published on 1 July 2007 in energy
Renewable energy in Nepal
The resources of diversity
Nepal is an extremely varied country, with a complex morphology. It contains different ecosystems in a relatively restricted area and it is this variability that constitutes one of the riches of the country, since the natural resources are extremely diversified and spread among the regions.
The possibility of producing renewable energy, and in particular hydraulic power, is one of the most important virtual riches of Nepal. Virtual because there still are very few plants that can exploit important clean power resources. It has been calculated that if the country developed its resources adequately, it would, in a short amount of time, become an important exporter of electric power for the entire South-East Asia area.
The enormous potentiality of exploiting the water courses for the production of hydroelectric power, the use of solar panels to convert the great quantity of sunlight that shines over the entire Himalayan belt, and the energy of the wind that blows over the northern areas of Nepal, could satisfy the demand for electrification of the country and could also turn out to be an inexhaustible and “clean” source of profits.
However, which are the most important power resources? What has been done till now to exploit them?
Notwithstanding this great abundance of resources, to date only 35% of the population receives a supply of electricity, a percentage that decreases remarkably when we consider its diffusion in the rural areas, where the amount drops to around 5%. In order to face this lack of electric power, the population uses non renewable sources of energy, that are expensive and dangerous for their health, such as oil lamps that produce a poor quality of light and in the long run are harmful for the human respiratory system or large quantities of wood, which has been the cause of a seemingly unrelenting deforestation process of the country.
Besides the environmental and health problems connected with the use of these resources, also from an economic point of view these behaviours have been shown to be unsustainable : since Nepal does not have its own reserves of fossil fuel, it has to import large quantities of kerosene from the neighbouring countries, thus increasing its energetic dependence and increasing the public debt.
An inexhaustible fuel
Nepal is a country with a great abundance of water, due to the presence of rivers and lakes, and due to the potential reserve of the glaciers and perennial snow. There are three principal rivers in the country, they flow directly from the Himalayan mountains to India where they join the Ganges, and are an enormous energy resource. River Kosi is in the eastern region of the country, one of its affluents, river Arun, has its source in the Tibetan plateau at an altitude of over five thousand metres; the Kali Gandaki and Karnali rivers instead flow in the central and in the western part of the country respectively, and among their affluents there are water courses that originate in the mountainous regions of the Annapurna Range and the Northern Himalayan area.
Since the sources of the various rivers are at altitudes that vary from five thousand to eight thousand metres, the mass of water moves at an extremely high speed before reaching the Gangetic plain, thus representing an enormous potential of energy to be exploited.
The present state of development
The potential of hydroelectric power of the country has been estimated to be around 83,000 MW, even though at present only 600 MW are exploited, through few large hydroelectric power stations.
There are a number of reasons for this energetic under-development and they range from technical causes, such as the risk of building large dams in a country that is characterized by landslides and monsoon floods, to social and economic causes such as the construction of hydro-electric power stations for the production of hundreds of megawatts subsequently abandoned due to the political instability of the regions.
In the last few years besides the above complications there is an additional geo-political one – India, the main supplier of fossil fuel and electric power to Nepal, is progressively buying large portions of its water courses, specially in the Kosi and Gandaki rivers, with a double intent. On one hand to maintain the Nepalese dependence on energy, without allowing the country to build plants along the long water courses, and on the other to obtain this energy itself, subsequently selling it to Nepal.
Therefore, gripped between the lack of economic resources on one hand and the difficult socio-political context on the other, Nepal, at present does not seem able to develop a project to exploit its hydroelectric resources on a large scale, which would guarantee the energy requirements of its population.
Starting from a small scale
During the course of the last twenty years a new concept of hydroelectric exploitation has been identified, that of mini and micro hydro-power, which thanks to numerous local and international projects is showing enormous potentiality in the production of electricity in the rural areas.
In fact, the micro hydropower plants have a series of characteristics that are preferable to larger sized ones, such as for example the relatively more economic characteristics of the design and lower maintenance costs, the facility of installation in decentralized areas that are not very easily accessible, and the limited impact on the environment.
