The study of alternative energy would be enriched by a community application. A community such as a lake resort where the local governing body could begin by drilling the Geothermal start point. This "seed" could initially provide a heat source for communal use much like the commercial application in Universities and Downtown corridors. Insulated and distributed by non-toxic, non-corrosive coolant the system would theoretically require minimal maintenance. Initially, this in and of itself would save many thousands of dollars and tons of ecological irritants. Green communities should be the rule, not the exception!
Called the start point, a Geothermal well is a drilling done to an extreme depth which varies geologically. Ironically, the colder regions may see more shallow wells than more temperate zones. The concept is that the earth will provide millions of renewable MBTU's for thermal exploitation. Ideally, the one-time expense of drilling bestows this and future generations with the benefits of heat and electricity. Technically, a back-up resource would be redundant considering the nature of the source. Further to this is the implication of eco-fuels for recreational craft and vehicular use ensures maximum compliance with nature.
Primarily, the injection of waste water into the geosource provides both steam and waste water treatment. The steam force is used to turn turbines and channeled through a heat exchanger to both distill and recover heat for distribution in coolant. The distilled water may be distributed as potable supply. Technically this represents a closed system be it not for the consideration of deposits.
The injection of the waste water would include solids. These will become separated upon the change of state to steam and must accumulate in the geowell. Good fortune would have the geowell existing as a "pocket" within the earth. The alternative to this being an accumulator before injection and after expulsion. Solid waste treatment then becomes a concern and potentially costing the system of electrical energy.
Individually, the homeowners may employ a "heat banking" system consisting of a gravel pit and glycol medium. This kind of "banking" may be useful in cases of extremes or interruptions. This system is the basis of the isolation of oneself to the "grid", another article I will submit.