Utilizing The Earth’s Heat | Living Planet | DW | 18.05.2004
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Living Planet

Utilizing The Earth’s Heat

In France, renewable energies generate less than one percent of the country’s power. Yet a lesser-known form, called geothermal energy, is being successfully used near Paris.

Geothermal energy harnesses the heat from inside the earth to create warmth.

Geothermal energy harnesses the heat from inside the earth to create warmth.

Chevilly-Larue seems like your average Parisian suburb. But it is actually home to Europe's largest geothermal energy facility.

At the earth’s center, around 3,700 miles below the surface, temperatures can reach up to 5,000 degrees. This heat is transferred to nearby water, which travels back up to the surface through faults and cracks.

The geothermal plant of Chevilly-Larue, nestled between a school and a residential area, pumps the hot water up to its turbines. It then uses the warmth that is still in the water to heat the homes and businesses linked up to its system.

Geothermal energy is a somewhat noisy endeavor. But it is a clean and renewable source of heat and hot water. According to thermal engineer Michel Andres, who runs the facility, this form of energy involves simply transferring water from one place to another.

"So, we avoid any fossil fuel combustion and any polluting gases or emissions, which means you don't contribute to the greenhouse effect," Andres explains.

Useful energy, but with shortcomings

It's estimated that the presence of this geothermal facility reduces carbon dioxide emissions by 40,000 tons every year and nitrogen oxide emissions by 70 tons.

Plants like this one are most effective in an urban context, in places with a high population density. The further away the final destination, the more expensive the power.

Tour de France Atomkraftwerk

These cyclists riding past a nuclear-powered station outside Saint-Vulbas could breathe in clean air if more geothermal power was used in France.

Francis Sorin, information director for the French Society for Nuclear Energy, says geothermal energy is useful, but has its shortcomings. “This kind of power is sometimes difficult to extract, so it costs a lot,” Sorin says.

A further problem is that it cannot provide large amounts of electricity, he adds. “It can fulfill local needs, but obviously not national ones.”

A costly undertaking

Geothermal energy does require a lot of investment. The construction of the water extraction plant and the water distribution network is the most expensive. Once that is completed, extracting the heat costs very little.

Therefore, to make the facility economically viable, you have to have many customers in a small area. With nearly 18,000 homes or offices linked up to its network, the facility in Chevilly-Larue has been able to develop such economies of scale. But that isn't always the case.

The operators of this clean energy are now seeking political support. This geothermal facility and others in the region are lobbying to get the French government to reduce the value added tax on geothermal power. Currently, the tax stands at about 20 percent. The state electricity company, which sells mostly nuclear power, enjoys a 5.5 percent tax rate.

Geothermal activists argue that a lower tax rate would provide an incentive to get more geothermal units off the ground. And this would offer an environmentally friendly alternative to nuclear power.

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