The total number of plants that are operating amounts to about two thousand units, with a total capacity of over 13,000 KW of electric power. The use of water courses as a source of power is, after all, an ancient tradition in Nepal, as for centuries the local populations have used traditional water mills, known with the name of ghatta, to grind the wheat and to husk rice, besides turning the typical prayer wheels of the Tibetan Buddhist monks.
During the course of the past ten years even these traditional machines have been modified in many ways, and can now produce electric power and mechanical power that are sufficient to provide electricity to over thirty family-groups each.
The largest system for micro-exploiting water is by using peltric technologies : these are miniature versions of the large turbines used by the hydroelectric plants, they are easy to realize and their cost is limited. In practice, the peltric system consists of a pipeline where water is channelled, the water then flows to a small turbine where, through a system of belts, the mechanical movement is transformed into electric power (approximately 0.5 to 3 KW) with the help of a small generator placed above. The only necessary condition is the presence of a waterfall of thirty to fifty metres, in order to generate the thrust required to move the turbines. Since the system, due to its small size and light weight (approximately 35 kilogrammes), is easy to transport in the mountain regions that have numerous waterfalls, it has proved to be particularly effective in the development of rural areas of the country, providing the power required for domestic activities of ten families each.
In Nepal there are two other important natural resources, even though their utilization is still not greatly developed, the sun and the wind.
The sun, in fact, shines over the Himalayan regions all year round since also the monsoon season is characterized by long periods of light. It has thus been calculated that on average each day, an area of one square metre can produce up to 4.5 KW per hour, which would be a fair reserve of electricity considering the average consumption of a Nepalese family.
Also the wind, specially in the northern and western mountainous areas, is present in great amounts, so much so that the problem of using the wind, as we will see, is tied to its force and abundance.
Solar panels and lanterns
The principal local application of solar energy consists of photovoltaic solar panels. This technology allows the direct conversion of solar radiations, and generation of electricity without any polluting emissions, to satisfy the requirements of lighting and mechanical movement. The operating system is rather simple and does not require any particular maintenance care, as the system that collects and converts light into power is entirely formed by elements that do not move.
Solar energy can also be used as power for the pumps that convey drinking water from the mountains to the various villages, a vital instrument for the health of the rural communities which still today use fuel oil.
Another use of solar energy that is widespread in Nepal is the use of solar lanterns. These are portable lamps that are powered by the sun through small cells which have a daily autonomy of approximately 5 hours. These lanterns have penetrated deeply into the rural areas of the country because they are available at a generally low price and thanks to these, entire families which are not connected to the electricity network can avail themselves of a greater number of hours of light for their domestic activities, thus reducing the consumption of timber.
Lowering the costs
Till date no census has been made of the number of photovoltaic conversion plants in the country, even though estimates indicate a rather low development index. The main problem consists in the unfavourable ratio between installation costs and the benefits that are obtained, even though the situation is now changing due to a general drop in the price of the main component parts. A solar panel, which cost approximately 100 dollars per generated Watt up to only a few years ago, now costs about one tenth of the amount. This is possible because in the last years the solar panels have been produced and assembled in Nepal, which is also a sector of economic growth for the local population.
Therefore, for the families that are not reached by the electricity network, recourse to solar energy can be an increasingly economic and functional choice, specially when used together with other alternative power sources.
Winds and failures
In Nepal, Aeolian energy is another possible and infinite power resource, with a high productive potential, even with weak or moderate winds.
However in the country, the exploitation of Aeolian energy is still at an experimental level, due to a series of problems. Firstly there is practically a total absence of experimental data regarding the direction, intensity and frequency of the air currents in the Nepalese region. Due to a defect in technical competencies for the study and development of Aeolian energy the country has never invested seriously nor continually in the use of wind for power purposes.
For this reason even one of the principal experiments in this field, promoted by the Danish government, in collaboration with the Nepalese Energy Authorities, failed completely. The construction of the first plant for the production of Aeolian energy, with a capacity of 30 KW, in the Mustang regions, ended after only a few months, because the force of the wind damaged the entire structure irremediably.
