Energy plays a significant role in our life, and it has perhaps the maximum impact on activities, such as agriculture transport and other services. It contributes the most to increase output as an input. Differences in per capita energy consumption among countries have been found to be even greater than differences in per capita GNP. The developing countries of Asia, Africa and Latin Africa, where 71 per cent of the global population resides, consume only about half as much commercial energy annually as the United States alone which surprisingly has only about 5.5 per cent of the world's population.
Electricity, which is one of the most reliable sources of energy, is an essential ingredient of economic development and is equally necessary for non-commercial uses. The setting up of new industries and expansion of the capacity of consumer goods industries had led to considerable increase in the consumption of electricity in many countries. Apart from the programmes of rural electrification, the demand for electricity for lift irrigation through strengthening pump sets has also increased.
The rapid rise in the consumption of energy worldwide has caused environmental degradation. Hydropower, if tapped well, can help reduce this problem to some extent because it is the only largest contributor of clean electricity (15.9 per cent), followed by wind power (5.9 per cent), solar photovoltaic (2.2 per cent) and geothermal and other energy sources (0.4 per cent).
Despite considerable achievements on the power front, there have not been permanent power strategies for the last several years in many countries. Actually, various factors affect the performance of the power sectors and these have been examined in depth by concerned organisations. Broadly speaking, power generation has not been increasing proportionately due to various problems.
The development of hydroelectric power on a large-scale depends on the availability of good sites which are those with high head (height of waterfall), large discharge (the rate at which the river flows), large storage capacity and proximity to load centres (where the power will be used). The first two criteria are interdependent variables, that is, a low head can be compensated for by a high head. However, there are economic limits in this regards.
It has been discovered from research that energy efficiency for hydroelectricity ranges from 83 per cent to 93 per cent compared to 65 per cent efficiency for coal fired electric plants and 60 per cent for nuclear powered electric facilities. A hydroelectric dam is cheaper to maintain and operate, and it has a longer life span than either a coal or nuclear facility. Possibly, the most important advantage for hydropower is that it is as perpetual as sunlight.
Despite the advantages, hydropower is not free of shortcomings. Large hydroelectric plants are expensive to build. Reservoir sedimentation is one of the major shortcomings of hydroelectric dams. In dry climate areas, erosion and sedimentation rates are so high that a dam may not last even two decades. Hydropower plants cause the destruction of the natural beauty provided by a free flowing stream because of the construction of the dams. The reservoir can alter the ecological balance both upstream and downstream. Paddle fish, salmon and other migrating species of fish are particularly affected.
A research has shown that more ecological damage is caused for each unit of energy produced by hydropower than by any other sources of energy. This statement can be made only if the ecological destruction that could result from a complete nuclear meltdown or the potential destruction from haphazard dumping of radioactive wastes is not considered. Although nature has bestowed on Nepal a great wealth in the form of hydropower to fulfill our energy requirements, only a small percentage of the estimated capacity has been exploited so far. In fact, the existence of abundant resource is by itself not enough for meeting the people's needs. What is essential is their efficient and adequate exploitation which is possible only though improved techniques.
Most of the electricity produced in Nepal is consumed in the central region. The majority of the people living in far-flung areas have not been able to bring electricity to their houses. In order to solve this problem, Nepal Government should take a robust stand as reflected in its white paper's motto "every house is a power house". During the past few decades, there has been a resurgence of interest in establishing waterpower plants in many countries due to the increase in the cost of other fuels together with the realisation that fossil fuel resources are rapidly decreasing. The government has also placed emphasis on the establishment of both large and small-scale hydro projects for meeting the growing demand of electricity.
The significance of hydropower stems from the fact that unlike other resources, water is inexhaustible. The greater the endeavors to tap this potential, the more the benefits will be. Therefore, adequate attention should be given to the maximum use of hydro-power resources to meet the increasing demand for energy. The development of hydropower is not possible through external assistance only. In this, regard, mobilisation of local means and resources is of immense importance. For this purpose, the private sector should be encouraged. Moreover, plans should be made in such a way that both national and international organisations will be attracted to invest in this sector.
(The author is a freelance writer.)