your home will produce heat for home heating and hot water. Reverse the flow during cooling season, and the system will remove excess heat from your home and cool your indoor spaces. (See the illustration, courtesy of the California Energy Commission, above.)

While EES are not mainstream, people are talking about them. Members of the Consumer Reports HVAC forum, for instance, are discussing earth energy, with posters sharing information and links, like this one to the California Energy Commission’s Web page on geothermal heat pumps.

A typical EES will run two to four times as much to buy and install as a conventional oil- or natural-gas-fired heating-and-cooling system. But given the rising carbon-based fuel prices and the lower annual operating costs for an EES, a system could conceivably pay for itself within a few years in the best-case scenario, according to industry experts. Payback time will vary depending on a number of factors. High costs of electricity and installation (drilling is pricier in rocky soil) and a colder climate will increase how long it takes to break even.

What’s more, petroleum-based polyethylene pipes used in many earth-energy systems are getting more expensive and, and installers are likely to pass on that cost to you. And unlike solar-power systems, earth-energy systems don’t benefit from the wide array of utility rebates and state and federal tax incentives, although the earth-energy industry is lobbying to change that.—Gian Trotta

Essential information: Use the heating and cooling cost calculators on GreenerChoices.org. And look for our special section on saving energy at home in the October 2008 issue of Consumer Reports, on sale and online in September. And watch our video on ceiling fans, right, for some basic energy-saving information this summer.

Comments

[Tim]

The entire science building at my college (a very large building) is heated and cooled using this method. It works very well. And the excess coolant water that can't be pumped backed into the ground is used to irrigate our many lawns. Hopefully we will see these types of systems become more widespread. Geothermal systems tend to be 48-75% more efficient than gas or oil systems (See: http://www.brightfuture.us/new/index.php?option=com_content&task=view&id=98&Itemid=27)

[Glenn]

We're considering a geothermal system for our home and I'd be interested in seeing Consumer Reports rate the companies involved in this growing field.

[Carol]

I would also be very interested in a CRO comparison of geothermal manufacturers and/or products.

[Roy Chambers]

I am also considering a ground-source heat pump (geothermal) system for my home, and came to your web site specifically looking for a comparison of manufacturer's products. Can you tell us if/when a comparison might be available ?

[Win]

I live in Minneapolis, MN (45 degrees latitude N.) and would be very interested in a CR comparison of geothermal products and ‘Air-source’ Heat Pumps that operate at outdoor temperatures down to –30F (gotohallowell.com).

[RANDY BURKEL]

I hope to have an issue on heat punps and what it takes to hook up to an existing furnance system. Please it is a good effeciant whay to heat and cool your home.

[Fr. Noah]

Do you have an reviews of geothermal products?

[Molly]

I will be the 7th person to say I would like to see a Consumer Reports comparison of geothermal heat pumps on the market.

[adam]

this would be something that would be great to see a comparison too. thank you

[Me too]

It's 3:00am and I can't sleep so I naturally came here hoping to find a good comparison of geothermal products & manufacturers. I feel like such a lemming.

[Donna Manley]

We are building a new house and are evaluating a geothermal heat pump option. Unfortunately, we need to make a decision in the next few weeks, so you won't have time to complete a full report by then. I do appreciate this blog, and will poke around the rest of the site for more info and comments. Thank you for starting the conversations.

[kirk]

I would like to see a list of best top worst geothermal systems. As we are going to purchase a system and would appreciate comments re what is the best system (manufacturer of heat pumps)
Thanks kirk

[Linda]

Add me to the list of people looking for CR to do a report on these systems. Its time, Folks!

[Chicago]

I am also considering putting one in Illinois. The only system I am hearing is Water Furnace. Are there others out there or is Water Furnace the leader? My pricing was quite a bit-- at 90K (yikes).

I would love to see some reviews--there is almost no information out there!

[Lisa]

I too am asking the same question as everyone else before me. We recently bought a home and we are being told a heat pump is the way to go and I would like some feedback as to what system is the best for the money. Or what manufactorer's or models to avoid. If you have any info please post it...I'm sure we will all appreciate it!!

Thanks

[Sydnee]

We are also building in SC, month 4, and at the critical phase of choosing our geothermal unit. First crisis, neither our builder or HVAC contractor has put one in a home before and our original quote was off 10K due to poor drilling calculations. First quote based in FHP, 2nd WaterFurance but thru research I also found Econar.
It would be a great help if CR would do an analysis!
We are now looking at horizontal looping versus vertical to save some costs. Anyone have firsthand experience with it?

[Bob Dykman]

I would also like to see some info generated by CR.

[Pat McGrath]

We too are in the process of putting the numbers together for a new home in west TN and I was hoping to find more information on typical cost and model comparisons.

[Martin O'Hara]

Me too! I would really like to see something by CR on geothermal. I live in Washington, DC.

[djburwell]

Consumer Reports. Please rate geothermal units so we can make an informed purchasing decision.