Geothermal Energy from Bouillante, Guadeloupe

One important aspect of volcanoes is their heat. Sometimes this geothermal energy can be converted into electricity. The geothermal power plant at Bouillante, Guadeloupe, generates power as follows:

1. Deep within the rock, temperatures are far in excess of 100ºC, causing the ground water to flash into steam if a passage opens towards the surface causing a drop in ambient pressure.
2. The steam rises towards the surface in the artificial wells and is fed into turbines.
3. These, in turn, drive generators which produce electricity (some power is used to pump water from the sea to the powerplant; the seawater is then mixed with the very hot water from the turbines to cool it; the moderatly warm mixture can then be relaased into the environment).

Already in 1986, a 5 Megawatt pilot plant was built. After renovation work concluded in 2004, a minimum of 20 MW has been installed which can generate about 12% of the island's peak demand and 15% in produced electrical energy.

Geothermal Energy from Bouillante, Guadeloupe

This is the pipe system collecting the steam coming out from volcano's depths: How deep do the wells have to be? See next image!

How deep is the well? How much steam is harvested? What is the steam temperature? Why is the well inclined by 30 degrees (towards the volcano)? If the image above is too small use this enlargement.

The pipe in the foreground contains not only steam but also water droplets. Due to mixing with gases inside the volcano they are highly acidic. To avoid damage to the turbines, the steam must first be dried inside the tank behind the group.

This "monster" is the pump which pumps sea-water as a cold source for the heat exchange in the turbine.

Geothermal power plants have also been successfully installed in other volcanic areas, for example, in Larderello, Italy, various sites in Iceland, Hawaii, Japan and New Zealand.