Small hydro-power units for remote villages

Published Aug 28, 2006 12:00am

THE government has committed to provide electricity to the entire population by 2007. Out of a total of around 130,000 villages, 99,600 were electrified at the end of March 2006. There are still 30,400 villages that have to be provided with electricity.

The hydro potential in Pakistan has been estimated at 46,000 MW; the present installed capacity is 6,459 MW. According to the ‘Policy for Power Generation Projects Year 2002’, Pakistan plans to commission 12 large scale hydro power plants, besides other relatively small scale projects.

Large hydro power generation projects involve a number of social, political and technical issues. Despite the government’s intensive campaign, it has failed to remove the fears of Sindh and NWFP on the issue of the Kalabagh Dam. Also, the construction of barrages and dams upstream on Indus has degraded the Indus delta.

The promises of cheap hydro energy from large dams, if analysed from a sustainable development prism, are not reliable because of two reasons; first, there is a vocal demand to include the social displacement and environmental degradation costs in the up-front capital costs of such projects.

Financing of such mega projects remains the most important aspect of this problem. Funding from international donors for such a project is difficult to receive, considering their commitment to facilitate investments in private thermal based power plants.

Second, even if the government arranges funding for such projects, the outlays involved in resettlement compensations are huge. For example, the government intends to spend Rs2.025 billion on the resettlement issues of the Kalabagh Dam by constructing 20 model and 27 extended villages.

Also the world over, a large hydro power is not considered as a renewable energy option due to its negative impact on the local environment and on the people displaced by water flooding. There is also strong evidence to show that such large schemes emit greenhouse gases, often equivalent to fossil fuel power plants, due to the decaying of biomass covered by the reservoir.

However, small hydropower plants have emerged as a desirable option, especially for hilly terrains where natural and manageable waterfalls are abundantly available. Being environmentally benign and having a small gestation period, small hydro resources receive worldwide attention both in developed and developing countries to augment energy generation. Small hydro plants offer a wide range of benefits, especially for rural areas in developing countries.

Development of small hydro power plants (SHP) around the world has increased substantially in the last 10 to 15 years because of limited and fast depleting fossil fuel resources such as coal, oil and natural gas.

The world’s installed capacity of small hydro plants is 47,000 MW, against an estimated potential of 180,000 MW. The development of small hydro projects appears strong in many parts of the world, especially in Asia, where it accounts for more than 19,000 MW of energy. Within Asia, China alone contributes more than 15,000 MW to the grid. There are over 420 small projects producing 1423 MW in India

Within the range of small hydro power plants mini-hydro typically refers to schemes below 1 MW, micro-hydro refers to schemes below 100 kW and pico-hydro to schemes below five kW. Although all of these technologies could be regarded as small hydro power plants, they have specific technical characteristics that warrant their own definition.

Generally speaking, micro- and pico-hydro technologies are used in developing countries to provide electricity to isolated communities where the electricity grid is not available, whereas mini-hydro tends to be grid connected. In most of the cases, no dam or reservoir storage is involved.

Generally the Northern areas are thinly populated. Low population and scattered settlements make it economically unfeasible to provide electricity supply to such places through the national grid.

These hilly areas receive a significant quantum of precipitation every year. Hence, water flowing through small rivers and streams is a potential source for small hydropower generation in order to solve the problem of energy shortages in such geographically discouraging areas

In fact, Pakistan Council of Renewable Energy Technologies (PCRET), a department of the Ministry of Science and Technology, has implemented 290 micro-hydro power (MHP) schemes in FATA and the northern areas with a total capacity of 3.5MW, ranging from 3-50kW per plant, with the participation of local community . All of these plants are run-of-river type in the low (four meter) to medium (30 meter) head range.

Similarly, Aga Khan Rural Support Programme (AKRSP) has constructed 171 micro-hydel units providing electricity to around 17,000 households in the remote and isolated region of northern Pakistan, and currently provides 11,000 households with electricity in very remote locations.

Once the plant is installed, the local community takes the responsibility of operating it. These plants provide electricity mainly for domestic purposes. Local people have installed agro processing plants for flour grinding, rice husking, lathe, in the power house. Such units are run during the day time, directly from the turbine shaft. The electricity produced through micro hydropower in the country is in the range of 5-50 kW.

Recently United Nations Development Programme (UNDP), the Alternative Pakistan Energy Development Board (AEBD) and German Technical Assistance Agency (GTZ) launched a Rs4.5 million project to promote adoption of renewable micro-hydro energy for the poor rural communities in Northern Areas.

A major advantage of micro hydro is that it can be built locally at a considerably less cost. For instance, imported turbine sets generating up to 50 kW cost approximately Rs30,000-60,000 per kW, while the local manufacturers located in Taxila, Gujranwala, Lahore, Karachi offer facilities for turbine manufacturing at Rs10,000-15,000 per kW, with marginally reduced turbine efficiencies. The cross flow turbine used by PCRET and AKRSP is manufactured in local workshops.

The unit cost of MHP in Pakistan is currently $1000-1200. The areas are remotely located at considerable distance from the national grid. Hence micro hydropower plants are the most attractive option of power generation. The system is a decentralised one, with no dependency on the national grid.

The substitution of conventional sources of energy like traditional biomass for cooking, diesel generators, kerosene lamps and biomass stoves with renewable energies like SHP help to decrease carbon dioxide emissions and also contribute to poverty alleviation and economic development by supplying the electricity needs for lighting, water pumping and operating small workshops.

These projects benefit the local environment by using a natural resource to generate much needed electricity without depleting the quantity or quality of that resource or harming aquatic fauna and flora.

The access to electricity provides women with an opportunity to improve their social and economic condition. Women in rural areas use time saved and extended working hours due to availability of light to manufacture traditional handicrafts for domestic and commercial purposes. Many children, especially young girls use the extra hours available during the nights to study.

Small hydropower (SHP) is a renewable energy source, a proven technology that can be connected to the main grid, used as a stand-alone option or combined with irrigation systems. The development of micro hydropower plants should continue, with continuous research for increasing the efficiency of these plants. Further, the government should launch new micro and Pico-hydro energy projects through Town council and Union council respectively. The costs of local manufacture can be reduced still further by developing local engineering capabilities and advisory services.

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