Geothermal energy or harnessing the heat found internally within the Earth is another area we will consider. Geothermal energy occurs when magma is close to the top of the earth and when rocks surrounding it are porous and filled with subsurface water. That water is heated and finds its way to the surface. This phenomenon occurs near the boundaries of tectonic plates. Geothermal energy can also originate near volcanoes such as Mount Vesuvius in Italy, on the Hawaiian Islands and in the caldera of Yellowstone. Geothermal is an old source of energy. The Ancient Romans, Chinese and Native Americans used water from underground springs for cooking, bathing, and heating. However, geothermal energy is also limited by where it can be accessed and where natural features like springs and geysers occur. The United States is the leader in this area. We now use geothermal energy to generate electricity. Reykjavik, Iceland gets 95 per cent of its hot water from geothermal sources.
In the following experiment students will compare the effects of geothermal and fossil fuels on air quality
Activity 6: Geothermal
Objective: Students will observe that geothermal fuel is cleaner than fossil fuel.
Materials: candles, a tin plate to stand the candle in, matches, water, hot plate, tea kettle, small mirror, tongs, pot holder, and mitts.
1. Heat water in the tea kettle.
2. As water boils hold the mirror over the steam. The mirror should fog but remain clean.
3. Light a candle and put the mirror near the candle. Some soot particles from the candle should accumulate of the mirror. Try holding a piece of over the mirror close by.
Students should see that the burning candle left a sooty residue while the steam was clean.