Decentralized renewable energy systems are supplying the needs in rural areas of Africa
While a centralized grid electrification is the long-term goal, a decentralized system is the short-term answer
By Robert J. van der Plas and Willem M. Floor
The World Bank
Modern energy growth is not keeping pace with population. Currently, some 2 billion people worldwide lack access to electricity. In Africa, only 18 million more rural people have connected to electricity over the past 20 years, while the continent`s rural population increased by 118 million. Given prevailing trends, it is unlikely that people living in rural areas or poor urban neighborhoods will soon enjoy the benefits of electricity.
Recognizing that many traditional, grid electrification programs have failed, energy planners and donors have begun to advocate a decentralized, dispersed, renewable energy approach using photovoltaics or solar home systems (SHS). Although SHS have an important role to play, this single option cannot fill the wide gap between those who enjoy the advantages of electricity and those who do not. To bring the advantages of modern civilization to the darkest corners of the rural world requires a market-driven approach that can make a wide menu of energy products available at affordable cost.
While centralized grid electrification has an important long-term role to play, a decentralized approach may be more appropriate in the short- to medium-term given the current low electricity demands of widely dispersed people in rural areas. Determining what actions to take now requires asking the following questions:
-What are the energy demands of rural households, and what types of services respond best to these needs?
-What can be done to accelerate the access rate of rural households to electricity services?
The energy services demanded most by rural households are cooking, water and space heating. These are provided mainly by wood and agricultural residues, not by electricity or solar energy, which may not be the most appropriate available energy forms. In fact, the average monthly demand for rural grid electricity is about 30 kWh or less. With increasing income, households tend to switch to more modern cooking fuels, and electricity is at the far end of the spectrum of options.1 Demand for motive power is satisfied by traditional sources, such as animal power, micro-hydro or petroleum fuels. However, compared to the energy demand for cooking or heating, motive power is very small.
The next highest energy demand is for lighting. Most rural households use some combination of firewood, candles and kerosene. A household usually has a few candles that enable people to walk about and one kerosene wick lamp for task lighting, such as cooking, eating or sewing. The typical kerosene lantern is a small soldered tin with a wick or, at best, a hurricane lantern. Pressurized kerosene mantle lamps are used 3 to 4 hours per day, with a weekly consumption of about 1 liter. Light output ranges from 10 to 15 lumens per light point.
Flashlights that operate on expensive, low-quality, dry-cell batteries are also used, and kWh prices in excess of (US)$500 are not uncommon. In addition, most households have a small radio operated on dry-cell batteries. Total monthly charges for kerosene and dry-cell batteries may amount to (US)$10 to $15. Thus, the price of lighting is high, but the services are poor.
The frame of reference for most rural households is the wick lamp–not the grid as is commonly assumed by energy planners and donor officials. As a result, any effort to improve people`s quality of life should be measured in terms of both costs and benefits relative to the wick lamp. With this in mind, the menu of options proposed for commercialization in rural and poor urban areas begins to look quite different from what is currently pursued.
Figure 1 illustrates a typical distribution of demand for electricity services, with an emphasis on lighting in Sub-Saharan Africa. The top 1 to 2 percent (depicted as group “a”) of the population demands full electricity services; without access to the grid, this group is likely to have a small generator set, fueled either by kerosene, petrol, diesel or photovoltaics. The next 3 to 5 percent of the population (group “b”) demands lighting, a radio, television and video. This is the target group for commercializing 40- to 60-watt SHS. The next group represents about 15 percent of the population (group “c”). As a group they would like lighting, a radio and possibly a small black-and-white television set. People in this group most likely have a car battery that they take into town when it needs recharging. It is this group that has a need for 20- to 40-watt SHS and possibly 10- to 15-watt solar lanterns.
Options for poor households
The largest group in Figure 1 (group “d”) consists of some 80 percent of the rural population and uses candles, kerosene and sometimes a flashlight for lighting. They may also own a small radio operated on dry-cell batteries. It is unlikely that this group will be electrified by either grid or SHS over the next 20 years. The challenge, then, is to develop and market low-cost lamps and appliances that allow poor households to enjoy limited lighting and other electricity services at costs they can afford. Higher-quality lighting would enable them to read or study without strain, making education possible. Many people are willing and able to pay the price for options that are reliable and have a considerable lifetime of use.
Solar lanterns that provide several times more light than does a kerosene lamp and are available in kits or as components. However, these are expensive, costing about (US)$200 and can be quite heavy and awkward to handle. A small solar lamp costing no more than (US)$25-50, with a lifetime of some three years, would make a major difference in the lives of many in this target group.
Fluorescent, portable lights, similar to what people in industrialized countries use for camping, combined with NiCad batteries and a 2- to 3-watt solar panel would meet the criteria for widespread application in rural areas. Users would be able to leave the lamp indoors and place the panel and batteries outside in the sun. Although not commercially available at this time, such a kit could have heavy consumer demand. A small fluorescent light with a 100- to 200-lumen output would already double or quadruple the current lighting of this target group.
