Depleting fossil reserves and cost factor are compelling enough to look for renewable energy resources' utilization.
By MUHAMMAD ASIM, University of Karachi
Jan 30 - Feb 05, 2006
Nowadays there are a lot of discussions going on among the techies as well as the layman on the topic of renewable energy.
But still a mass population is unaware of this terminology. What renewable energy is?
"Energy obtained from sources that are essentially inexhaustible, unlike the fossil fuels, of which there is a finite supply."
Renewable sources of energy include wood, waste, geothermal, wind, photovoltaic, and solar thermal energy.
Conventional energy generated from fossil fuel is what we use in our daily life. The furnace oil used in producing electricity, gasoline or natural gas for motor vehicles and coal for running railway engines are all fossil fuels which undergo the phenomenon of depletion. With the passage of time, there is a reduction in the natural reserves of these resources. The depletion of Sui gas fields is the current example of this. For the sake of the same, the concept of renewable energy arose. Renewable energy refers to energy generated from such resources which do not deplete at all, sources that are regenerative - for example sunlight, air and biomass.
Both conventional and renewable energy sources have limitations, with the former having more. Conventional energy sources give us pollution as a byproduct, but it can be made available all the time. Renewable energy sources do not pollute the environment, but there is a limitation for their intermittent availability. There is no sunlight at night!
Also they are free of any input fuel, and hence their ever rising costs. They also incur much less operation and maintenance costs and are supposed to have a longer lifetime.
The total energy consumption of Pakistan in the year 1999 was 50 million metric tons. Fossil fuel was the major source of energy used. Hydroelectric and Solid biomass were the only sources of renewable energy.
The survey of energy resources, conducted in 2001, reveals that Pakistan uses only 5 energy sources, namely coal, gas, hydro, nuclear, oil and wood, with nuclear and wood making the smallest of contributions. After the discovery of the large coalfields in the Thar desert, coal has joined gas, hydro and oil as major contributors of the energy needs.
According to the survey the major markets for gas in the year 2001 were power generation (32%), fertilizer plants (25%), households and commercial consumers (23%) and general industrial users (20%). Small quantities of CNG were consumed as a transport fuel. But when we see the current picture, CNG is a major fuel for motor vehicles. This change was due to the hike in petroleum prices during the recent months. A large proportion of cars now use CNG as fuel. We daily see long queues of cars at the petrol pumps, waiting for CNG refilling
Pakistan's reported level of technically exploitable hydro capability places it in the middle ranks of Asian countries in this respect. The major hydro plants in operation are: Tarbela (3478 MW), Mangla (1000 MW), Ghazi Barotha hydro station (1450 MW) and Chashma (184 MW). The planned development of hydro capacity includes several very large projects, including Kalabagh (2400 MW) and Basha (3360 MW), however, Kalabagh still remains a question mark.
Oil has been produced in what is now the republic of Pakistan from the early 1920's. A number of fields were discovered in the upper Indus basin in the 1930's and 1940's. Since around 1980 a large number of hydrocarbon discoveries have been made in the central and southern parts of the country. But these discoveries are not sufficient for the increasing oil demand and consumption. The country relies totally on oil imports. The country is facing a serious increase in oil products and according to a senior finance ministry officer the next year's crude oil import bill would amount to $5.5 billion. For the current year, the government had estimated around $3.5 billion oil imports in the budget 2004-05, which has now been revised upward to $4.66 billion because of higher international oil prices.
The Government of Pakistan is strongly emphasizing a wide use of the vast deposits of coal found in the desert of Thar. It is planning to provide incentives to independent power producers to set up production plants at the mine sites and to sell electricity to the national grid. It is also urging cement industries all over the country to use this coal. However, the coal, low quality lignite, is known to contain significant sulfur concentrations. Extensive use of this coal is, therefore, likely to substantially increase environmental degradation, particularly when used in cement plants situated near cities and towns. Any future use of the Thar coal demands schemes for removing pollutants, particularly sulfur, and reducing ash contents. There are several ways of doing this, one among them being the conversion of coal to Di-methyl ether (DME) or any other compound of higher energy content.
Pakistan, at present, is facing serious energy problems: 95 per cent of its electricity generation comes from hydropower, which becomes less productive during the driest, hottest months of the year and cannot keep pace with the sharp rise in energy demand.
Also, about 70 per cent of the population lives in the 50,000 villages dispersed across the country. Many of these villages are far from the main transmission lines of the national grid and because of their relatively small populations; it is usually not economically feasible to connect these villages to the grid. Therefore it is inevitable to have renewable energy being used in Pakistan.
The major sources of renewable energy are:
Solar energy has excellent potential in the areas of Pakistan that receive high levels of solar radiation throughout the year. Solar technologies use the sun's energy to provide heat, light, hot water, electricity, and even cooling, for homes, businesses, and industry.
