Alternative energy sources for rural areas
A significant per cent of the rural population has no access to electricity.
People living in remote areas still depend on traditional biomass i.e. fuel wood, charcoal, animal dung etc, to meet their daily energy needs. The present extensive use of these sources of energy has led to depleted natural resources and degraded local environment.
Traditional stoves cause indoor concentrations of pollutants. Such exposures are linked to acute respiratory infections, chronic obstructive lung diseases, low birth weights, lung cancer and eye problems, found primarily, among women and children..
Similarly, kerosene-based household lamps are inefficient, expensive, and source of health and fire hazards. These lamps produce unhealthy fumes which in poorly ventilated homes pose serious health hazards such as respiratory and eye problems; and lighting using kerosene can be twice as expensive as and up to 19 times less efficient per lumen of output than fluorescent lights using electricity as the energy carrier.
The poor often pay higher unit costs for energy than do the rich due to high cost associated with kerosene and LPG. Kerosene stoves are also a major cause of fires. LPG is relatively cleaner and safer fuel, but is poorly distributed. Its high cost is also a problem for poor households because of the initial cost of deposit or outright purchases of gas cylinder and stove compared to a kerosene stove.
Access to modern energy enables development of productive economic sectors in rural areas. Energy services add to economic growth by reducing unit costs. Additionally, if connected to the national grid, people would benefit from subsidised tariff rates. In the absence of modern energy services, the workers, teachers, doctors and nurses are reluctant to live in rural areas.
In the recent years, technological developments in small hydropower, biomass utilisation, wind energy and solar photovoltaic systems have created new opportunities for rural development. The decentralised rural electrification (DRE) is a proven competitor for grid extension.
The new renewable energy (RE) is still in its initial stages of development, and has not made any notable contribution to national electric supply. The government has set a target to generate 2,700MW electricity through renewable by 2015.
Currently, photovoltaic (PV) technology is being used for stand-alone rural telephone exchanges, repeater stations, highway emergency telephones, cathodic protection, refrigeration system for vaccine and medicines in hospitals, etc. Solar energy can be used to warm and cool buildings, heat water for industrial and domestic purposes, distil water and dry the agriculture products etc.
In Balochistan, 77 per cent of the population lives in the rural areas. The population density is very thin. About 90 percent of villagers are yet to be electrified. These villages are separated by large distances with absolutely no approach roads. Transmission lines are very expensive and there is no chance of grid connection in the near future. These conditions favour development of solar energy for off grid electric supply. With rising fuel prices, most of the solar energy technologies are becoming economically viable.
Along the coastline and in number of North-West Frontier valleys Pakistan possesses about 50,000 MW of economically exploitable wind-power potential. The sea coast is about 1,120 kilometer long and has a rural population of about 10 million people. Most of small coastal villages do not have access to electricity, which could be supplied through the use of wind power, available all year round in these areas.
Unfortunately, at present there is almost no share of wind in the energy mix. However, about 30 wind mills for pumping water have been installed on experimental basis in different parts of Sindh and Balochistan. The experiment suffered due to low quality equipment and lack of proper infrastructure.
Research has identified Pasni and Jivani as the prospective sites for use of four kW and 20 kW wind machines while locations of Karachi and Ormara can utilise wind power throughout the year using four kW machines. Small wind unit do not need grid system and can be deployed locally in rural and remote areas for generating electricity and pumping water for irrigation purposes.
Small hydropower plants are an alternative that has emerged as a desired option, especially for hilly terrain where natural and manageable waterfalls are abundantly available. Within the range of small hydro power, mini-hydro refers to schemes below one MW, micro-hydro below 100 kW and pico-hydro below for five kW. Although these technologies could be regarded as small hydro power, they have specific technical characteristics that warrant their own definition. Generally speaking, micro- and pico-hydro technologies are used in developing countries to provide electricity to isolated communities where the electricity grid is not available, whereas mini-hydro tends to be grid connected. In most of the cases, no dam or reservoir storage is involved in pico-, micro and mini-hydro schemes.
In fact, PCRET has implemented 290 micro-hydro power (MHP) schemes in FATA and the northern areas with a total capacity of 3.5MW, ranging from 3-50kW per plant, with the participation of local community. All of these plants are run-of-river type in the low (four meter) to medium (30 meter) head range.
Similarly, Aga Khan Rural Support Programme (AKRSP) has constructed 171 micro- hydro units providing electricity to around 17,000 households in the remote and isolated region of northern areas, and currently provides 11,000 households with electricity at remote locations.
These plants not only provide electricity for light at night but are also used to run small industrial units such as flour mills for wheat and maize threshing, and cotton ginning during day time when electricity is not required for lighting. Once the plant is installed, the local community takes the operating responsibility.
A major advantage of micro hydro is that it can be built locally at a relatively low cost. For instance, imported turbine sets generating up to 50 kW cost nearly $500--1000 per kW, while the local manufacturers offer facilities for turbine manufacturing at $170--250 per kW, with marginally reduced turbine efficiencies. The cross flow turbine used by PCRET and AKRSP are manufactured in local workshops.
The costs of local manufacture can be reduced by developing local engineering capabilities and advisory services. Unfortunately, turbine used by PCRET and AKRSP is manufactured in local workshop having no design or quality control facilities. In order to accelerate the development and enhance the performance of small hydro power, it is imperative to benchmark the work of the SHP industry to identify and adapt the proven best practices of the world leaders in the industry. As the huge potential of hydro power remains as yet untapped, there is a great potential for benchmarking in the SHP industry.
Decentralised renewable energy systems can also help reduce energy distribution losses and result in system-wide and national efficiency gains. Mainstreaming of renewable energy and greater use of indigenous resources can help diversify the energy mix and reduce dependence on imported fossil fuels, thereby militating supply disruptions and price fluctuation risks. In addition, costs and risks relating to fuel stocking, transportation, and temporary substitute arrangements are also irrelevant for renewable energy systems, except for backup purposes.
High investment but low operating cost is a common characteristic in renewable and advanced energy systems. Because of this, most of these energy systems are not very cost-competitive with other conventional systems on the basis of the initial investment cost. However, as these systems have much lower operating cost compared to conventional systems, the overall cost of energy appears much more attractive on the basis of life-cycle analysis. Moreover, when, due to the non-polluting nature of their operation, environmental credit is given to these sources, many of them appear cost-competitive with conventional technologies.