The Hidden Energy We Walk All Over By: Mary Beth Gazdziak & Stephanie McKay

What is Geothermal Energy?  Comes from the Greek words “geo” meaning Earth and “therme” meaning heat.  Defined as heat from within the Earth  Renewable energy - water is replenished by rainfall and the heat is continuously produced inside the Earth.

A Look Inside the Earth  Geothermal energy is generated about 4,000 miles below the surface.  Hot temperatures are produced by the slow decay off radioactive particles - a process that happens in all rocks

Earth’s Layers  Core itself has two layers: solid iron core, and outer core of magma.  Mantle: 1,800 miles thick made up of magma and rock  Crust: forms continents and oceans, 3-5 miles think (oceans) and miles thick (continents)

How is it produced?  Geothermal Electricity is generated when hot water and steam from under the earth’s surface is pumped upwards to power a turbine.  The turbine is turned a second liquid, which is heated by the water and steam.  These sources need to be a minimum of 200 degrees Fahrenheit and there are a limited number of geothermal hotspots with accessible regions.

Traveling Underground  As one travels underground, the rocks and water absorb the heat from this magma and create reservoirs for geothermal energy.  These reservoirs are created by magma coming close to the earth’s surface and heating ground water.  All of these resources have heat and water, and are called hydrothermal resources.

 Hydrothermal resources can be spotted on the earth’s surface through geysers, volcanoes, and hot springs  The only way to test if they really exist is the drill deep into the earth and test the temperature underground.  Most active geothermal resources found on “Ring of Fire”

The 3 uses  The three most common uses for geothermal energy are the direct use and directing heating system, electricity generation, and geothermal heat pumps.  Direct use uses hot water.  Electricity generation requires a power plant to use water or steam at a temperate of degrees Fahrenheit, and are usually only located where the reservoirs are 1-2 miles below the earth’s surface.

Continued  There are three varieties of these power plants. Dry Steam Plants use steam directly from a reservoir to turn turbines, Flash Steam Plants, which convert hot water into steam to drive turbines, and Binary Power Plants, which turn hot steam into another liquid to drive the generator.  Geothermal heat pumps are pumps that use stable ground or water temperatures near the earth’s surface to regulate building temperatures above ground.  They use the constant temperatures below the earth’s surface to regulate heating and cooling above it.

Geothermal energy compared to an orphan  “forgotten”  Very few who try to help  Great potential – just needs to be given a chance

Positive  They burn no fuel when generating electricity  release 1-3% of the Carbon Dioxide emissions that a Fossil Fuel Plant does.  Direct use of geothermal energy has almost no negative impact on the environment  Geothermal features like geysers are protected by law and cannot be harmed  They burn no fuel when generating electricity  release 1-3% of the Carbon Dioxide emissions that a Fossil Fuel Plant does.  Direct use of geothermal energy has almost no negative impact on the environment  Geothermal features like geysers are protected by law and cannot be harmed

Negative effects  Triggers earthquakes  Capline - on a good day they experience on an average ten earthquakes, but not able to feel them.  Switzerland- earthquake triggered able to be felt by humans  Could be a problem if you’re near a major fault.

Negative Effects Cont’d  There are high risks  trying to find the reservoirs  Drilling a well costs a lot of money, about two to three million dollars (per well)  Even if a company does hit a hot spot, they will still have to set up some sort of power plant, which will require even more money.  There are high risks  trying to find the reservoirs  Drilling a well costs a lot of money, about two to three million dollars (per well)  Even if a company does hit a hot spot, they will still have to set up some sort of power plant, which will require even more money.