is commonly used for lighting in rural areas and in parts of cities which are not electrified.
Typical household consumption
As a rule of thumb, where 90 to 100% of lighting needs are met by kerosene, for low to middle income groups, consumption is roughly 1.8 to 3.6 GJ per household per year, or about 0.07 to 0.28 litres per night, with lighting periods of between two and four hours per night.
In six South Indian villages, electrified households used 1 kWh for lighting, whereas non-electrified households used 0.15 to 0.28 litres of kerosene, an energy ratio of 1:1.5 to 1:2.7.
In another Indian survey, the ratio for the bulk of rural and urban households was a bit lower at 0.13 to 0.15 litres per kWh giving energy ratios of 1:1.3 to 1:1.5 (Bio Energy Society of India, 1998).
Types of kerosene lamp
Kerosene is burned either in open wick lamps, typically with a naked flame from a wick protruding from a simple jar or bottle of fuel; enclosed wick lamps, in which the wick is surrounded by a glass chimney that creates an updraft past the wick and promotes a hotter, brighter flame; or pressurised lamps which normally use a coated mantle to provide an intense white light. Except for the pressurised lamps, most kerosene lamps provide very low lighting intensities, far below those required to meet reading needs adequately.
Kerosene wick lamps
For example, in a survey of low-income Indonesian households, it was found that the simplest, small wick bottle lamps, although they burn 10 millilitres of fuel hourly, gave out light equivalent to only a two-Watt electric torch bulb. For the poorest families, the costs involved are a major deterrent to adopting lighting technologies which improve on simple wick lamps. However, for families that own or are choosing between relatively advanced lighting equipment, initial costs are a small part of total life-cycle costs. Relative efficiencies and energy prices are therefore critical components in the economics of lighting. Here it is worth noting that in the Indonesian case just cited, it was found that commercial wick lamps were only two percent as efficient as incandescent lighting.
Kerosene pressurised lamps
For consumers, the economics of lighting methods depend on the trade-off between the high costs of efficient equipment and its lower running costs, and can best be compared by estimating payback periods, but taking the above factors into account.
Alternatives to kerosene lamps
Few kerosene lamps have an efficiency better than one tenth that of electric lighting. As a result, one frequently finds that the running costs of electric lighting are much less than lighting by kerosene for an equivalent light output. This point is of great importance for energy source substitution. Since electricity almost invariably replaces kerosene for lighting, and not vice versa, one might expect energy consumption to fall after the switch because of the much greater efficiency of electric lighting. However, most consumers increase their lighting standards (intensities) at the same time.
Although not yet widespread, use of solar photovoltaics
for lighting should be mentioned, as it can in some instances be a viable alternative to the more traditional lighting systems. Studies which have compared the economics of kerosene, diesel-electric and solar lighting in remote rural areas have found that solar and diesel costs are fairly close and generally lower than kerosene, assuming the same quantity of lighting for each method. Although this is likely to be the case in sunny regions where no electric grid exists and diesel fuel is expensive or hard to obtain, where these limitations do not exist, photovoltaic lighting is unlikely to be economic, at least at present costs. Furthermore, in the absence of subsidies or a well-structured financing mechanism, the high initial cost is bound to be an insurmountable barrier for most households.