After obtaining the rights to develop the concession area, BEL conducted several studies & researches:
1996-1997, assisted by Geosystem SRL, Italy: exploration activities by performing 200 point resistivity MT and gravity surveys.
2004, assisted by Geosystem SRL, Italy, conducted a 3-D MT interpretation, showing ary resistive plug present at depth of 5 km below sea level and conductive zone overlay at sea level.
Gravity Map
2003, West Japan Engineering Consultants (WestJEC), Japan, conducted a feasibility study. By calculating the volumetric stored heat, WestJEC concludes that the prospective development area can sustain the power generation of 143 MW for at least 30 years.
2004, Layman Energy Associates, Inc (LEA), USA. LEA concluded that there are two resources areas with combine area of 16.3 km2 based on the results of geophysical surveys and drilling. These include the 9.5 km2 Mount Tapak and the 6.8 km2 Lesung-Sangayang areas. Energy reserves were also estimated based on analogy with other developed high temperature volcanic field, and the method was used to estimate a risk-adjusted, 25 year generating capacity up to 235 MW for the combined Tapak and Lesung-Sangayang resource areas.
2005, Geothermex, Inc., USA, indicates the minimum reserves estimate (90% probable) is 160 MW/30yrs, the Median estimate (50% probable) is 350 MW/30yrs, the Mean is 390 MW/30yrs, and the standard deviation of the Mean is 200 MW (GeothermEx, 2004).
2011, SKM Toshiba conducted Pre-feasibility study entire Bali province.