Outlook for Geothermal Energy

A Geothermal source is classified as a rock formation or underground water form that is at temperatures ranging from 20°C to above 300°C. This source is used to heat a liquid, water or otherwise, through a Rankine Cycle (or Organic Rankine Cycle). Typically temperatures over 150°C are used for electrical energy generation, however it is possible to harness lower temperatures in order to also generate electricity.

Geothermal energy is continuously replenished by the earth’s core heat as well as solar energy absorbed by the earth. The amount of resources required to produce electrical energy is also far lower than for coal-fired power stations. At 25 times less CO₂ emissions, as well as using only about 20 l/MWh (liter per megawatt hour) of fresh water, compared to the 1370 l/MWh used in a coal station, geothermal energy seems to be a far smarter and environmentally friendly alternative.

Although there are some concerns as to the amount of Hydrogen sulfide (H₂S) produced per MWh (0,8kg) it is still significantly less than natural gas-fired or oil-fired powerstations (550 kg and 814 kg respectively).

Generating facilities of this nature are typically modular and normally below 100MW. Although smaller in generating potential than a typical coal power station, if one looks at the space to MW ratio, Geothermal energy is almost ten times more efficient than a typical coal or nuclear powerstation.

Unlike South Africa where the majority of hot water is as a result of nuclear decay that heats the water, Argentina has a large amount of volcanic activity. This is due to the Pacific Rim that runs along the coast of Chile, which continually causes activity in the Andez mountain range.

Whilst in South Africa drilling would have to be deep, in Argentina and in neighbouring Chile, it is possible to harness high temperatures at shallow depths. South Africa’s deep levels of mining may however provide a viable way of reaching water of higher temperatures. Coupled with the rising cost of electricity in South Africa, geothermal is beginning to look viable and gaining more interest.

Argentina has implemented a feed-in tariff system for geothermal projects in a bid to drive development in this sector. It hopes to have 8% of it’s energy generation supplied from alternative energy sources by the year 2016 and it is recognized that geothermal holds potential for reaching this goal.

There is currently a 30MW geothermal-plant being constructed in Copahue in Argentina’s province of Neuquén. The project’s duration is expected to be around 3 years and Canadian Company, Earth Heat, have stated that there is potential for expansion. The province has also recently requested investors to bid in exploration for a potential geothermal powerstation in the area of the Domuyo volcano.

Geotermia Andina has signed a letter of intent with Barrick Gold Corp. in order to commence with the development of the “Los Despoblados” geothermal project in the province of San Juan. It is expected that the feasibility study will be completed and procurement of long lead items could begin in the second half of 2013.

Argentina’s geothermal sector may be boosted even further after minister of Mendoza, Rolando Badasso, went on a trip to Iceland. The minister expressed that this form of energy could be extended to the province of Mendoza in the future.

Chile is another country that has invested heavily in geothermal investigation and is estimated to have a 16 000 MW Geothermal generating potential.