THE FACTS OF GEOTHERMAL

The earth is made up of a central core of molten material, this makes up the majority of our planet.     A cauldron of liquid energy is kept in place by an outer crust, which is relatively thin, we live on the outside.  All the activity in the centre causes pressure to build up and as we know to our cost here on Montserrat, the pressure is released as volcanic activity.   Cracks in the crust, are a necessary safety valve but in the process they allow rain water to seep deep underground and this is how GEOTHERMAL energy is born.

Water meeting molten lava produces steam at great pressure and high temperature, which is always seeking to escape.  These hydrothermal lakes, as they are called, are normally thousands of feet below the surface.  Here on Montserrat, where a natural fault has existed for ages, the HOT HOT lake is close to the surface (perhaps 1500 feet down).  This is witnessed by the Hot Springs at the Shamrock Hotel complex.

Normal Oil drilling techniques will give access to this inexhaustible source of super heated high pressure water at temperatures up to 300 degrees C.

How can this energy be exploited here on the island?  By generating electricity through the use of turbines, these devices have been available for over one hundred and fifty years.  All large power stations in the world, no matter the source of energy, use turbines to drive generators.  Geothermal energy is another method of driving the turbine.  The high pressure and temperature water is brought to the surface via bore holes, like those used to provide water from underground in the Belham Valley.  In the mostsimple system, the turbine is driven directly by the ‘steam’, which is then vented to atmosphere.  This wasteful process can be improved by heat exchanger technology, with the spent liquid being returned to the underground lake via a second well to be recharged, thus increasing the overall efficiency and extending the life of the resource.

The remaining process is standard and consists of electrical links to the grid network.  Once up and running, the use of fossil fuel (oil) will be reduced to very low levels, to provide back-up, if and when the load on the system becomes greater than that provided by Geothermal energy.  In Montserrat’s case the initial system will provide more electricity than is currently used.  The aim of the Private sector is to lure clean, green organisations to the island, who have a need for large amounts of electric power.