Geothermal energy is practical, economical and environmentally cleaner than other forms of energy, a U.S. panel led by experts from the Massachusetts Institute of Technology (MIT) reported Monday.

The study was sponsored by the U.S. Department of Energy and is the first in about 30 years to take an in-depth look at the potential for extracting heat from rocks below the Earth's surface.

"We've determined that heat mining can be economical in the short term," said panel head Jefferson W. Tester, a professor of chemical engineering at MIT.

It could provide a significant amount of the U.S. electricity now being generated by fossil fuels, hydroelectric power and nuclear plants.

Enhanced geothermal system technology has already been proven, and will get better, Tester said. In essence, geothermal power is a kind of heat exchanger, where holes are drilled into an area of hot rocks, and hot water or steam extracted that could run electric generators on the surface.

The panel concluded that the environmental impact of geothermal developments is "markedly lower than conventional fossil-fuel and nuclear power plants."

Government money needed

However, the report points out some potential problems. For one, it said the U.S. government must pay for engineering research and development to reduce the risks so early adopters will invest in geothermal plants.

In particular, research is needed to show that the technology is scalable — can work in a variety of sizes of operations — and transferable to different geologic settings.

Research to demonstrate commercial-scale systems could take five years, the report said.

Geothermal power requires drilling down 1,500 metres in the U.S. West, where the hot rocks are closer to the surface, and much deeper in the East. 

Even so, "the possibility of drilling into these rocks, fracturing them and pumping water in to produce steam has already been shown to be feasible," panel member and MIT geophysics professor Nafi Toksöz said.

But the report warned that extracting water for geothermal plants could be an issue in arid regions, and there are potential seismic risks.

In advocating for geothermal energy, the authors point out:

• Fossil fuels are becoming more expensive.
• Imported oil and gas raise security concerns.
• Burning fossil fuels adds to the amount of carbon dioxide and other pollutants in the air.

The Canadian picture

As of last year, Manitoba claimed to be the geothermal leader in Canada, with between a quarter and a third of all the geothermal system installations in the country.

That includes 21 schools that use a geothermal system to help heat or cool the buildings.

A government spokesperson said last year that the province was considering geothermal options for all new school construction in the province.

In the Canadian experience, geothermal systems are expensive to install but produce virtually no greenhouse gases and can cut annual heating costs by up to 70 per cent.

Alberta developer Frank Kernick said last year that it would cost $20,000 per unit to install ground source heating in a Canmore development, but "I believe there will be a payback in the future when gas prices are higher."

The federal Conservatives included geothermal projects in their $1.5 billion renewable energy plan announced last week.