06
Sep
14

GEOTHERMAL EXPLORATION: BEST PRACTICIES

IGA recently released ” Geothermal Exploration Best Practices” that forms a guide book for many countries involved in geothermal exploration. This guide book was prepared for IFC ( World Bank group) by the leading geothermal exploration company “GeothermEx” and the ownership of the book was transferred recently to IGA Service GmbH through IGA Board. Broadly this guide book is prepared in line with the ESMAP of the World Bank.

The book recommends a seven phase development process for geothermal resources although several countries have less than seven process as these countries have mastered this process for the last several decades. The guide book explains each phase in detail, thus bringing the right process of development, especially in countries that have joined the geothermal group in recent times.

In a recent paper published in “Renewable and Sustainable Energy Reviews” 2014, top fifteen countries that are generating geothermal energy and the CO2 savings from these countries are listed. The amount of CO2 savings through direct application varies from 1.9 billion kg (Finland) to 10.28 billion kg (Sweden). Surprisingly both the countries have no surface geothermal manifestation but the savings are from GHPs! In the same paper levalized costs (capital to unit cost) of conventional and renewable energy power systems are compared. Geothermal stands out!! Oil rich countries like Saudi Arabia, and UAE are looking at renewables to reduce CO2 emissions that is going touch 750 billion Gg by 2020!!. The World Geothermal Congress is round the corner and new data and new technologies will emerge and the total electricity generated through geothermal will be revised. The information is going to be very encouraging and interesting.

In the recent past, due to IPCC mandate, several players claimed to have develop geothermal energy resources evaluation expertise, proposed several projects seeking govt. support for geothermal development. This is true especially in developing countries that have entering in to geothermal development activities. India is one such country where, based on initial reconnoitory reports conducted by national organizations in collaboration with international organizations like UNDP, several companies with no expertise in geothermal, gave tall claims on resource availability. The reconnoitory data was widely accepted till a Indo-Italian bilateral project jointly carried out by IITB and CNR ( Italian Academy of Science) conducted a detailed survey on all the geothermal provinces of India and brought out high quality strong data base on the chemistry of thermal waters and thermal gases of the above provinces and published in reputed international journals and discussed the same in the World geothermal Congresses since 1995. The data has been transferred to M/S GeoSyndicate Power Pvt. Ltd. the company incubated in IIT and now became an independent company based in Mumbai.

The Indo-Italian project followed the guide lines prescribed in the IGA guide book. In Indian literature several numbers have been published related to the potential that has been refuted because the publication lack of sound scientific basis. The heat flow values published during the rconnoitaey survey was not based on bore hole observation!! These data are now revised based on strong data based on bore holes and the values were published in a highly reputed international journals. Heat flow, thermal gradient, water flow in the wells/springs and aquifer parameters are required to estimate the geothermal potential of a province and site that later needs to be supported by exploratory drill holes. With out such investigation the results will be dubious. The stages in establishing a geothermal power plant are 1) Preliminary Survey, 2) Exploration, 3) Test drilling, 4) Project review and planning, 5) Field development 6) Power plant construction and 7) Commissioning and operation. This is like any other exploration methods. IGA is striving hard to bring out documents that will help geothermal scientists and engineers to establish a sound resource base based on strong data base.