More than lattes?

This morning I ordered a soy latte at the local coffee shop. Have you ever watched your ‘barista’ make your latte? They heat the milk by simply blowing hot steam into the liquid until it froths and boils; a very odd process, but tasty results. As I watched the young girl make my beverage, I began to think of yet another use for steam: Geothermal energy.

Geothermal energy has been around for decades, yet is rarely talked about as a true alternative energy source. In an age that obsesses over ‘going green’, one would think more focus would be directed at this power source. Exploration of its history and plethora of uses reveals a wonderful possibility for the American – and world – energy sector.

The Greek word ‘geo’means earth and as many know, ‘thermal’ means heat. Putting this together, we see that geothermal energy comes from the earth’s heat. The process involves harnessing the heat and steam at the center of the earth to heat and cool buildings or generate electricity. This heat comes from the very core of the earth – about 4,000 thousand miles below the surface, a place that is hotter that the surface of the Sun.



One of the great benefits of geothermal energy is the sources availability. Unlike fossil fuels, biofuels, or other sources, geothermal energy is available 24 hours a day, 7 days a week, and 365 days a year! Also, while hydrothermal energy is focused in certain areas, the earth’s heat and energy can be harnessed ANYWHERE.

There are three main uses for geothermal energy, each of which we will explore a bit:
1. Direct use and district heating system: hot water from springs or reservoirs.
2. Electricity Generation: creates energy from extremely hot steam or water, about 300 or 700 degrees.
3. Geothermal Heat Pumps: heats and cools buildings using the stable temperature of the earth

DIRECT
The direct use of geothermal energy involves using the hot water and steam from springs and reservoirs. History shows that ancient Romans, Chinese, and Native Americans used this hot water to cook and bath (hopefully not at the same time). When one thinks of hot springs in America, Yellow Stone National park frequently comes to mind and it is important to note that these national parks are protected by law and cannot be disturbed.
Modern direct uses of geothermal energy involve piping the hot water from the earth into buildings and a heating system (or through sidewalks to melt snow!).

ELECTRICITY GENERATION
Electricity generation from the earth’s energy is commonly called ‘hydrothermal’ power because it involves directly using the earth’s hot water. Wells with a depth of one to two miles can be dug, or power plants can be constructed. A hydrothermal power plant looks something like this:




The United States uses more geothermal electricity that any other country, yet our use of this power still only accounts to about 1% of our electricity power. California contains 33 geothermal power plants, Nevada contains 15, and Hawaii and Utah each have one plant.
As you envision these power plants, you may question the environment safety of this process, but do not worry! These power plants use no fossil fuel and emit about 1% of the carbon dioxide of a fossil fuel plant.

HEAT PLANTS
The upper 10 feet of the earths stays as a constant temperature of about 50-60 degrees, making it a perfect source for heating and cooling buildings. Harnessing this constant temperature is a perfect way to adjust building temperatures and is extremely energy efficient. In fact, the Environmental Protection Agency calls geothermal energy the cleanest, most cost effective, and most energy efficient means of temperature (www.epa.gov ).

As the world looks at alternative energy sources, perhaps its time we start looking down…. That is, at the earth it self. Just a quick glance over the wonderful possibilities reveals a hope for cleaner energy through the harnessing of steam and hot water.
Maybe Starbucks has been onto something all along.


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Sources:
www.epa.gov
www.eia.doe.gov
www.dictionary.com
www.wikipedia.org

Photos From:
http://www.eia.doe.gov/kids/energyfacts/sources/renewable/geothermal.html