Every day, for example, the country receives an average of about 19 mega joules per square meter of solar energy. Not only can solar systems meet basic needs of rural areas, but can also reduce the pressure on conventional energy sources in urban areas, leaving more of these valuable resources for other domestic and industrial needs.
Solar power improves the living conditions of people in areas that have no other sources of electricity. It also provides better health and environment conditions for women and children, in particular, who are suffering health implications of inhaling fumes from dung and other materials.
During last few years Pakistan has shown quite encouraging developments in photovoltaics. The National Institute of Silicon Technology (NIST) under the Ministry of Science and Technology has developed the know-how and technology to fabricate solar cells, modules, and systems. Both the private and public sectors are playing their roles in the popularization and up-grading of photovoltaic activities in the country. A number of companies are not only involved in trading photovoltaic products and appliances but also manufacturing different components of PV systems.
Solar energy is also being used for production of drinking water from highly saline underground water in large parts of Balochistan, Sindh and southern Punjab.
Two plants consisting of 240 stills each with a capacity to desalinate 6,000 gallons of seawater per day have been installed at Gwader. The experiment has been very successful and could bring a change in the life style of the local population in water scarce areas. A number of such schemes are under active consideration by local governments in Balochistan and Thar.
As a matter of fact, using solar energy is more expensive due to the cost of equipment used. This is almost 4 times higher than any other energy sources available. But the savings on fuel, less maintenance and longer life are the features which encourages us to think about it.
In the past l0 years, the global wind energy capacity has increased tenfold—from 3.5 gig watts (GW) in 1994 to almost 50 GW by the end of 2004. In the United States, the wind energy capacity tripled from 1600 megawatts (MW) in 1994 to more than 6700 MW by the end of 2004—enough to serve more than 1.6 million households. The projection for this figure is 8740 megawatts by the end of the year 2005.
Wind is another source that could be utilized for power generation as well as other applications in Pakistan. Average wind speed for some selected sites is not enough for wind power generation to be feasible, although the wind speed can still be utilized to run windmills to pump water for the areas where it is available at short depths up to 100 feet.
A wind turbine is used to generate electricity for the utility grid. The electricity is sent through transmission and distribution lines to homes, businesses, schools, and so on. It works the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts, are used for homes, telecommunications dishes, or water pumping.
About 30 wind mills for pumping water have been installed for experimental purposes in different parts of Sindh and Balochistan. The experiment suffered due to low quality mills and lack of proper infrastructure for maintenance. Recently a proposal for a wind survey is being launched to provide authenticated data on wind speeds at different altitudes along the coast and mountains. A wind-energy park is already functional in Rawalpindi, which lies just alongside Islamabad, and others are planned for Karachi as well.
Biomass is plant matter such as trees, grasses, agricultural crops or other biological material. It can be used as a solid fuel, or converted into liquid or gaseous forms, for the production of electric power, heat, chemicals, or fuels. By integrating a variety of biomass conversion processes, all of these products can be made in one facility, called a bio-refinery. A bio-refinery is a facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass.
Pakistan is a predominantly rural society where biomass fuel is the major source for cooking and heating. Women are primarily involved in biomass collection and combustion, therefore also inhale most of the poisonous chemicals present in the smoke. Biomass meets about 86% of total domestic energy requirements. 90% of the rural and 50% of the urban population depend on biomass fuels.
Biomass fuel is the major source of indoor air pollution and it is burned for cooking, heating and lighting homes. Biomass is the energy source of the poor in developing countries. Use of biomass leading to a high level of indoor air pollution, particulate matters and chemicals, is a serious potential health hazard.
Biomass is mostly burned in inefficient three-stone stoves leading to incomplete combustion and high levels of indoor air concentration of smoke. Indoor air pollution due to burning of biomass fuel is posing a serious threat, particularly to women and children in Pakistan. During peak hours of cooking the concentration of indoor air pollution may be many times higher than safe levels.
One of the available and practical options to improve the situation of indoor air includes development and adoption of fuel-efficient and smoke-free stoves for the population at large. This will have a 'double impact' of improving the environment and health, primarily of women and children and saving energy. Deficiencies have been identified in the implementation of such smaller-scale interventions, therefore, these could be addressed in future interventions. Development and dissemination of improved cooking stoves to improve kitchen hygiene and women's health on a large scale could have a major impact. Also research on efficient utilization of fuel wood should be strengthened and promoted.
The depleting world fossil fuel reserves, very high environmental pollution levels, and high import bills for fossil fuels are factors compelling enough to look for renewable energy resources utilization. Traditional sources of energy are often too expensive to satisfy their demand. More and more countries, therefore, are introducing economically and environmentally sound energy policies.
However, people are unlikely to adopt a completely new technology until they know something about it and have seen how it works. They need to have access to clearly presented information that explains the technical and economic benefits of replacing long-established traditional methods with new, innovative ways of doing things. This means that the new technology must be readily available.