Heat from the earth
The Advantages of Geothermal Energy
Geothermal energy is renewable, meaning that as long as we don’t pump too much cold water into the earth -cooling off the hot rocks- the energy will just keep on coming!
Geothermal energy doesn’t produce pollution, and at the same time, it doesn’t contribute to the greenhouse effect!
The power stations for geothermal energy don’t take up a whole bunch of room, and because of this, they tend to have less of an impact on the surrounding environment.
Because geothermal energy is energy in and of itself, no outside sources of fuel are needed to keep the power houses running.
Geothermal efficiency offers an even more exciting benefit to the frugal homeowner - once you’ve built the geothermal power station, the energy is nearly, well, free! While it may require a little energy to actually run the pump, you can tap into the energy that is already being produced to handle this task!
The Disadvantages of Geothermal Energy
As numerous as the benefits of geothermal efficiency are, there are still some
drawbacks that you’ll have to face. And these disadvantages can affect any
or all of the three phases of production - pre-production, production, and
you just can’t set up a geothermal power station anywhere you
want. First of all, you’ll need a location that offers just the right kind
of hot rocks. Just any hot rocks won’t do, since some rocks might prove
too strong to drill through. These rocks also need to be within a
reasonable depth to make drilling down to them a feasible option.
Volcanic areas often provide the most geothermal efficiency.
There’s also another risk to consider - sometimes a geothermal site
might, well, literally run out of steam. And when this happens, the
dry spell may last for periods .
When you are drilling into the earth and steam
is able to escape. Hazardous gases and minerals can seep up from beneath the ground,and finding a way to safely dispose of them may prove very difficult and dangerous.
How Geothermal Energy Works
Our planet, Earth, is covered with the thick outer shell called crust, which is made up of many different rock layers and plates whose components keeps on shifting and changing. Under Earth’s crust, there is a layer of hot and molten rock called magma. Heat is continually produced there, mostly from the decay of naturally radioactive materials such as uranium and potassium.
The amount with in the earth’s surface contains 50,000 times more energy than all the oil and natural gas resources in the world. So, due to extreme heat inside the earth these rocks start developing cracks and release energy in the form of water or heat on to the earth’s surface.
To get that heat, water is pumped down an “injection well”. Then it filters through the cracks in the rocks where they are at a high temperature. The water then returns via the “recovery well” under pressure in the form of steam. That steam is captured and is used to drive electric generators.