Monday, September 25, 2023

Coal bed methane holds huge future energy mix potential

Although Botswana’s Department of Geological Survey (DGS) has revealed a potential resource of 30 to 40 trillion cubic feet (TF3) of coal bed methane (CBM) gas trapped in coal seams at average depths of 200 meters, it can only be brought on stream if the country acquires extraction capability, Ministry of Minerals, Energy and Water Resources (MMEWR) Deputy Permanent Secretary (DPS) Nchidzi Mmolawa has said.
Officially opening the US-Botswana Unconventional Gas and Gas-to-Power Regional Workshop (UGW) held in Gaborone last week, on behalf of MMEWR Onkokame Kitso Mokaila who was held up in an emergency debate concerning the ongoing power blackouts, Mmolawa said CBM as an unconventional natural gas (UNG) apart from the lower costs and carboniferous emission rates, can readily substitute coal or more expensive diesel-powered thermal electric generators, once the market acquires sufficient reserves.
The CBM cost-saving aspects would amount to millions of US dollars given the ever escalating diesel or other combustible hydrocarbons pump prices.
Giving a comparative cost analysis between diesel and CBM Mmolawa explained: “The Government commissioned 90 MW peaking plant in Orapa, though a dual fuel Open Cycle Gas Turbines (OCGT) currently operating on diesel, can be converted to gas at a later stage, once the mining sector achieves commercial production. To this end, Government will during 2014 float an Expression of Interest (EoI) to supply gas to the Orapa plant to substitute the expensive diesel generation with CBM.”
The DPS said since CBM shares UNG chemical properties the hosting of workshops to exchange information with experts drawn from countries using it widely becomes paramount.
For instance, CBM exhibits uniqueness in geological settings mostly along coal seams with low permeability rocks, making its extraction more complex; requires more sophisticated drilling costing around US$2 million per shaft. Furthermore, the country’s CBM deposits if successfully tapped can immensely contribute to future energy mix.
Another bottleneck is that CBM is still at the exploration phase. The 2001 to 2003 DGS successful baseline CBM exploration project only stimulated private investment in prospecting from companies such as Kalahari Energy and Tlou Energy. Again, the years 2005 to 2010 witnessed an increase in the volume of CBM prospecting licences, as a response to the potential power generation market, due to the power deficit in the region.
Regional countries like South Africa and Mozambique have made discoveries of 400 TF3 and 120 TF3 of shale and natural gas, respectively. At the time of going to print, Namibia’s statistical data which is also involved in natural gas was not available.
Given the magnitude of exploration for natural gas within SADC, mining methods have to give optimum yields through environmentally friendly extraction.
“The imminent use of natural gas as a source of energy in Southern Africa entails the building of appropriate infrastructure and regulations in the utilization. In the same vein, Botswana as a mineral dependent country has defended as fait accompli denigrating foreign media on encroachments into game reserves. The Mines and Minerals Act calls for among others the compilation of a Natural Resource Accounts inventory giving a prudent evaluation of all those available which will inform future natural gas development plans, based on best international standard practices.
“We also plan to facilitate the downstream gas industry on completion of the upcoming Energy Policy, Botswana Energy and Water Regulator,” he said.
Mmolawa commended the US Embassy to Botswana for inviting experts to facilitate over pertinent issues drawn from US Departments of Energy, Geological Survey, Commerce, Interior and Colorado School of Mines; and covering travel expenses for representatives from 12 Southern African Power Pool (SAPP) member countries and Regional Regulators Association (RERA).


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