Another limit of Aeolian energy consists in the costs of the realization of the plants that till date have been prohibitive. The basic technology is still too expensive, and especially the need to transfer the electricity produced at high altitudes, (in order to maximize the action of the wind) to the villages involves the creation of a transportation line that is expensive and often difficult to realize due to the morphology of the regions.
So, awaiting a decrease in the costs of the turbines, Aeolian energy in Nepal is exploited through the traditional applications that provide prevalently mechanical power and generate only small quantities of electric power.
Biogas is a low cost natural resource that brings immediate benefits, in economic terms and health. The idea, that is simple and functional, is to convert the biomasses formed by organic waste and animal and human excretion into methane gas, to be used directly for domestic use, for cooking and lighting the homes.
A model country
Today Nepal is in the vanguard in the production of biogas, and its development and penetration model has been taken as an example by a number of poor countries with rural economies. The campaign for the diffusion of biogas in Nepal started at the beginning of the Nineties, when the government organized a financing and subsidizing programme for families requesting the installation of devices for the production of biogas. Today there are over 140,000 installations present in the Nepalese houses, and the government project should reach 200,000 installations by 2009, thus contributing to a decrease in the consumption of perishable energy resources, with a remarkable increase in the quality of life of Nepalese women and children who, besides having to spend a number of hours daily collecting wood, are also the main victims of its fumes.
The biogas production technology and process are simple and can be described here rapidly. Biogas is the result of the digestion of raw organic material by bacteria that may be found in nature in large quantities in animal dung, particularly that of cows and buffaloes.
The gas that is released as a result of this reaction, can take place only in oxygen-free containers, contains approximately 70% of methane, while the remaining 30% consists of carbon dioxide. The methane is used for domestic purposes, by simply channelling it towards the cooking range, and its use contributes to keeping the level of pollution due to carbon dioxide low, which is one of the causes of the world’s environmental deterioration.
Biogas has moderate costs because it uses a simple and economically accessible technology, and is produced following five fundamental steps: the dung is initially channelled towards the latrines in a pit, where water is added. Here underground the bacteria start the digesting process in a tank that is covered by a dome, where the gaseous substance, which is lighter than the underlying mud compound, is blocked.
At this stage the two products follow different courses. While the gas is channelled towards the kitchen to feed the cooking range, through another channel, the mud reaches a trench where it deposits, and is regularly used by the farmers. This compound, in fact, is surprisingly fertile for the surrounding cultivations.
Since in the economy of rural families the use of livestock such as buffaloes, cows and goats is fundamental, the raw material is always available and at a low cost. This fact, together with the government subsidies for the development of biogas was fundamental for the diffusion of the plants, which do not need any particular maintenance in order to operate correctly.
Due to the commitment of the United Nations Development Program, furthermore, the biogas plants are rapidly reaching family units that are in the more inaccessible rural areas, with the exception of high altitude mountain communities, where, due to the excessively rigid temperatures, the chemical process does not take place.
However these communities have greater access to water courses that are compatible with the micro hydropower projects, and therefore they too can use electric cooking ranges and lighting systems that are ecologically sustainable.
Made in Nepal
Nepal is therefore a country with an abundance of clean and renewable energy resources, even though much remains to be done, specially in the more critical sectors.
During the course of the last decade, however, the production of renewable energy plants components has shown a constant growth, so much so that today many systems that are used are produced exclusively in Nepal. This fact not only remarkably decreases the costs of production and installation of the energy technologies, but it has also increased the level of awareness of the use of alternative energies, among the rural population and among the representatives of the political class.
The tangible result has been the birth of innumerable energy development projects in most parts of the country, financed by international donors, that testify the importance of alternative energies and the conservation of the natural resources.
In order to start off a project that is satisfactory on a national scale, however, the problem to be overcome is the one tied to the production of hydroelectric power, that involves the construction of dams and large power plants, or the capillary diffusion of micro hydropower. Only in this way, in fact, the natural potentiality of Nepal will not only guarantee the energy requirements for the country’s growth, but will also prove to be a clean source of eco-compatible profits.
Written by Filippo Tessari