Zahoor A. AbbasiMonday, July 25, 2011 - GOVT. of Sindh needs to be commended for its continuing efforts for Development of Thar Coal such as creating a Private/Public sector partnership with Engro, signing MOU’s with various investors and massively funding the experimental technology of underground Coal Gasification (UCG). However, serious technical, administrative and cost issues remain unclear which if left unaddressed may result in complications and delays in the implementation and success of the Thar Coal project. The purpose of this technical discussion is to highlight some of these issues and provide suggestions from a professional perspective with intent to assist and to inform.
Since all major project planning efforts are geared towards achieving specific goals, which in this case is presumably the Govt of Sindh’s declared intention to develop 10 blocks of Thar Coal for production of 20,000 MW of electricity by the year 2030.
Thar coalfield water scenario:
The flagship Sindh/Engro project in block II of Thar coalfield, hinges on the availability of 300 cusecs (cubic feet per second) water from the Indus River System for operation of the Coal Fired Power Plant. Based on this, cumulative water demand for the proposed 10 blocks of Thar coal is calculated to be 3000 cusecs.
There is a chronic water shortage in Sindh; in fact it is so for all of Pakistan, where is this water going to come from? Assuming that somehow this additional 3000 cusecs of water does become available, the question then is, how do we get it to the coalfield? Due to topographic constraints, conventional gravity driven channel flow of water to the coal project is not possible, costly upslope pumping would be required.
Thar project is located near Islamkot in Thar Desert, which is outside the Sukkur Barrage Command Zone; the nearest source of Indus water is Jumrao, Makhi and Farash distribution complexes, these are all branches of Nara Canal which itself draws water from Sukkur Barrage. Due to siltation of the Canals and degradation of the nearly 80 year old regulatory system, additional water carrying capacity of the entire Nara Canal command stands significantly impaired.
To meet agriculture demands these canals are forced to carry water beyond their design capacities and will not be able to carry an additional 3000 cusecs of water for Thar coal without a total overhaul and remodeling of their entire regulatory systems. This will be a massive undertaking costing Billions of Dollars and at least 20 years. Does the Govt of Sindh have these financial resources and the luxury to wait another 20 years for power generation from Thar Coal?
A recently completed study by GOS at a cost of Rs. 180 Million estimates providing a mere 100 cusecs of water, in the first phase, from Nara canal’s Farash weir off take complex at a staggering capital cost of Rupees 27 Billion (operational costs of pumping not included). Capital costs for second phase of providing additional 200 cusecs of water are not yet known, total capital costs for the entire 300 cusecs will likely exceed Rs.100 Billion roughly equivalent to US $1.2 Billion!
This is cost of water for Block II only, what about the rest of the Thar coalfield?
Salient Features of the 100 cusec (Phase 1) Thar Coal Water Carrier Project.
S.No. Description Length
1 Construction Stone pitching Re-aligned Nara
Canal RD 0 to 105 21 Miles
2 Construction CC lining of Makhi Farash Link
Canal from RD 105 to 305 40 Miles
3 Construction of 100 cusec capacity CC lined channel from
Farash regulator to Nabisar through Dhoro escape 42.8 Miles
4 Two Pressure pumping pipe l ines of 4ft Diameter,
each 50 cusec capacity (one for auxiliary support) 62 Miles
5 Major reservoir (Nabisar & Vajhiyar) 0.16 MAF
6 Intermediate Reservoir 4 Nos
7 Pumping Station 5 Nos
Estimated Capital Cost of phase 1 – Rupees 27 Billion (US $314 Million)
(Source: GOS Department of Coal and Energy)
Providing Indus River water, at these costs is beyond the Govt of Sindh’s resource capability. World Bank and other multi-lateral lenders will likely consider these projects as economically unfeasible (which they are); in that case, it will be back to square one for Thar Coal development, minus a lot of money and time.
Transporting a mere 300 cusecs (for block II only) at a Capital Cost of Rs. 100 Billion (US $1.2 Billion) will require water to be pumped upslope through six separate, 4 feet diameter pipe lines, each 62 miles long, with 5 reservoirs, and operating 5 large scale pumping stations in the middle of the desert with logistical problems such as equipment breakdowns, spare parts, diesel fuel availability, staff reliability and O & M funding shortages typically experienced by projects in Sindh.
