Grail of grails: Taking deep geothermal to the furthest reaches

In Massachusetts, of all places, a plan is being hatched that would bring deep geothermal development to an area that lacks obvious near-surface development potential: New England.

The company is Atlantic Geothermal, and the plan may be as new to you as it is to us. CLEM, or Closed Loop Energy Mining. Its aim is obvious; to generate clean, renewable electricity, but the concept takes enhanced geothermal systems to the next level.

The company’s web site states that they would like to put a CLEM power station in western Massachusetts. They also appear to be looking for a manufacturing company to take the leap with them and get first dibs on the power produced. But AG has been pitching their plan around New England, and it was a commentary out of a Keene, NH newspaper web site that got our attention.

Here’s how the company describes there concept. First, they note that the industry standard open loop model (EGS) uses fractures in the rock to move the water. These natural or artificial fractures are random at best and limit the size and effectiveness of these systems. Producing massive amounts of power requires moving massive amounts of water and this is often uneconomical on a large scale using tiny fractures in the rock.

The essential change is in the ground loop design and construction. During construction and power plant operation, hydrostatic pressure management maintains structural integrity of the central main shaft. The design uses bore holes drilled into dense hot granite to move water through the ground loop with a central shaft that connects all the bore holes. This creates a ground loop with a shape much like a leaf. The veins and capillaries in a leaf are similar to the main shaft and bore holes of the ground loop. These veins and capillaries can be viewed as a well designed circulatory system, with a pumping station as the heart.

Granite has hit our radar screens in the past, but because of natural permeability. Here, AG does not spell out why they find granite so appealing, and are intent on creating the veins via drilling.

The upshot here is the company believes it can build a 160 MW power plant – which the Atlantic Geothermal refers to as Mega Generation Deep Earth Closed Loop – using the technology, and sell the power for as little as 5 cents per kilowatt hour. Atlantic Geothermal has spent the past ten years focused on the technical design of a deep heat canal and hydrostatic system to deliver an unlimited amount of water for geothermal power. And in March of 2007 the company filed patent applications with the United States Patent Office for the hydrostatic system/canal.

Whether or not the company succeeds even in part, we are impressed by the boldness of the plan and encouraged by their intent to bring geothermal to where deep is a necessity. If they succeed, they will pave the way for the generation of clean electricity in places as yet unimagined and on an unprecedented scale.

We have a number of questions for AG, and have asked for some answers. We will pass along the answers as they are forthcoming and keep a watchful eye on developments in general.