Geothermal as a Green Energy Source

We have the technology to do a lot of things and one of these is to tap the earth’s energy. This is exactly what we do when we use geothermal which happens to be a green energy source.

Image via WikipediaGeothermal energy is energy obtained by tapping heat from the earth itself. This comes from magma and the radioactive decay of uranium, thorium, and potassium.

The downside to geothermal energy is the fact that it can be expensive to harness. On the other hand, because the earth's crust continuously decays replenishing the heat, it is still a renewable source of energy.

There are three types of geothermal plants. These are namely dry steam, flash, and binary.

Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine that spins a generator.

Flash plants take on water at temperatures over 200 °C out of the ground, and allow it to boil as it rises to the surface, then separate the steam phase in steam/water separators which runs the steam through a turbine to generate electricity.

Last, you have binary plants. Here, hot water flows through heat exchangers and that boiling organic fluid is what spins the turbine.

Once power is generated, the condensed steam and remaining geothermal fluid from all three types of plants are injected back into the hot rock to pick up more heat.

Geothermal plants are operational in several different parts of the globe. These are usually located in geologically unstable parts of the planet. You can see some in Chile, Iceland, New Zealand, United States, the Philippines and Italy. At home, two most prominent areas for this are in the Yellowstone basin and in northern California.

Aside from digging deep into the earth, there are some who believe we can generate power from hot dry rocks. You have to dig 3 kilometers deep first to find these hot underground radiogenic granite rocks. Right now, some Australia companies are exploring this technology.

Image by lydurs via FlickrIf you were to compare the amount of energy collected from geothermal to solar, you still get more from the sun. Despite that, many people may still find a use for geothermal energy at times, since solar energy cannot be harnessed when the clouds block the sun’s rays from reaching the solar panels.

Geothermal energy is a green energy source just like wind, hydropower and biofuel because it is renewable. By maximizing its potential, we don’t have to worry as much about the price of oil spiking in the world market.

But that is not the only thing we should be concerned about. We should also do our best to protect the environment, given that coal fired and nuclear power plants produce harmful gases and radioactive waste that may cause harm to people and the surrounding areas.

Everyone knows that our planet has changed due to global warming. For us to do our share to protect the environment now and for generations to come, we have to learn to use alternative energy sources, and geothermal is another of the many green energy sources currently available.

Resources for Alternative Energy

There are many different forms in which alternative energy is available.

Image via WikipediaOne of these is solar power. Solar power is driven by photovoltaic cells, and these are progressively getting less expensive and more advanced. Solar energy power can be used for electricity, heating, and making hot water. Solar energy produces no pollution, as its input comes completely from the sun's rays. However, much more work still needs to be done in order for us to economically harness the sun's energy. For the time being, the resource is a little too conditional—storage batteries are needed to be used as backups in the evenings and on inclement days.

Wind energy has become the most-invested-in (by private investors and governments together) alternative energy source for the time being. The great arrays of triple-bladed windmills are being placed all over as “wind farms”, to capture the motion of the wind and use its kinetic energy for conversion to mechanical or electrical energy. Of course, there is nothing new about the concept of a windmill for harnessing energy. Modern wind turbines are simply are more advanced variations on the old theme. Of course, the drawback to wind energy is...what do you do when there is a calm, still day? Needless to say, during these times the electric company kicks in for powering your home or office. Wind energy is not altogether independent.

Image via WikipediaHydroelectric energy is available as a source of alternative energy, and it can generate a substantial amount of power. Simply put, hydroelectric energy uses the motion of water—its flow in response to gravity, which means downhill—to turn turbines which then generate electrical energy. Needless to say, water is ubiquitous; finding sources for driving hydroelectric turbines is, therefore, not much of a problem. However, hydroelectricity as a source of alternative energy can be complicated and expensive to produce. Dams are often built in order to be able to control the flow of the water sufficiently to generate the needed power. Building a dam to store and control water's potential and kinetic energy takes quite a lot of work, and operating one is complex as well,and conservationists grow concerned that it. Of course, a dam is not always needed if one is not trying to supply the electrical needs of a city or other very densely populated area. There are small run-of-river hydroelectric converters which are good for supplying neighborhoods or an individual office or home. 

Probably the most underrated and under-appreciated form of alternative energy is geothermal energy, which is simply the naturally-occurring energy produced by the heating of artesian waters that are just below the earth's crust. This heat is transferred into the water from the earth's inner molten core. The water is drawn up by various different methods—there are “dry steam” power plants, “flash” power plants, and “binary” power plants for harnessing geothermal energy. The purpose of drawing up the hot water is for the gathering of the steam.  The Geysers, approximately 100 miles north of San Francisco, is probably the best-known of all geothermal power fields; it's an example of a dry stream plant.