It is heartening to note that the government is conscious of the prevalent high power tariffs, and has taken various measures recently in the direction of generating low cost electricity.
A major component of these policy measures is the development of additional hydroelectric power capacity on a fast track basis. Plans are underway to increase the contribution of hydel power generation from the current level of thirty percent in overall power generation to about fifty percent, within ten years.
The Power Policy 2002 proposes to develop medium and large hydroelectric power projects with cumulative capacity of at least 800 MW by the year 2010 and optimally 22,563 MW under different phases of plan implementation.
There is a need however that meanwhile, rather simultaneously, small capacity power plants be set up for which necessary infrastructure is already available.
These small units are categorised as mini (under 100 KW), micro (100 KW to one MW) and small (above one MW and upto 5 MW). Today, small hydel units offer emission free power stations for many remote communities throughout the world.
Amongst the developing nations, Nepal, India, China and Peru are operating a large number of small hydel plants. Even in the USA almost 80% of the renewable energy is being derived through small hydroelectric power plants.
At present, a number of small capacity hydel power plants are operating in the country, mainly in the Northern Areas, about 300 mini and micro units generating over 20 MW electricity in far-flung localities. For the last many decades, WAPDA is satisfactorily operating eight low-head small hydel power plants that include Dargai 20 MW, Jabban 19.6 MW, Rasul 22 MW, Chichoki Mallian 13 MW, Shadiwal 13 MW, Nandipur 14 MW, Kurram Garhi 4 MW, and Renala of one megawatt installed capacity. Nonetheless, the potential is not being utilised optimally, and a synchronised broad-based plan for the development of small-hydropower generation, at the national level, is lacking. An institutional mechanism, though, is available in the country, and WAPDA as well as the provincial governments plans many a scheme for quite sometime.
WAPDA has prepared various schemes for setting up of small power plants, and has standardised the electrical and mechanical equipment for these projects according to the availability of head and discharge at the sites. In May 2003, WAPDA had desired to undertake implementation of three low-head hydropower projects, in the initial phase, one in each province, with a cumulative capacity of over 14 MW.
These are Pakpattan Canal, Punjab-3.30MW, Machai Branch Canal, the NWFP-2.70 MW and Rohri Canal, Sindh-7.42 MW, for which feasibility studies were prepared by WAPDA. Expressions of interest were thus invited from domestic as well as international companies for the implementation of these projects. The response was overwhelming, primarily that of the local engineering companies, but no headway has been reported on these schemes so far.
The government of the NWFP has recently offered 32 hydropower potential sites to the private sector for implementation on BOOT (build, own, operate and transfer) basis. Punjab irrigation department is also working on the same lines, and the schemes are proposed on Indus, Sutlej, Ravi and Chenab rivers as well as on various canals in the province, to be implemented in collaboration with the private sector.
In the past too, almost ten years ago, the Punjab government had done similar exercises, allocating more than a dozen projects to the private sector, but none has seen the light of day. All these schemes can now be actively integrated into the urban and rural electrification programmes.
The potential for developing power generation at the national level, through establishing additional small hydel power plants, is estimated as 1,000 to 1,500 MW.
The proposed small units, in the range of 500 KVA to 5 MW - higher generation, can be obtained by installing multiple units and can be established in the NWFP, Northern Areas and Azad Jammu and Kashmir where high heads are available. A large number of sites have already been selected whereas feasibility studies on most of the projects are also available.
The hydropower generation potential, only in the Chitral region is estimated to be 600 MW. Similarly, Punjab can generate 425 MW electricity by installing small power units at its 23,712 mile-long canal system that includes 14 headworks and barrages, 21 major canals and 31 dams. Only the canals in Punjab with falls of more than 2-metre head can generate additional 65 MW.
These will be run-off river type projects, which do not require large storage reservoirs.
These units will cater to the needs of far-flung areas, without any requirement to be connected with the national grid. Again, the provinces/AJK and respective agencies in these areas are not required to follow the Power Policy 2002, strictly for small units, intending to serve locations not connected or not likely to be connected to the national grid. Establishing the small-scale hydroelectric power plants in the country will give various benefits.
A few are:
-- Electrification of remote areas and rural localities.
-- Lower capital investment and short lead time.
-- Simple civil works and minimum construction time.
-- Easy installation and minimum maintenance.
-- Low-cost power generation and transmission (as off-grid systems can be opted).
-- Increased energy efficiency for electricity transmission and distribution
-- Very low operating cost.
-- Power purchase price is estimated to be paisa fifteen per unit kWh.
-- Economic development as small and medium enterprises (SMEs) can be promoted in the region.
-- No environmental and health impacts.
Waterpower, or hydropower, is one of mankind's most ancient sources of energy, which cannot be depleted and is termed as recurring or renewable energy source. Hydroelectric power schemes make use of fall or head of water as it flows from behind a dam or down a steeply graded section of the river. The water passes through turbines, which then generates electricity.
There are various types of hydel or water turbines, depending on the effective head and water discharge, in use commercially these days. Impulse turbine is of the least complex design, and common for high head applications, but has the limitation of its size. Reaction turbine is highly efficient whereas its demerits are complexity and high cost.
Pelton wheel turbine is based on using the concept of jet force to create energy. The latest version of Pelton is known as Turgo, which can operate efficiently under low-flow conditions. These turbines last a long time and their maintenance is not expensive.
The advanced design of the system - fully computer-assisted modular design - offers standardised package. Standard turbines, Pelton and Francis, for head in the range of 2 to 800 meters, giving an output upto 2,000 KW are available. Turbines with automatic operation and able to convert low potential hydraulics to electricity have also been developed recently in the industrialised countries.
Another important feature of setting up small hydel power plants is the promotion of indigenous plant machinery and technical services. Local engineering industry may even be encouraged to form joint-ventures with foreign companies to develop such power projects. Local engineering industry, such as Heavy Mechanical Complex, HMC-3 and Heavy Electrical Complex in the public sector and about five industrial units in the private sector have the necessary engineering and physical facilities, whereas NESPAK has the design, consultancy and supervision services in the area. A comprehensive list of electrical and mechanical equipment and consumables produced by the local industry has been approved and notified by the government.
Major equipment for a small hydel power plant can be produced locally, almost 85% by weight and 60% by value. Once this technology is developed effectively in Pakistan, other local manufacturing companies shall assimilate it, like sugar plants, thus giving multiplier benefits to the national economy. Moreover, on commanding proper skills and technologies, plant and machinery for such a power plant can be exported to the underdeveloped countries. Also, gradual expansion, renovation and modification of existing small hydel power plants can be undertaken.
For an indigenously manufactured power plant, operating on indigenous and renewable fuel, the spin of activities ie manufacturing, construction, supply of other consumables, and operation of power plant shall directly help in the development of rural and remote areas.
The generation of job opportunities there shall also result in minimising the prevailing population migration to already heavily populated cities of Pakistan, resulting in socio-economic development.