Daily Times

The Council of Common Interests (CCI), Government of Pakistan, on Thursday, August 6, 2020, approved an alternative and renewable energy policy (2020) of the government. This policy will unleash the full renewable energy potential of Pakistan. Energy plays a pivotal role in socio-economic development by raising the standard of living. It is becoming gradually accepted that current energy systems and networks, encompassing everything from primary energy sources to final energy services, are becoming unsustainable. A reliable supply of energy is essential to maintain and improve human being’s living conditions. Development of conventional forms of energy for meeting the growing energy needs of society at a reasonable cost is the responsibility of the governments. The diversification of fuel sources is imperative to address these issues. The limited fossil resources and environmental problems associated with them have emphasised the need for new sustainable energy supply options that use renewable energies. Development and promotion of new non-conventional, alternate and renewable sources of energy such as solar, wind, geothermal and bio-energy, etc. are now getting sustained attention.

Solar energy is the most abundant permanent energy resource on earth. Earth receives about 100,000 TW of solar power at its surface–enough energy every hour to supply humanity’s energy needs for a year. Photovoltaic (PV) is an empowering technology that has shown that it can generate electricity for the human race for a wide range of applications, scales, climates and geographic locations. PV technology is proven and easy to use solar of energy to generate electricity. It is being used globally to supply power to remote communities, utility peak load shaving, cathodic protection in pipelines, remotely located oil fields and gas oil separation plants, telecommunication towers, highway telephones and billboard, off-grid cottage/s, resorts in desert areas, water pumping for community and irrigation, municipal park lighting, exterior home lighting and many other usages. Standard commercial solar PV panel can convert 12 to 18 per cent of the energy of sunlight into useable electricity; high-end models come in above 20 per cent efficiency. Increasing manufacturing capacity and decreasing costs have led to remarkable growth in the industry over the past ten years. Pakistan is estimated to possess a 2.9-TW solar energy potential. PV units have been installed in mosques and schools and used for solar lanterns, solar home light systems, street and garden lighting and telecommunications. The country has a large number of remote villages that do not have electricity supplies. Linking the rural areas to the national electricity grid would be very difficult because it would need a lot of time and budgetary investments. However, solar energy technologies might be the lower cost options in rural Pakistan’s villages, where population and load density are low. Pakistan covers 796,095 km2 of land between latitudes 24° and 36° north and longitudes 61° and 76° east. Every day, the country receives an average of about 19 MJ/m2 of solar energy. However, adequate information regarding the availability of global solar radiation and its components at a particular location is essential to predict the efficiency and performance of many solar thermal devices. For proper utilisation of PV technology for energy generation, thorough and accurate knowledge of global solar radiation variation is required. In Pakistan only five stations: Karachi, Lahore, Quetta, Multan and Peshawar record global solar radiation on a horizontal surface. Therefore, for other locations in Pakistan, one has to depend on the different empirical relationships suggested so far for estimation purposes, employing different climatological parameters. In central and southern Pakistan (between 24°N and 32°N) generation of electricity through solar–hydrogen hybrid-electric power plants directly with solar-induced updraft wind energy is highly feasible. Solar–hydrogen hybrid-electric power plants consist of a solar updraft tower power plant, also called “solar chimney.” This utilises a combination of solar air collector and central updraft tube to generate a solar energy-induced convective flow, which drives pressure-staged turbines to generate electricity and hydrogen. During solar-active periods, along with a direct generation of electricity, hydrogen can be produced by photoelectrolysis of river water and can be stored for use as a raw material for fertiliser production, petroleum refining, and as a future transport fuel. Although initially, such plants are somewhat more expensive than pollution-loaded oil/coal-fired power plants, the costs are expected to become comparable, with low recurrent expenditures. Thus, clean energy is output. The technology is simple, reliable and accessible to the less industrialised countries.

