Karachi: Pakistan’s geography is most conducive to exploitation of solar energy as it is 6th most fortunate country in the world in terms of solar irradiance and where sunshine availability is 8-10 hours per day over much of the plans of Sindh, Balochistan and Southern Punjab.
Solar energy intensity in sunbelt of Pakistan is approximately 1,800-2,200 Kwh per square meter per day which is most favourable for exploitation of solar energy. Potential capacity for installation of solar photovoltaic power by some estimates is 1,600 GW, which is 40 times greater than present consumption. Based on range of currently possible conversion efficiencies in area of one sq km has potential to produce 40-55MW power and can generate revenue conservatively estimated at Rs 1 billion per month at current average tariffs of Rs 10 per Kw-hr.
Since solar power is available only during times of sunshine, it can at most meet up to 30% of daily consumption without need for energy storage such as in underground salt deposits. Wasteland and desert of Thar, lower Sindh & Balochistan are prime contenders to establish large solar farms with capacities of generating more than 250 gigawatts electric power to meet energy shortfall over coming decades, says expert Samir Hoodbhoy who participated in technology breakthroughs in robotics systems, semi-conductors and first mobile cellular system developed. He directed creation of Central Design Bureau of Pakistan Steel Mills in 1988-92.
Hydrokinetic and solar thermal are two most promising alternate renewable energy solutions that can be used to reduce Pakistan’s rising $10 billion annual fuel imports and energy deficits and at same time preserve environment by not adding to hazards of increased carbon gases emissions caused by use of furnace oil and natural gas. Deserts of Tharparkar & Balochistan have potential for producing several hundreds of GWatts power.
If energy is stored in salt dunes, it would be available 24 hrs, 7 days throughout the year and eliminate need for expendable fuels. Water bodies including scores of points along Indus River, rapid flowing Kabul & Swat rivers, irrigation canals of Punjab & Sindh, and tidal currents of Arabian Sea hold much untapped potential for hydrokinetic power generation.
In most of glacier fed mountain streams of Pakistan, 16,000MW potential for generating electricity from fast moving streams is untapped due to difficulties of physical accessibility and to absence of a power grid network. However, local generation from smaller mini-hydel projects producing 50-500 kW through inexpensive generating units and serving small communities is increasingly being exploited in mountainous regions. In plains with slower moving river flow rates but with considerably greater volume of flow, potential is even greater, Hoodbhoy says.
A typical individual micro hydrokinetic turbine can generate from five to 25 kW of power. Clusters of these turbines can be combined to produce 50-500 kWatts. Their potential is greatest at fast flowing rivers and canals such as along Ghazi Barotha canal and Hub canal where stream velocity exceeds three meters per sec, and at foot discharge of existing hydroelectric barrages and dams. Sites such as along Kabul River & Swat River have a maximum flow rate of 4 to 5 m/s, with a minimum flow rate of 1.5 m/s.
Other than rivers, there are sites located along Jinnah, Chashma, Taunsa & Guddu barrages that have individual capacities of generating about 10MW electricity using hydrokinetic energy extraction methods. Power generated in many cases would be adequate for powering a riverside garrison town, a farming community or other population centers that are not connected to national power grid or those who suffer from incessant load shedding.
In south, tidal power projects may be used to power localities and small-scale industries located by sea. Some areas of high potential for application of hydrokinetic technology are entrance of Port Muhammad Bin Qasim can generate around 34MW of electricity through tidal energy. Other prominent sites where this technology can be installed are Gwadar, Pasni & Karachi coastal areas.
With a level of solar irradiance of 19 million joules per sq meter extended over more than 250,000 sq kms of plains and desert of Balochistan, potential for solar power exceeds 25,000 GWatts. Even if one percent of this land mass was apportioned for solar energy farming, this represents potential generation of 250 GWatts which is 12 times greater than present installed generating capacity of 20 GWatts in Pakistan. Estimates of availability of wind potential vary.
Alternate Energy Development Board AEDB says Nokundi in Chagai district is one of world’s most ideal wind corridors where wind speed is almost constantly 12.5% higher than average required for energy generation. Other parts of wind corridor includes a 300-kilometre-long area with wide open spaces from Dalbandin to Taftan, a town on border of Iran, Gharo to Keti Bandar in Thatta district of Sindh province which is 60 km long and 170 km deep corridor and estimated to have a power generation potential of 50,000MW. Similar is case of Lasbela district of Balochistan province, where wind energy at sustainable speed, good for power generation is available with little variation in seasons (five meters per second in winter and eight meters per second in summer).
Hoodbhoy says in Balochistan potential for wind generation is attractive, current unsettled political, socioeconomic conditions are disincentives for construction of large wind turbines and solar farms with capacities of 1MW. Under settled conditions, this region could easily become attractive carbon gas free energy producing center.
Mini wind farming projects (1-50 kWatts) along with small solar farms scattered over remote inaccessible areas presents attractive proposition that will help mitigate localized needs of electricity for lighting, communications, pumping water with tube wells for irrigation, domestic consumption. Larger wind power and solar power farms with individual production capacity of 0.5-500 MW developed along wind corridors and desert hinterland of Balochistan, respectively, have capacity to radically alter socioeconomic plight of Pakistan by resuscitating agricultural and industrial sectors.