A year ago an MIT-led study of enhanced geothermal systems (EGS) was discussed. See full report: The Future of Geothermal Energy (pdf).

Things are progressing.

last week, the DOE tapped Ormat Technologies of Nevada to test MIT's conclusions. To build the nation’s first commercial-scale EGS site and demonstrate its viability to power America.

And not just in regions blessed with bubbling-at-the-surface, energy-rich geysers. But all over.

It may be worth repeating part of that old press release from last year.

the electricity produced annually by geothermal energy systems now in use in the United States at sites in California, Hawaii, Utah and Nevada is comparable to that produced by solar and wind power combined. And the potential is far greater still, since hot rocks below the surface are available in most parts of the United States.

Even in the most promising areas, however, drilling must reach depths of 5,000 feet or more in the west, and much deeper in the eastern United States. Still, "the possibility of drilling into these rocks, fracturing them and pumping water in to produce steam has already been shown to be feasible,"

These technologies are used in current drilling systems for fossil fuels. It's a different application of known capabilities.

There's money chasing EGS.

Meanwhile, the promise of a red hot geothermal future really has analysts and investors buzzing.

The EGS demo in Reno is on its way, thanks to support by the DOE for an agency investment of just $1.6 million. . .

Google has named geothermal development an investment priority in its goal to make renewable energy cheaper than coal. . . It's a short list. Solar. Wind. And now, geothermal.

There are also many small scale applications of geothermal for production of heat and cooling for residences and other structures that simply tap the heat differential between air and ground.

Where does the heat come from?

The planet's internal heat was originally generated during its accretion, due to gravitational binding energy, and since then additional heat has continued to be generated by the radioactive decay of elements such as uranium, thorium, and potassium. . .

Much of the heat is believed to be created by decay of naturally radioactive elements. An estimated 45 to 85 percent of the heat escaping from the Earth originates from radioactive decay of elements concentrated in the crust.

The earth is a nuclear reactor. So to speak. We just need to harness the output.