Water supply from this source will be cumbersome, expensive and unreliable, with a very high potential for operational failure, the province of Sindh has a long history and experience with operationally failed or stalled mega projects (SCARP, DRIP, RBOD …….to name just a few).
Apparently bringing Indus River water into Thar Desert for use in the power plants is neither economically nor practically viable. However a perfectly viable, technically superior alternative is available at a fraction of the above costs! This would utilize the available underground water in Thar and/or recover excess moisture from the coal itself and use it for power plant operations. This is a proven concept being successfully practiced in many European coal mines and power production facilities.
Groundwater and Power Plant Selection:
Suitable “Closed Circle Cooling Cycle” Power Plants need to be selected, these type of plants re-circulate and reuse the same water and are considered ideal for arid environments where water is scarce. Such power plants are operating in other countries; In United States, the Environmental Protection Agency (EPA) will not issue operating permits for new Coal fired power plants unless these types of systems are used. Existing plants will also convert to water conservation systems.
Various Thar coal seams occur between 450 feet to 650 feet depth, there are 3 ground water aquifers of which the base aquifer contains significant amounts of water and is highly pressurized and the only viable option for open Pit Mining is by dewatering and depressurizing these groundwater aquifers.
A state of the art mathematical model, simulating Thar coal area ground water conditions was employed by Rheinbraun Engineering (RWE). This same modeling method has been used successfully in European open pit mines by RWE and predicts that 41 cubic feet/second (cusecs) water will have to be pumped, for each mine in Thar to make the mining operations safe and workable. Water requirements of an 1100 MW “Closed Circle Cooling Cycle” plant are calculated to be 2.0 cusecs (cubic feet/second), therefore, no additional water will need to be imported from the Indus river system, thus avoiding huge Capital outlays and Operational expenses.
Selection of a “Closed Circle Cooling Cycle” Power Plant will also eliminate the need for large volumes of waste water disposal (saving significant costs), as it will generate only 2% to 3% waste water compared with an Open Cooling Cycle Plant.
Water Production and Disposal:
Massive amounts groundwater will be pumped out in order to dewater and depressurize the aquifers to achieve safe mining conditions, with proper planning the mine operators and Govt of Sindh can realize additional windfall profits by recovering/harvesting the natural gas (Coalbed methane) that is always present in Coal, which will be automatically released due to depressurization of the coal seams. United States Geologic Survey (USGS) sources estimate that Thar Coal deposits contain over 21 Trillion cubic feet (TCF) of recoverable natural gas with a production potential of nearly 1 Billion Cubic feet/day.
Water produced from the pumping operations is as precious a natural resource as the coal itself, Thar water is considered to be “moderately saline” containing 7500 to 10,000 (PPM) parts per million total dissolved salts (TDS), compared to sea water which has 35,000 to 40,000 Parts Per Million.
This water can be treated and used for cultivation of high value crops such as fruits and vegetables. Water produced by each mine will be able to cultivate 15,000 acres. Using the Govt of Sindh’s planning benchmark of 10 Blocks (mines) by 2030, the groundwater thus cumulatively produced can cultivate up to 150,000 acres of high value crops and will provide the basis for developing livestock industry, which is well suited for Thar and its inhabitants.
Downstream economic benefits of this approach are immeasurable in terms of job growth, poverty alleviation, improved food security and food price stability due to increased production and transportation through the existing road network in Thar. Present mindset of entities dealing with Thar Coal is dispensed towards considering Thar groundwater as a waste water “effluent” that needs to be disposed off; costly plans for this (similar to the ill advised endeavor to import Indus River water) may already be in the works. This mindset needs to be changed; Thar Groundwater is a precious natural resource and definitely not “effluent” disposing it as such would be a monumental and a historic mistake which Sindh and its people will surely regret in the coming years of expected severe water shortages.
Ironically, on one hand policy decisions are formulated for undertaking the difficult task of importing a very expensive and unreliable supply of Indus River water for use in open cooling cycle plants, which in turn will effectively convert this same water into contaminated “effluent” which will then have to be disposed off in accordance with internationally acceptable environmental practices, at a huge additional cost.
Simply stated: “The Govt of Sindh will first spend trillions of rupees to help create a problem and subsequently spend other trillions to solve this problem”. On the other hand, a simple policy paradigm shift of utilizing the indigenous water resource and selecting a suitable power plant design would save the nation Trillions in costs and years in terms of time to generate power from Thar coal.
—Zahoor A. Abbasi