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 2 . 1
Geothermal Project Development for a Unit of Approximately 50 MW
MILESTONES / TASKS
yEAR OF IMPLEMENTATION (INDICATIVE)
1
2
3
4
5
6
7
Lifetime
1
Preliminary Survey
Data Collection, Inventory
Nationwide Survey
Selection Of Promising Areas
EIA & Necessary Permits
Planning Of Exploration
2
Exploration
Surface (Geological)
Subsurface (Geophysical)
Geochemical
Soundings (MT/TEM)
Gradient & Slim Holes
Seismic Data Acquisition
Pre-Feasibilty Study
3
Test Drillings
Slim Holes
Full Size Wells
Well Testing & Stimulation
Interference Tests
First Reservoir Simulation
4
Project Review & Planning
Evaluation & Decision Making
Feasibilty Study & Final EIA
Drilling Plan
Design Of Facilities
Financial Closure / PPA
5
Field Development
Production Wells
ReInjection Wells
Cooling Water Wells
Well Stimulation
Reservoir Simulation
6
Construction
Steam / Hot Water Pipelines
Power Plant & Cooling
Substation & Transmission
7
Start-up & Commissionning
8
Operation & Maintenance
Source | Authors.

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53
C h a p t e r 2
In addition, it is usually a complex task to secure necessary permits and licenses, especially for water 
rights and environmental permits. A complete Environmental Impact Assessment (EIA) is usually 
required for any major power project that also would need to deal with the drilling phase in the case of 
geothermal; preparing these documents often requires significant amounts of time and capital. 
Phase 1 is important to establish the rationale and to assess the need for the project in question and, 
at the same time, to justify investments needed for the exploration and test drillings (Phases 2 and 
3). Costs for this first phase are generally estimated at US$ 0.5 to 1 million. However, this estimate 
assumes that the basic information on the geology of the area under consideration is already available. 
In greenfield areas, this can increase to as much as US$ 5 million (Table 1.6). For these reasons, 
Phase 1 usually takes from several months up to one year to complete.