Obtaining of Geothermal Energy in a Very Unusual Way

geothermalA team of American scientists announced a forthcoming effort to use one of the most powerful energy source provided by nature. We are talking about the geothermal energy. This kind of energy is planned to be obtained through a very unusual method – by pouring water into the bowels of a sleeping volcano in central Oregon. The employees of such initiating companies as AltaRock Energy (Seattle, WA) and Davenport Newberry Holdings (Stamford, CT) hope that the steam produced as a result of this action, will be utilized to get cheap and clean energy regardless of the weather conditions and with no side effects such as earthquakes.

Despite concerns about the possibility of the provocation of earthquakes, several organizations showed their interest in the Oregon project at the same time. The total amount of USD 43 million was allocated for the initial development of the project. It should be noted that the United Stated Department of Energy (its investment makes USD 21.5 million) and Google Inc. (with the investment of USD 6.3 million) are the most important investors. The great try-out of our abilities to bring the geothermal energy to the next level will take place this summer on the slopes of the volcano Newberry 30 kilometers south of Bend, Oregon.

The heat contained in the bowels of the earth’s crust, has been successfully used to obtain energy for about a century. Scientists direct the hot water or steam that expose to the surface, to the rotation of the turbine, which generates the electricity. The trouble is that the unusable sites of such “exposing” become less and less common. The next step would be the use of hot rocks, but they have no cracks, and there is no water to produce steam.

To collect this kind of heat and to convert the geothermal energy into an important source of “green” electricity, the new technology of the “Enhanced Geothermal Systems” has been developed. Deep wells are drilled in hot rocks. Then, water is pumped there. It results in the appearance of tiny cracks in the rock during the process called hydroshearing. The cold water pumped into an underground reservoir via production wells, exposes in the form of steam. However, there are some concerns that this shearing of deep underground rocks may result in earthquakes.

Till now, there have been some troubles, as today only two small plants of this type are operated – one in France and another in Germany. The third plant (Basel, Switzerland) was closed because of possible earthquakes. In Australia, the project died out because of the troubles with drilling. As a result, according to the recently adopted international protocol, developers have to conduct their experiments away from any settlements and the local population must be aware of what is happening.

Nevertheless, the project initiators are concerned about other problem – they want to create a reservoir, which will be large enough to support the operational process of a commercial power plant. During the creation of the new project, the polymer plastics similar to the plastics used in the production of biodegradable dishes, will be utilized. As for the earthquakes, the scientists are sure that the probability of their occurrence in the vicinity of Newberry is very low. This area is a seismic “dead” zone, which is rather far from any settlements to cause any significant harm. Also, in any case, the volcanic ash layered over millions of years will suppress any oscillations. However, the U.S. Department of Energy is planning to control strictly the course of the experiment as well as the operations of the existing geothermal plants in California, Nevada, and Idaho.

The last time the volcano Newberry erupted over 1,300 years ago, even before the last glacial period, but the research that took place in the 1980s, showed that the rocks near the earth’s surface still retained the heat. AltaRock is going to fill the prepared experimental well (more than 3 km deep) with water at a rate of 3,600 liters per minute. Totally, these days the bowels of the volcano will be filled with more than 100 million liters of water.

When released to the soil, cold water fills the existing cavities and creates new ones by cracking the rocks. Then, tiny particles of plastics are injected, and they seal the cracks in the walls of the well hermetically. Thus, they give water the possibility to deepen more and more. The supply of cold water continues, it passes the first level, goes further, and cracks the rock at the bottom of the well. After sealing this level, it results in the appearance of cracks in the third section. Later, the plastics that regulated the distribution of water at the initial stage, just dissolves. Seismic sensors make it possible to create detailed maps of shearing, which is expected to produce a reservoir of cracks at a depth of 1.8-3.4 km from the earth’s surface. At the same time, its diameter will make a little more than 1 km.

A month ago, the U.S. Bureau of Land Management assessed the potential impact of the Newberry project on the environment and found no reasons for its termination. The public comments are received before the issue of the final decision in the coming months. ‘The construction of a full-sized power plant is not proposed yet, but, nevertheless, it can come true in 10 years,’ Doug Perry, President and CEO of Davenport Newberry, said.

If this happens, the geothermal energy will be able to overtake and even surpass its environmentally friendly “colleagues” – solar and wind energies, because it doesn’t depend on the season, time, or weather conditions. According to the assessment of the U.S. Geological Survey dated 2008, the geothermal energy has the potential to provide 50% of the electricity required by all the country (today, its contribution makes 0.3% only). Of course, time will tell us whether the scientists will manage to put it to such a level and whether it will be beneficial from an economical point of view.