Geothermal Heating

Perhaps one of the fastest growing segments of "renewable" energy is geothermal. Geothermal systems can include the more common passive systems that use pumps to circulate water that transfers the heat of the Earth to heat (and cool) your home as well as those that directly use heated and superheated water to generate hot water or steam, sometimes even spinning turbines for electric production.

The installation of a commercial system that uses high-pressure steam is usually handled by industry professionals and is not of concern to the average homeowner. Most residential applications involve the transfer of Earth-temperature water or that heated anywhere from a tepid teacup to blisteringly hot.

However, regardless of the type you choose, there will be an installation of pipes. Pipes installed in the ground that are made of metal (still the best low-cost conductor) should be of as high quality materials and workmanship as you can find. This will be your largest materials cost in any geothermal project, by far. And they should be, given the already great cost of the excavation.

Excavation is sure to make up a significant portion of a geothermal installation. This not only includes the actual cost of renting the equipment but also, hiring a professional excavator to run it and perhaps even the cost of an environmental impact statement, especially in the case of work near a riparian zone or systems that intake and discharge into a larger body of water. You should also consider the cost of putting your yard or farm back into shape after the digging.

Once installed, geothermal systems tend to be the most inexpensive to operate and maintain, since there are very few moving parts. Pumps are usually located above ground or in an access box so they can be maintained on a regular schedule. Most pumps require a yearly drop of oil or two and can operate indefinitely until actual metal wear (such as occurs on bearings) occurs, as long as they're well suited to the task. Choosing the wrong pump invariably leads to premature failure.

Consulting with an engineer, whether part of a contractor's package or your own, will give your project a much higher chance of success. He or she will be able to tell you (and prove it with math) how much pipe is required for the various system options you have as well as the relative efficiency per dollar invested of each type of system given the characteristics of your soil and the preferred materials.

The key to keeping a geothermal system on time and on budget is to spend your time and effort primarily on the planning stage of the process. Choosing wisely at the beginning of the project will allow you to save time and effort later on. A well-planned system can outlast the home it is built into.

Geothermal Heating |