Geothermal Cost Considerations

One of the systems we have been considering is geothermal. Basically, a geothermal system involves a series of underground pipes through which water is circulated and naturally heated, after which it is transferred to a heat exchanger to concentrate the energy and heat a home. In the summer, the process is reversed so that a house is cooled, rather than heated. (This is an overly-simplistic explanation; I plan on doing more research, just to satisfy my curiosity if nothing else.)

There are a number of reasons right off the bat that a geothermal system seems advantageous - especially because out where we will be building, natural gas hookup is not available. Propane is expensive, and will only go up in cost; plus I've never been very keen on the idea of having a big tank of propane outside of my house. Also, since we will have to drill for a well anyways, why not go ahead and drill/dig for geothermal as well? Plus, it's "green" and a pretty hot thing right now. Seems like a no-brainer.

However, there are some important cost considerations. Most obvious is the upfront cost of installing the system, which is quite expensive. Next, and perhaps even more importantly, is the ongoing cost to run the system - some of the numbers we were getting from vendors about how much electricity it takes to run the system were downright staggering. We also got some conflicting information in this regard - so this point in particular requires much more research.

Another consideration is the infrastructure of the heating/cooling system inside the house - but we'll focus on that in a subsequent post.

In the meantime: Have any of you done much research into geothermal, or perhaps have a system installed already? What have you found with regards to the electricity consumption required to power the system?