Geothermal handbook: PlanninG and Financing power Generation t e c h n I c a L r e p o r t 2 / 2

F I g u r E 3 . 1 
Key Elements of Successful Geothermal Energy Development
Source | Authors.

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G e o t h e r m a l H a n d b o o k : P l a n n i n g a n d F i n a n c i n g P o w e r G e n e r a t i o n 
rESOurCE INFOrMATION
The previous chapter showed that a geothermal project’s risks are highest in the initial stages, when 
available resource information is scarce. The risk gradually decreases as the resource information 
base strengthens in the process of exploration and development. The country’s government has an 
important role to play in making geothermal resource information available to potential developers and 
investors. At a minimum, the government should keep public records on such geothermal information 
as seismic data (events, fractures, etc.) and deep drilling data (temperature, pressure, faults, 
permeability). Information on groundwater resources is also essential to geothermal development as 
groundwater should not be contaminated with geothermal reservoir fluids and, among other uses, is a 
potential source of cooling water for the power plants.
These types of data are crucial for potential developers and investors. However, credible interpretation 
of such data can only be done by experts in geology, geophysics, and other relevant disciplines. 
In order to make this first layer of information interpretable for a developer considering exploratory 
drillings, a reliable conceptual model of the entire underlying geothermal system (or, at a minimum, the 
field or reservoir under development) has to be available. Such a model allows a better understanding 
of possible reservoir locations and their size and recharge conditions, as well as the location of 
relatively shallow ground water supply reservoirs. The government should make every effort to 
acquire the best geological and geophysical expertise available to obtain and correctly interpret such 
information. 
As discussed in Chapter 2, the exploration and test drilling phases provide crucial data which must 
be updated as results from production drillings become available. Annex 2 illustrates the process and 
value of information obtained through test drillings.
It should also be noted that the owner of the resource may have an inherent interest in introducing 
a positive bias in the information about the resource. The possibility of independent verification of 
geothermal resource information is therefore highly desirable from a potential investor’s point of view, 
and can benefit the geothermal development market as a whole.