AN ASSESSMENT OF THE GEOTHERMAL ... - Orkustofnun

Akbar 28 Report 5
FIGURE 20: Na-K-Ca temperatures vs.
Na-K temperatures plotted for the 17 samples
FIGURE 21: Prediction of saturation state
of calcite for selected water samples
6. DISCUSSION AND CONCLUSIONS
Power and energy are prerequisites for higher economic growth, poverty alleviation and social
development of a least developed country (LDC) such as Bangladesh. Per capita energy consumption
of Bangladesh is one of the lowest in the world. To date only 49% of its population has access to
electricity. Bangladesh’s present power generation capacity is about 6,727 MW. Currently, power
generation is highly dependent on natural gas, which accounts for 73% of the total electricity
generation installed capacity. But the existing gas reserves can only serve for another 10 years amidst
increasing demands for more gas. The present supply cannot fulfil the existing gas demand.
Indigenous coal has yet to make any significant impact on the energy scenario. Utilization of
renewable energy resources (solar, wind, biomass, hydro, geothermal, tidal wave etc.) has yet to reach
commercial dimensions and cannot serve as alternates to conventional energy resources. The recently
adopted renewable energy policy of Bangladesh has mandated the contribution of renewable energy
resources at 5% by 2015 and 10% by 2020 of the total power demand. Geothermal technology in
Bangladesh is quite new. No systematic work has been done so far to assess the geothermal prospects
of Bangladesh. The present study is an outcome of the current concern over renewable energy
exploration and an attempt to understand the technical know-how for assessing geothermal prospect
areas in order to exploit the potential geothermal energy.
Geothermal energy exploration involves initial cash investments, requiring good planning to minimize
risks and save money. It is necessary in the early stages to prioritize the areas to be investigated. The
average geothermal gradient along the southeast part of Bengal Foredeep region of Bangladesh varies
from 19.8 to 29.5°C/km and on the northwest stable shelf part of Bangladesh it varies from 20.8 to
48.7°C/km. In Bangladesh many deep abandoned wells initially drilled for oil and gas exploration
could provide valuable information about subsurface geology and the temperatures of areas of interest.
All previously explored areas were surveyed seismically along with other proven geophysical
methods. In the northwest stable shelf part of Bangladesh, the Singra-Kuchma-Bogra area of the
Bogra shelf requires considerable attention with its 4 deep wells with an average geothermal gradient
>30°C/km and in favourable geological conditions. A systematic study of these wells using the
available data (geology, geophysical logs, temperature/pressure, core/cuttings etc.) would provide
valuable information on the subsurface geothermal system. The Barapukuria coal mine area, the
Madhyapara hard rock mine area and the Thakurgaon thermal areas also lying in the northwest part of