Demand-supply reliability: A dry hydropower concept


    In solar and wind interventions, two things must be kept in mind before implementing it here in Nepal. Firstly, direct copy paste will not help here and secondly ground reality urges the need for a completely different approach in Nepal

    To ensure equal rights of every Nepali citizen over each and every drop of Nepali water, the nation must get the maximum possible revenue from every drop and that is only possible when Nepal adopts a hydropower model with a maximum water-energy conversion mechanism. Surprisingly, nobody asks whether that is happening in Nepal or not?

    The hydro power development model adopted so far is inefficient both in terms of cost and water-energy conversion efficiency. From the average of 60/62 operational HPPs, one can see the present trend of water-energy conversion of merely 0.18 kWh per 1000 liters of water use.

    This is mainly due to the flaws in the Electricity Act that talks about MW royalty but does not talk about royalty for water use on per liter basis. Except for the hydro power industry all other industries in Nepal have to spend a significant amount of money for their raw materials.

    Narrow and conventional perspectives always lead to a ‘zero sum game’ where gains of one must be accompanied by the losses of others. Almost all implemented, on-going and planned HPPs in Nepal are simply aimed for “resource colonization’’- favoring haves against have-nots. This dirty water politics under the influence of a few mighty people within and outside the Nepali border are simply trying to capture the rights over water resources thus making money out of this “free’’ and “clean’’ form of water fuel.

    This free water concept in the name of promoting hydro power development since 1992 has taken us nowhere, and it is in fact a planned hydro scam legally, and, unless it is rectified, there is no end to energy miseries in Nepal.

    So, instead of MW based royalty why not ask the developers how much water they annually intend to buy for a particular amount of energy (power) generation?

    At this juncture, it’s better to coin a new terminology “Water Handling Burden” in the Nepalese hydro power sector. It not only saves water use for the same amount of energy/power generation, but with reduced water handling burden one can imagine an intake pond of an HPP at the peak of a nearby hill to achieve more head.

    Except for nuclear power plants almost all reliable electricity generating plants are constructed near load centers and their raw materials (coal, gas, diesel etc.) are transported to them. Only hydro power plants are exceptional in this regard as they are located near its source of raw material, i.e. rivers.

    Just for a change, imagine an exceptionally high head water-energy conversion mechanism constructed such that its power house is located near an accessible area and its intake (pond) located at the peak of a hill nearby where a huge amount of rain water harvesting is possible, but with no major river close by. With ultra high head feature, this establishment will need significantly less water for the same amount of power (energy) generation.

    Less water handling burden will make its intake, waterways, powerhouse and downstream design quite small, simple and cheap. Only a longer section of waterways needs a little bit more attention. Requirement of less water also makes it more attractive as the deficit amount can be availed from nearby water sources.

    Suppose this rain water harvesting arrangement lies around 300m down from the picking pond like the arrangement of the conceptual high head water-energy conversion mechanism it provides a net head of around 1500 m in full discharge design. Then one can imagine transport of raw materials (i.e. water) to this arrangement which requires an uplift of about 300 m and then it gets discharge through a 1500 m net head. Does it make any sense?

    The world has recently started talking a lot about solar and wind energy harvesting. Both of these are intermittent in nature and in cloudy and no air-blow day they are even helpless.

    Integrating these highly unreliable generations directly to the grid requires a preparation of a huge backup generations to respond to the demand-supply variations as and when needed. Unfortunately INPS has very little such facilities so far.

    But for a change think what happens if we can make use of these intermittent sources of electricity to lift water up in our conceptual high head water-energy conversion mechanism (better term it a dry HPP)? With the said arrangement above, one unit of energy from such intermittent natural solar/wind sources can help generate 3-4 units of energy or more and that too as and when needed with unimaginable reliability.

    In solar and wind interventions, two things must be kept in mind before implementing it here in Nepal. Firstly, direct copy paste of the lessons learnt in other parts of the world will not help here and secondly ground reality urges the need for a completely different approach in Nepal.

    The steep gradient geographical feature of Nepal and abundantly available water resources (regular and rain water harvesting) gives hilly Nepal a chance where one can pump water up by X meters and can release the same through 2X – 10X meters or more. To store electricity, nature has availed Nepal with a fantastic natural gift of steep gradient feature; it’s just a matter of seeing it.

    PRAMOD RAJ POKHAREL , Pokharel is an energy expert

    Source : The Himalayan Times.