The Earth's heat, energy with a promising future


In the coming years the world will harness an increasing amount of energy from the heat of the earth. The topic was discussed at this year's World Geothermal Congress in Melbourne, Australia,  an event that takes place every five years, where stakeholders from around the world participate in "five days" of technical sessions that include a large number of papers (in 2010 there were more than 1,000) of science, technology, business and society. According to data presented at the conference by Ruggero Bertani, an engineering and construction expert at Enel Green Power, there are currently 12,635 MW of installed geothermal capacity in the world. This data has significantly increased compared to ten years ago (8,933 MW) and will continue to grow at an accelerated rate in the coming years: capacity is expected to reach a capacity of over 21,400 MW worldwide by 2020.

Italy, and in particular Enel Green Power, plays a fundamental role in this process. Thanks to the Enel Group company dedicated to renewable energy, Italy is in fact the leading country in Europe in terms of installed geothermal capacity and the sixth worldwide – a record based on historical and technological reasons. Italy is the first country to have used geothermal energy for industrial purposes. Over 100 years ago in Larderello, Tuscany, five light bulbs were lit by electricity produced through steam power emerging from the ground. Since then, the area of Monte Amiata has become an important geothermal location at a worldwide level: since 2000, it has been visited by more than 150 international delegations (including Chile, the United States, Indonesia, China, Japan) who have seen firsthand the innovation and sustainability developed by Enel Green Power.

These two elements have led to the achievement of important objectives, both in Italy and abroad. EGP's Stillwater plant in Nevada (United States) is the first hybrid project in the renewable energy field, combining the continuous generation capacity of geothermal energy (binary-cycle, medium-enthalpy) with the peak capacity of solar power.

Medium-enthalpy binary-cycle technology, which is among the most advanced in the world, is also used in the Salt Wells plants in Nevada and Cove Fort in Utah, and the latter has recently won the Energy Innovator of the Year award for its contribution to the development of the sector in the US State, thanks to the advanced technological standards of its wells.

While in the United States Enel's geothermal energy is combined with PV power, in Italy it is combined with biomass energy. A few months ago, EGP launched the construction of a small power plant (next to the Cornia 2 geothermal plant in Tuscany) powered by a short-chain biomass, produced in a radius of 70 kilometers from its location. It is the first geothermal-biomass hybrid system in the world. Enel is successfully developing its pioneering trend: the coexistence of multiple technologies makes it possible to increase the production of renewable energy, using the same infrastructure and making the most of each technology's special features, while reducing the drawbacks resulting from reduced programmability (from sources such as wind and solar power) to a minimum.