DEVASTATION OF WATER RESOURCES: Upper Karnali
By Dr. AB Thapa
There are only three mega hydropower projects in our country which might have installed capacity over 4000 MW. They are the Karnali Chisapani Storage Project, Kosi High Dam Project and the Upper Karnali Storage Dam project. Installed capacity of all other hydropower projects is far below 4000 MW range. Out of these three projects, the high head Upper Karnali Storage Project is the most attractive for the generation of cheap electricity. Unfortunately, our country might soon be dispossessed of this highly valuable project.
It now appears according to the news published in local newspapers that our Government is in the process of embarking on a plan in defiance of the opinion expressed in the World Bank financed study report to implement the 300 MW Upper Karnali Mini Project completely ruining the prospect to develop the 4,180 MW Upper Karnali Storage Project which undoubtedly is the best among all large hydropower projects identified so far in Nepal. The World Bank financed study report has clearly explained that the 4,180 MW Upper Karnali storage project and the 300 MW Upper Karnali mini project are mutually exclusive. It would be a terrible blow to our country’s aspiration to use our hydropower resource for the uplift of our country’s economy. Water Resources Ministry and the National Planning Commission should be sincerely concerned about it.
An Empty Rhetoric
Our grandiose national plans to develop our water resources to uplift the living condition of common Nepali would be nothing more than an empty rhetoric if our policy making institutions failed to intervene in time to save the 4180 MW Upper Karnali Storage Project which might be the best in the world for the generation of cheap peaking energy on a large scale. We should not hesitate to invite competent foreign experts for advice if we find ourselves not capable to make correct judgment on this very important matter.
Why Upper Karnali Superior To Karnali Chisapani?
The Upper Karnali Storage project and the Karnali Chisapani Storage project would be having waterways quite comparable in length ( about 2 km), but the Upper Karnali project would be operating at a head almost two times greater than that of the project at Chisapani. It makes the Upper Karnali project far more attractive for the export of cheap peaking power to India than the Karnali Chisapani project. Reasons for it are explained below.
Of all the site characteristics, head is the most important. Design guidelines, 1989 approved by the American Society of Civil Engineers ( a document used throughout the world for the design of hydropower) has given some simple reasoning that would help to explain why the Upper Karnali project operating at a head about two times greater by comparison with the Chisapani hydropower could be built at far less per unit installed capacity cost. "Very simply if one doubles the head the quantity of water needed to produce a certain amount of energy is halved, Thus, for like site energy development the conduit area and reservoir volume are halved and further large cost reductions occur for powerhouse and machinery costs. This fundamental consideration is at the root of the large cost reductions that occur at higher heads." Needless to mention that the lower investment cost means the generation cost of the electricity would also be less.
Less Investment
By comparison with the mammoth 10,800 MW Karnali Chisapani Project the firm head of the Upper Karnali Project would be almost two times greater. It can be derived based on Stage A Optimization Study Data of the World Bank financed Karnali Project Study report that per KW installed capacity construction cost of the Upper Karnali Storage Project could be only about 70% of such cost of the project at Chisapani.
The Karnali River
The Karnali river makes a big loop in its lower reach near a place called Asare. From here the river flows in the south-east direction for about 25 kilometers, after that the river makes a complete reversal in its direction. The river comes back to a point just two kilometers away from its earlier position near Asare. There is a drop of about 150 meters in Karnali river bed elevations between these two positions merely two kilometers away from one another. The project to utilize this bend for power generation was originally known as the Karnali Bend Project. Later on the name was changed to Upper Karnali Project.
Study Of The Upper Karnali Project
The Karnali basin is the first to arouse keen interest in Nepal's vast hydropower development study. There are several attractive sites for the generation of cheap hydroelectric energy in this basin. In early 1960s an agreement was signed between HMG of Nepal and the UNDP for providing assistance to conduct a survey of the Karnali river and its main tributaries culminating in a pre-investment report indicating hydroelectric potential of the river as well as the best sites for hydropower development. The final feasibility report and general basin development report were submitted in February, 1966.
In 1980s further studies of the two projects were carried out under the aegis of the World Bank. They are the feasibility study of the Karnali Dam Project (Chisapani) and the pre-feasibility study of the Upper Karnali Hydroelectric Project ( Karnali Bend Site). Unfortunately, the scope of the Upper Karnali Project study was deliberately made very narrow. The size of the project was scaled down to be suitable to meet the Nepal's internal power requirement completely disregarding its vast potential to generate exceptionally cheap peaking energy for export to India. Thus there are at present two Upper Karnali projects. They are the 300 MW Upper Karnali Project and the 4180 MW Upper Karnali Storage Project. These two projects are mutually exclusive. In other words, it would not be possible later on to build the 4180 MW mega Upper Karnali Project without sacrificing the small 300 MW Upper Karnali Project. Though the Upper Karnali storage project study was not laid in the terms of reference, the pre-feasibility study report has clearly warned the government about the serious consequences if the 300 MW Upper Karnali project is implemented. The relevant excerpt from the WORLD BANK supported Upper Karnali project study report is presented hereinafter.
The 4180 MW and 300 MW Upper Karnali projects are Mutually Exclusive
The World Bank supported pre-feasibility study has disapproved of the small 300 MW Upper Karnali project. The relevant excerpt from the World Bank supported study report is presented below.
“Even when assuming that the KR 1 A run-of-river project ( small 300 MW Upper Karnali project) is a sunk cost, it will be seen that a single large power plant (4180 MW) associated with the major storage project is less costly than the combined cost of smaller plant at the same location (3532 MW) and a second power plant at the foot of the storage dam ( 408 MW) discharging directly into the KR 1A run-of-river project head pond. Based on this assessment, it appears that the later development of the major hydro storage project at Site KR 1 ( mega Upper Karnali Project) would cause the KR 1A run-of-river project to be effectively discontinued. There may be limited opportunity for secondary energy generation during the periods of spillage”.
Demand for Peaking Power in India
At present India is experiencing an acute shortage of peaking energy. At the beginning of the Eight Plan, the total peaking shortage was 20% whereas the energy shortage was only 9% of the total power generation. The thermal and nuclear power stations are suitable to supply electricity to meet the base load demand of the system. It is not economic to use them to supply peaking energy. Gas turbines can be used to meet the peak load demand because of low specific investment costs and quick start up. However, the efficiency is limited due to the high exhaust gas temperature of the turbine.
India is making every effort to improve the hydrothermal mix for ensuring better system operating condition. However, the share of hydropower in the overall power generating capacity has steadily declined since the last few decades. The share of the hydropower in the overall power generating capacity was 50.6% in 1963. But few years before it has come down to only 25.66%.
(Dr. Thapa writes on water resources)