A small solar charger of 2 to 5 watts is another option. This, combined with rechargeable NiCad batteries, would allow households to replace their non-rechargeable dry-cell batteries. Because flashlights and radios are already in place, the rechargeable NiCad batteries can be used without adaptation. This, together with other similar low-cost options, could help meet the needs of rural households who cannot afford electricity, whether grid-based or SHS.
The authors are currently trying to interest manufacturers in developing and producing a low-cost solar lamp and have received a number of offers. These lamps, as well as solar battery chargers, will be tested under real-life conditions as to their reliability and performance, as well as to the market`s response.
The case of Kenya
In many ways, the ideas mentioned previously reflect what is already happening in Kenya. A 1993 World Bank study showed that more rural and urban households in Kenya enjoy electricity through SHS than from the grid. In 1993, at least 20,000 households used a SHS compared to 17,000 connected to the grid. Many households, uncertain whether grid electrification would ever reach their area have purchased solar home systems, despite the absence of projects or programs to promote the systems. People pay cash for systems that cost (US)$700. It is clear that only the wealthiest of the rural population can afford SHS and that the market segment is likely limited to a few percent of the total population.
Nevertheless, the SHS that were sold provided enough business for the private sector to build up an infrastructure in rural areas. As a result, outlets are now found in most major and even smaller towns in Kenya. Total installed capacity of solar installations in 1993 was estimated at more than 1 MW that mainly supply electricity to private households. Kenya`s government reduced the import tax on panels in 1986, which helped accelerate the market.
Kenya`s 1994 business directory lists more than 40 solar energy businesses, including some 10 major wholesalers and retailers. Discussions with two of the larger new companies revealed an annual solar equipment turnover in 1994 exceeding $1 million, which was at least as high as 1993 levels. Although there are no statistics of imports and sales of solar equipment, it is highly likely that at least an additional 5,000 households purchased a SHS since 1993, and possibly as much as 15,000. Thus, trends indicated by the World Bank in 1993 appear to have continued and are now recognized by the “Rural Electrification Program of the Kenya Power and Lighting Co.” The program`s master plan, to be ready by 1996, specifically includes solar and other decentralized options.
Solar energy is now a household word among rural residents, who generally appreciate SHS performance. Most of the large, early systems consisted of kits with 20- to 40-watt poly/single-crystalline modules enough to power a few lights and occasionally run a radio or television set. Even though Kenya slipped into a recession in the early 1990`s, people have become so convinced about the reliability and quality of SHS that market growth continues.
Nowadays, people buy smaller systems, 10 to 20 watts, than what they purchased a few years ago, which constrains the services delivered. To cut costs, people are also switching to amorphous systems2 and leaving out such essential components as charge controllers.
Underlying this cost-cutting is a policy environment sending mixed signals to rural consumers. In 1991, the high import duty on poly/single-crystalline panels was reinstated, which changed the composition of consumer`s demand toward smaller, cheaper and often unreliable systems. In addition, the government continues to subsidize grid connection and energy services while taxing solar systems at high rates.
Call for a market-oriented approach
Population growth in Kenya far exceeds the growth rate of urban and rural grid connections and of solar home systems combined. In 1996, urban growth is estimated at 240,000 persons (40,000 to 60,000 households) (Figure 2). New grid connections will be approximately 10,000 to 15,000 in urban areas and 4,000 to 8,000 in rural areas. If 4,000 to 8,000 new SHS are added, the total number of households that will benefit amounts to about 20,000 to 30,000. This compares to the incremental growth of homes of about 100,000 to 150,000. The growth of the potential market is significant, and if the public sector tries to keep up, it may result in too heavy a burden for scarce public financial resources.
The traditional grid electrification approach is unlikely to produce timely or cost-effective results. While solar home systems can help fill certain market niches, they cannot function as the sole answer to rural electrification. Given rural households` ability and willingness to pay for energy services combined with their low load demand, a private-sector solution is the answer. This translates into a wide array of very small, solar-powered equipment, ranging from a few watts to several tens of watts, that can significantly improve people`s lives. Given such a wide menu of options, customers can then decide for themselves what works best. END
1 Modern use of traditional fuels is the first step (either from wood to charcoal, and/or from traditional to improved stoves); the second step is changing from traditional to modern fuel such as kerosene or LPG.
2 Amorphous panels are cheaper to produce than poly/single crystalline ones, but require a larger surface to produce the same amount of power. In addition, power output degrades as much as 20 percent over the first three years of the lifetime, and total service life is much less than the 20-year expected lifetime for poly/single crystalline panels.
Editor`s note: This article reflects the views of the authors, and should not in any way be attributed to the World Bank.
Solar energy–The answer to rural power in Africa.
Robert J. van der Plas, Energy Planner, holds degrees in Applied Physics and in Development Studies from the University of Twente, The Netherlands. Since joining the Industry and Energy Department of the World Bank in 1985, Mr. van der Plas has been involved in new, renewable and traditional energy projects for the World Bank.
Willem M. Floor, Senior Energy Planner, holds a doctorate in Sociology from the University of Leiden, The Netherlands. Dr. Floor has been involved for the last 20 years in project development in the field of new, renewable and traditional energy projects. Since 1983 Dr. Floor has been working for the Industry and Energy Department of the World Bank.