Wind energy is anticipated to play a significant role to meet future energy demand. Wind turbines, both large and small, produce electricity for utilities and homeowners and remote villages. Wind turbines grouped, are referred to as ‘‘wind farms.’’ Wind farms comprise the turbines themselves, plus roads for site access, buildings (if any) and the grid connection point. Large grid-connected wind farms can help to alleviate power shortages. In fact, over the last ten years, wind energy is the world’s fastest-growing energy source with an average annual growth rate of 31.1 per cent. The study of the geographical distribution of wind speeds, characteristic parameters of the wind, topography and local wind flow and measurement of the wind speed are very essential in wind resource assessment for successful application of wind turbines. Pakistan’s coastline is about 1046 km long, extending from Indian border in the east to the Iranian border in the west. According to Pakistan’s Alternative Energy Development Board, wind power offers a technical potential of 360 GW, and this is supported by figures from SWERA, which estimate a 349.3 GW potential. The Gharo–Keti bander—Hyderabad wind corridor in Sindh has exploitable electric power generation potential of 11, 000 MW at a capacity factor of 25 per cent. The wind turbine and generator technology have reached a matured stage. The developments and improvements of the power electronic devices added an extra pace in its overall growth. However, the high penetration of wind power to the electrical network needs further consideration of the existing grid infrastructures. Grid integration issues of wind farms are the most important challenge for the future growth of this technology, which must be handled carefully.

Pakistan is an agricultural country and has a total estimated biomass power (bio-energy) potential of 50,000 GW h/year. While proven benefits on social aspects and macrolevel are associated with local bioenergy production, the future supply of biomass energy depends on energy prices and technical progress, both driven by energy policy priorities. With efficient use of biomass in producing energy, Pakistan can meet a variety of energy needs, including generating electricity, heating homes, fueling vehicles and providing process heat for industrial facilities, but there is still a need for more serious and extensive research to promote the renewable energy technologies. The shift in the energy mix also requires much more investment in infrastructure, equipment and in R&. Geothermal energy is another alternative and renewable energy source which consists of the thermal energy stored in the Earth’s crust. Geothermal energy process can produce a constant 24h base-load power where other renewable energies are unable whereas solar energy can only be produced during daylight hours and is diminished with cloud cover and wind turbines are dependent on wind speed, which is inherently variable. There are many geothermal springs in some areas of the country having varying degree of temperature (including boiling water emanations) with significant flow-rate. In Pakistan, the geothermal springs have been identified in three areas the Himalayan collision zone, the Chaghi volcanic arc, and the Indus basin margin. In the Himalayan collision zone, hot water with temperatures above 90 °C is found on the surface. In the southernmost region of the foredeep, an abnormally high thermal gradient of 4.1 °C/100 m is encountered in the Giandari oil and gas well. Likewise, the neighbouring oil and gas wells at Sui and Mart have also recorded higher than normal geothermal gradients of about 3.0–3.49 °C/l00 m. Farther northward the well at Dhodak has a similar thermal gradient. In this region, thermal springs have been recorded at Uch, GarmAb at the foot of Mari Hills, ZindaPir, Taunsa and Bakkur. In the south-Kirthar geothermal zone, the oil and gas wells drilled at Lakhra show thermal gradients above normal (3.3 °C/100 m). Farther southward the oil and gas wells at Sari and Karachi revealed a geothermal gradient of about 3 °C/l00 m. In Karachi, two hot springs exist one at ManghoPir and one at Karsaz. The geological setting of the south-Kirthar geothermal zone is similar to that of the south-Sulaiman geothermal zone. The Kirthar zone also includes a depression containing a pile of sediments 6–10 km thick. The basement beneath the depression shows the prevalence of higher compression causing by the anticlockwise rotational component of the Indo-Pakistan continental plate. The region is seismically active and epicentres of shallow earthquakes ranging in magnitude from three to five on Richter scale have been recorded. Pakistan can meet a variety of energy needs, including generating electricity, providing power to the agricultural sector, heating homes, facilities and pools in winter and providing process heat for food storage and agro-industrial facilities in remote areas, which faces fuel shortage during winter. However, there is an urgent need to initiate projects for resource definition and development of accurate and reliable geothermal energy resource map of the country. Projects can be carried out in collaboration with different centres of excellence established in advanced countries for geothermal energy mapping, primarily to describe heat flow, temperature-at-depth, and geothermal resource potential. These projects should also cover technical, economic, environmental as well as social aspects along with the integrative considered. Such projects will not only create awareness but also progressively reduce the uncertainty associated with resource productivity. There is still a need for serious and extensive research to promote the renewable energy technologies, training and mutual work of geologists and engineers. The shift in the energy mix also requires much more investment in infrastructure, equipment and in R&D in case of geothermal energy resource development in Pakistan.

The writer is an Associate Professor at the Department of Chemical Engineering, COMSATS University, Lahore Campus