UC Berkeley

Household energy transitions in low and middle-income countries can play an important and often immediate role in improving human welfare in various dimensions. Residential use of kerosene, particularly as a lighting fuel in inefficient lamps, is one such energy use with the potential for significant improvements and benefits. I present measurements and analyses investigating characteristics of kerosene use, pollutant emissions from its use for household lighting and how distal drivers affecting price and access to electricity influence household consumption. Towards informing household air pollution assessment methodologies, a comparison of markers of complex pollutant mixtures is performed in the context of residential sources of combustion in Nepal.

Laboratory and field measurement showed that 7-9% of kerosene consumed by widely used simple wick lamps is converted to carbonaceous particulate matter that is nearly pure black carbon. Combined with estimates of bottom-up fuel consumption from survey-based estimates of user prevalence, these high emission factors increase previous black carbon emission estimates from kerosene by 20-fold, to 270 Gg/year (90% uncertainty bounds: 110, 590 Gg/year). Applying consumption and lighting device stock estimates from a recent UN assessment approximately doubles the central emissions estimate. Estimated global BC emissions from kerosene lighting sources are approximately one eighth of residential biomass BC emissions and one sixth of those from diesel. As a source, the net effect of pollutant emissions from kerosene lamps on climate would be positive (warming) given the relatively small cooling effect of co-emitted pollutants.

Indoor area measurements during operation of cooking and lighting appliances indicated that trends in polycyclic aromatic hydrocarbons and elemental carbon did not always reflect trends in standard markers of pollution, suggesting that their use as supplemental markers could provide added information. The most pronounced difference was observed from area concentrations during use of the sawdust stove, where total PAH concentrations were measured to be three times greater than from the second highest PAH source, the traditional biomass-burning chulo stove, but sawdust stove PM2.5 concentrations were three times lower than from the chulo. Kerosene stove measurements showed average retene concentrations to be ten times higher than from the highest biomass source, adding to existing skepticism over the use of retene as a source marker of softwood combustion.

From an analysis of residential kerosene use in India, lighting was found to account for over 60% of residential kerosene consumption. The electrified household population constituted an approximately equal share of kerosene demand as the non-electrified household population. Impacts resulting from kerosene lighting activities were also substantial, providing a potential opportunity to improve population welfare while also alleviating economic burdens associated with government subsidies. Reductions in ambient primary PM2.5 resulting from the abatement of kerosene as a lighting source were estimated to avert between 0.27-1.6 million years of life lost in 2030. Early PM2.5 control costs to replace kerosene with pico-solar lighting devices were estimated to yield a net savings of $3.5 billion in 2030, principally due to reductions in kerosene purchases. Kerosene demand for lighting was found to be highly price sensitive, so that in a scenario in which current subsidies are phased out by 2030, kerosene demand drops by 97% compared to the Baseline. The economic inefficiency implied results in an estimated deadweight loss from the kerosene subsidy of $950 million in 2005, with over three quarters attributed to its use as a secondary lighting source. The most effective measures for reducing kerosene burden would be those that address use as a secondary lighting fuel.