Imagine being in the middle of a volcanic eruption in Krakatoa, or spray of geyser in the Yellowstone National Park. Hot, right? But why? Just what is the reason that lava exploding out of a volcano and jets of water shooting out from the bowels of Earth so hot?

Well, billions of years ago, our planet, just newly formed, it was literally a red, hot ball of fire, consisting of molten rocks and metals at a dangerously hot temperature. The surface was too fiery and hot, and the young Earth was under a very dangerous condition for life to thrive. For the first billion years, Planet Earth was in such state, uninhabited, burning and glowing continuously, with volcanoes erupting and meteorites crashing onto the surface. Though time has gradually cooled the Earth's surface (the crust) and gave birth to life of its own, the heat that raged the ancient Earth (we call this heat the primordial heat) is still captured beneath the crust. And that heat, in fact, can be turned into useful energy for us – Geothermal Energy.

How does Geothermal Power Produce Energy?

The source of geothermal heat can vary greatly in depth hot-water springs, such as those found in the Yellow Stones National Park, are pretty near the surface of the Earth hot layers of bedrock, or even pockets of magma, on the other hand, can be found as deep as ten miles deep. In order to extract this thermal energy, we use a mechanism called a geothermal heat pump, which extracts heat energy out of the ground.

The most commonly used method is the water-pipe method, which consists of a system of metal pipes that passes through a source of geothermal heat in the ground. Water is poured into one end as water passes through the source of heat, it will turn into steam the expansion of liquid into gas, coupled with the thermal expansion of water, raises the pressure inside the pipe, and the steam will shoot out of the other end.

This steam can be turned into useful energy for us in more than one way. In order to produce electricity, this steam goes straight into the turbine chamber, where the steam?s kinetic energy will turn the turbine and hence the electrical generator. But in most households the steam is used domestically steam can be used to boil water, for central heating, ect. Corporations make wide use of geothermal heat as well – such appliances include sustaining water temperature at fish farms and aquariums, pasteurizing milk, maintain air temperature in greenhouses, and many more.

In Japan and Finland, hot water springs create hot baths – these are called Onsens. These hot baths not only cost no external energy, but the water contains minerals (such as Sulpher) from deep underground that are good for the human body.

Advantages & Disadvantages

Geothermal Energy is energy straight from the ground, and therefore a relatively clean form of energy, with no emissions. It?s also rather renewable the heat energy we are extracting from underground is actually an extremely small fraction of the total heat stored in the Earth, so at our current rate of extraction it will not run out for at least a few millions years. Lastly, it can be used almost anywhere, and all year long too – no matter where you are on Earth, with some fifty meters? dig you will find a source of geothermal heat. In volcanic regions you might have to dig even less – in Finland or Northern Japan, for most parts ten meters of so will be enough.

Let's consider the disadvantages. Geothermal Energy never yields an enormous output like hydroelectric power or nuclear power – indeed, the method of heat-pump can only extract so much heat at a given time, and then again never at a high efficiency. Not only is the initial capita expensive (it costs a lot to drill into the ground and install pipes), but the network of underground heat pipes often have negative impact on the environment, since the heat will gradually wear out the pipes? outer coating (mostly plastic and paint), which will seep down into the bedrock layer and harm it. Lastly, there is always the problem of leakage, disarray, and rusting – all these require repair, which will not only be costly, but stall heat extraction for at least a month.

Case Study

Sources of geothermal heat – i.e. reservoirs of hot water – are located pretty much all around the world, but those close to the surface are typically found in Iceland, Finland, Japan, South Africa, and the Pacific Islands – these are all regions near hot spots or active volcanoes, where the hot magma can heat up bodies of water nearby.

Currently, USA, Finland, and Japan are the nations making the most out of the Geothermal Power Plants. In USA, most of the hot water reservoirs are located on the West geothermal power plants are important sources of energy for states such as Arizona, New Mexico, Colorado, and Nevada. Recently, Indonesia actively pursuits a campaign of making use of her untouched geothermal reservoirs, with the help of Japanese technology.

Area of Research in the Future

With the current mode of heat pumps, the energy efficiency of geothermal energy is relatively low, since energy will inevitably be lost as the heat travels from the magma to the rock to the pipe to the water to the surface. If we could acquire the heat directly from the magma, i.e. without having to use underground water-pipes, then the energy efficiency, as well as the output, would be far greater.

Another major problem with geothermal power is the initial investment in construction. While reservoirs of hot water abound in many LEDCs such as Timor, Papua New Guinea, Ecuador, and Turkey, these nations often do not have the capita nor technology to build power plants. If a new technology of geothermal energy is to be devised, it would also have to be a lot cheaper in order or it to be feasible worldwide. If that is realized, perhaps, some day, we would all be heating our houses and boiling water from energy 'straight off the ground.'

  

Citation of Images

Geothermal power station schematic. Digital image. Eden Project Geothermal Power Plant. REUK.co.kr, 2006. Web. 8 Sept. 2014.

20 plants are still operating at The Geysers. Wastewater from nearby cities is injected into the field, providing environmentally safe disposal and increased steam to power plants. Digital image. Geothermal Education Office, 2000. Web. 8 Sept. 2014.

The Earth's Heat-called Geothermal Energy-escapes as Steam at a Hot Springs in Nevada. Credit: Sierra Pacific. Digital image. Geothermal Energy. Renewable Energy World, n.d. Web. 8 Sept. 2014.

The Earth's Heat-called Geothermal Energy-escapes as Steam at a Hot Springs in Nevada. Credit: Sierra Pacific. Digital image. Geothermal Energy. Renewable Energy World, n.d. Web. 8 Sept. 2014.

Heat Pump. Digital image. Geothermal Basics. EGSHPA, 27 Apr. 2011. Web. 8 Sept. 2014.

Slinky Loop. Digital image. Geothermal Basics. EGSHPA, 27 Apr. 2011. Web. 8 Sept. 2014.

Horizontal Loop. Digital image. Geothermal Basics. EGSHPA, 27 Apr. 2011. Web. 8 Sept. 2014.