In our previous article we learnt about the basic concepts of geothermal energy and saw a few amazing facts regarding the same. In this article we will proceed further and study this wonderful energy source and check out its uses in solving our energy crisis.
How is geothermal energy used?
The mantle of the earth (see diagram in previous article) occupies more than 80% of the total volume of the earth and the temperature is nearly 4000 degrees Celsius at its base. Combined with the other layers the total heat content of the earth is nearly 13 * 1024 Mega-joules. Hence you can see the immense potential of the energy available from heat within the Earth.
Yet it is not easy to use this energy for direct consumption and till the nineteenth century, the only manner in which this energy had been utilized on the surface has been by using hot springs for cooking and so forth, which is an insignificant proportion. But things certainly began to change after that, and this energy was started to be utilized by some ingenious people. As early as the first quarter of the 19th century, an Italian entrepreneur started to utilize this energy for industrial use in a place where wood was the only source of heat, thus saving the previous wood to be used for other purposes.
These were only some initial attempts at the individual level aimed at using geothermal energy. The first breakthrough in commercial electricity generation using geothermal energy took place in 1904 when a small plant was set up to convert geothermal energy into electrical power. That was the beginning, and the trend to utilize geothermal energy began to expand globally over the years.
The current installed capacity of geothermal energy has exceeded 10 GW and is growing by the day.
Not all parts of the world are equally suitable for using geothermal energy. You can check out this article for the available geothermal power in various parts of the world. Also there are several advantages of geothermal power plants over conventional power plants as you can find in this article.
You will need to understand about the plate tectonics a bit in order to understand why geothermal energy is not accessible at all places. As you had seen the depth of the Earth can be divided into various layers – the crust and the mantle being the uppermost two layers. There is another term known as lithosphere which covers the crust and a part of the mantle. The lithosphere is made out of several plates which are in continuous motion relative to each other and this gives rise to several phenomenon. We will not study those phenomenon here but it would suffice to note that geothermal energy is naturally available at the junction of these plates because of the seepage of water or gas from the underside from these spaces. Of course, with the advancement in technology, it will be possible to extract geothermal energy from other sources as well.
Where Does Geothermal Energy Come From? – You must have heard a lot about solar energy, wind energy and even tidal energy. All these forms of energy utilize elements above the Earth. But there is another form of energy which is derived deep down within the Earth – Geothermal Energy.