Altarock EGS Graphic

So what is this EGS thing Google is talking about? Several deep well bores into a hot strata where the rock would be fractured, water circulated down, through and back up, heat extracted and cycled again. Much the same as the Kiwis have been doing on a small scale.

This is all great. But its still small money, $10 million is but a pittance of the investment that would be needed to make a big difference. It’s a start where government and private investment has been lacking.

But a reality check offers up some gaps that other efforts have turned up. Some of the most promising renewable projects “stack” processes so getting to the desired end product. Innovation, “clean sheets of paper” and other thinking need applied.

Geothermal is about heat. Latent heat there for the taking. The answer may not be the trap of simply getting water down and back to make turbines spin, but to get the best, most reliable and lowest cost thing circulating. That might be air or compressed air from a wind turbine. Circulation doesn’t by definition require water. The point is to get the most heat to work with at the lowest cost. That’s where my money would go first, be able to move on a set of wells with the needed circulating material be it a gas or fluid.

The geothermal as in ground source systems applicable for home sized systems are desperately needed and addressed to the average existing homeowner. The single-family dwellings worldwide in particular need geothermal retrofits at low cost. That is what I need, and most of you do too. Home geothermal wouldn’t be about getting “heat” – it would be getting a source of coolness (a heatsink) to exchange into during air-conditioning season or a warmer than ambient atmospheric air source to pull heat from in the heating season.

Millions, perhaps hundreds of millions of dwellings could use a retrofit for ground source geothermal sources. But unlike new construction, the house next door, the street, the utilities are already in place offering seemingly prohibitive barriers to an install. But there isn’t any reason many or most homes can’t be offered a geothermal ground source by shallow directional boring of several tunnels filled with heat exchange tubing and an exchanging medium. As a practical matter, the bores could be near vertical allowing a great deal of subsoil latent heat to be used. It won’t work everywhere, rock or other subsoil condition may make a location impractical, but it’s a sorely overlooked market.

The geothermal reality is going to get a boost from Google. The money for Southern Methodist is to update their geothermal resource maps. Potter Drilling obviously will use the funds for drilling research and Altarock hasn’t said exactly what the Google money will be used for but has closed $26.25 million of private placement investment for developing engineered geothermal technology and projects.

Reality isn’t including much attention from the U.S. government, probably because the constituency of special interests is still too small for effective influence. So the research dollars aren’t there. Ground source heat or heatsink depending on the season for existing buildings doesn’t seem to get attention even as it’s the largest market of all. That’s the one I’m most interested in. Saving on home and business heating and cooling plus hot water are big conservation areas. Innovation here could make a big difference.

Geothermal relies on a red hot glowing ball a few meters to a several thousand meters down in most places on the continents. The continents are “light” rock floating on the heavier hot magma, a massive resource that in most cases should be a nearly endless source of heat energy. The primary know how is in hand, it’s the good sense and using it that isn’t.

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