Geothermal Power: Facts About Natural Energy Sources

Image Gallery Aerial view of two harnessed geysers thirty miles from Iceland's capital city of Reykjavik. The water in the foreground is boiling. PHOTO: ANDREW SCHNEIDER

Modern man—that's you and me — is power hungry and, in particular, we just can't seem to get enough electricity. On the other hand, we now know that generating all the electrical power we use — especially when we burn fossil fuels such as coal to do — it is one of today's prime sources of air pollution . . . and that puts us between a rock and a hard spot. How are we going to have power without making the air unbreathable . . . and do we really need to harness all that energy in the first place? 

Many of the environmental groups make a justifiably strong case against our steadily-increasing demands for electricity to run such jimcracks as powered toothbrushes. Still and all, it will probably be some time before we collectively limit our consumption of electrical energy to essentials only . . . which puts us right back in the big middle of the problem. How are we going to generate all that electricity without continuing to futz up the air, land and water?

Well, there are ways and some of them have been around longer than man himself. One which has been largely ignored in this country, although used fairly extensively in some other parts of the world, involves the harnessing of geothermal energy.

Geothermal power — sometimes called magma power — is heat energy taken from the planet itself. As you may know, the core of the earth is molten rock — or magma — and only the thin outer crust of our planet is cool. On the average, for every mile we bore into the earth, the temperature climbs about 113 degrees Fahrenheit. In some areas this temperature rise can be as much as 720° F for each mile we drill and, in the Imperial Valley of California, a jump in temperature of 3,632°F per mile has been recorded in test wells.

Now heat is energy but — to make that energy readily available for the generation of electricity — we need one more ingredient: water. Heat plus water equals steam . . . and, if the ground directly above a hot spot on the earth's crust happens to be porous and filled with water, There will be created a natural boiler. And if this boiler is sealed over by a tight layer of clay, we have — ready made — a tremendous reserve of useable power. That doesn't happen often but it happens often enough and this is exactly the situation that exists in California's Imperial Valley.

Tests there have shown that geothermal wells sunk into the huge natural boiler under the Valley will tap enough live steam to drive generators capable of supplying two-thirds of all California's electrical needs for years and years to come. Furthermore, the steam brought to the surface from that gigantic pressure cooker contains only a two to three percent mineral content and — by desalting the water which condenses from the steam — approximately 5 to 7 million acre feet of water per year will be added to the state's supply.