SMALL HYDRO PROJECTS
Hydroelectric power is the generation of electric power from the movement of water. A hydroelectric facility requires a dependable flow of water and a reasonable height for water fall, called the head. In a typical installation, water is fed from a reservoir through a channel or piped into a turbine. The pressure of the flowing water on the turbine blades causes the shaft to rotate. The rotating shaft is connected to an electrical generator that converts the motion of the shaft into electrical energy.
Small hydro is the development of hydroelectric power on a scale serving a small community or industrial plant. The definition of a small hydro project varies, but a generating capacity of 1 to 20 megawatts (MW) is generally accepted, which aligns to the concept of distributed generation. The "small hydro" description may be stretched up to 50 MW.
Small hydro plants may be connected to conventional electrical distribution networks as a source of low-cost renewable energy. Alternatively, small hydro projects may be built in isolated areas where it would be uneconomic to distribute from a network, or in areas where there is no national electrical distribution network. Since small hydro projects usually have minimal reservoirs and civil construction work, they are seen as having relatively low environmental impact compared to large hydro. This decreased environmental impact depends heavily on the balance between stream flow and power production.
Plants with reservoirs, i.e. small storage and small pumped-storage hydropower plants, can contribute to distributed energy storage and decentralized peak and balancing electricity. Such plants can be built to integrate intermittent renewable energy sources at the regional level.
Potential of Small Hydro Power Stations in Pakistan
Pakistan at present is facing a serious and flagrant power crisis. A large section of the population in Pakistan’s rural areas is deprived completely of the energy supply, and even populations in urban localities have to face power cuts of roughly 8 to 10 hours per day. The situation is worse in remote areas, where the residents have to face the harmful consequences of load shedding for 12 to 18 hours per day. Pakistan, land of opportunities, is a profound blend of landscapes ranging from plains to deserts and forests to mountains, but for the last decade or so, the inhabitants of this sacred land are facing a very miserable situation due to excessive power shortage.
As a matter of fact, the energy deficiency has a direct impact on people’s standard of living and on the welfare of industry, and both of these are a good measure of a country’s economic development. It is not possible for Pakistan to provide electrical facilities to the entire rural population with its existing generative capacity, as the primary energy supplies are not enough to meet even the present demand. Moreover, many rural areas don’t have electrification facilities because they are either too remote or too expensive to connect to the national grid. So Pakistan, like other developing countries in the region, is adopting a Strategy of Distributed Generation for its remote and rural localities. Distributed Generation, also known as Community Based Generation, is a mechanism through which electricity is generated from any available renewable energy resource and distributed on the spot. The generated power is integrated with the national grid if possible. So, the most suitable renewable energy resources for distributed generation are small hydro power and wind and solar energy. Pakistan has great potential for all of these renewable energy resources.
Potential of Small Hydro Power
A hydro power station that generates electricity between 10 MW to 50 MW is known as a small hydro power station. Hydro power is available in Pakistan in the form of sea water, rivers and canals. This available hydro power can be used to generate electricity in different areas of the country. Due to prevailing acute power shortages and the government's inability to install and execute large hydro power plants, the attention is being focused on micro, mini and small hydro power generation in different localities of the country.
The small hydro power plants are cheaper in installation and maintenance. Distribution losses are greatly reduced due to decentralized and local management. The electricity it generates can be utilized in domestic as well as small and medium-sized industries. Small hydro power plants permit community participation in their initiation, operation and maintenance.
According to the prepared estimates of Pakistan’s Water and Power Development Authority (WAPDA), only Pakistan’s Khyber Pakhtunkhwa (KPK) province has a hydro power potential of up to 70,000 MW. The vast network of canals and hilly terrain in the KPK province provides thousands of sites for small hydro power stations. Depending on the head and flow of water, suitable turbines can be utilized to generate electricity from a few KW to MW from these sites. Secondly, small hydro power stations can be installed at natural, manageable waterfalls which number in the thousands in KPK and the Federally Administered Tribal Area (FATA). So a 50 KW micro power station can produce enough energy for hundreds of households. People residing in upper Dir, Chitral, Swat, Shangla and Mansehra have installed hundreds of such plants for their energy needs. Gilgit Baltistan has more hydro generation resources than anywhere in the country. The region has an area of 7200 square km and a population of nearly two million. It is a mountainous belt and the population is widely scattered. A large number of small hydro power stations capable of up to 18 MW have been established in the area.
Pakistan has a potential of approximately 100,000 MW for hydro power, whereas the exploitable potential for small hydro power is about 44,334 MW. The Alternative Energy Development Board is actively working with the Agha Khan Rural Support Program to install 103 small hydro power plants at Chitral and other places in Gilgit Baltistan. The provincial government of Punjab is also devoting full attention to the installation of a large number of small hydro power stations at different head works and other suitable locations by large canals. In addition, experts are ardently preparing feasibility reports on the subject. Similar work is also being done by the provincial governments of Sindh and Balochistan to establish small hydro power stations in their jurisdictions.
It is pertinent here to point out that the total installed electrical capacity in Pakistan is approximately 22,797 MW, with the contribution of hydro power at only 31%. The installed capacity of small hydro power is also very discouraging. Despite the huge potential for small hydro power, Pakistan has only 45 small hydro power stations with an installed capacity of 162.37 MW. Pakistan will have to address this significant issue by rooting out the prevailing problems of load shedding from its territories, as China, which has more than 46,000 small hydro power stations, has done.