While there is no doubt (apparently) between both politicians and experts that world needs more energy from renewable energy sources, in order to avoid the dependence on fossil fuels that have negative impact on environment by causing global warming and climate change, so far very few people believed in the potential of geothermal energy as one of the leading renewable energy sectors, especially in United States. But things are starting to look more brightly for geothermal energy because many new investors and it seems like geothermal energy isn't anymore underdog in renewable energy sector.
Growth in geothermal energy sector in the last few years, and different new technological innovations have done a great deal to sudden enthusiasm for this renewable energy sector. This sudden enthusiasm is encouraging faster rates of conventional development as well as interest in new technologies that will greatly expand the amount of exploitable resources, giving additional boost to geothermal energy sector.
United States have 2,957 megawatts (MW) of capacity online today, which makes U.S. the global leader in geothermal capacity. Although capacity looks good geothermal energy sector still represents an almost negligible energy ratio compared to dominant fossil fuels. There are plans according to which in the next 5 years or so, the industry will add around 3,979 MW of capacity that would be enough to more than double existing capacity.
Focus is especially on large-scale, high temperature engineered geothermal systems (EGS), but smaller, more quickly deployable modular units are also showing signs of rapid expansion, as geothermal energy attract more investors not only in US, but worldwide also. EGS have significant advantage over traditional projects by using the heat from rocks deep beneath the earth's crust instead of just using hot water close to the earth's surface like the old geothermal systems use to do. By drilling into these hot rocks and cycling water through the bore hole to create steam and run a turbine, developers can create an “artificial” resource. If developed, these engineered resources could create an exponential increase in U.S. geothermal capacity.
One of the latest major investors in geothermal energy sector will be the web giant Google that announced that it would invest US $10.7 million in the EGS in order to additionally boost US geothermal energy sector.
However story with EGS is still not fully told, there is this undoubted great potential that these geothermal projects have, but it will take some time for further development before these innovative EGS projects become competitive on commercial scale. The main problem so far with cost-effectiveness is the fact that bore holes need to be very deep in order to access rock with temperatures high enough - in some cases up to a mile and a half, which makes conventional drilling technologies inadequate.
There has been some companies, most notably «Potter Drilling» that started using a thermal fragmentation technique called “spallation” for EGS projects. This technique isn't new, and has been used by the rock quarry industry for many years now. Instead of relying on drill bits, which typically only last around 200 feet in hard rock, the company uses superheated water to carve through the earth, because the deeper the drilling, the more difficult it is to drill. According to current estimations spallation can significantly reduce the cost of drilling.
This technique is still not ready for field action but latest financial injection from Goggle worthy over $4 million should accelerate commercialization of this technique. Given the estimation how EGS should be commercially viable within the next five years geothermal energy sectors looks to be heading to a bright future, as one of the leading renewable energy sources with great potential for use in years to come.