Health and environmental impacts of energy systems

The assessment of health and environmental impacts of energy production has undergone a major evolution in recent years, reflecting progress in the underlying scientific domains. This paper reviews these developments and draws conclusions. The paper begins with a discussion of the relation between purpose and scope of an assessment. The following sections describe the methodology, with particular attention to key issues such as dispersion modelling, epidemiology, discounting, and the valuation of mortality. In the light of this discussion the major fuel chain studies since 1990 are reviewed and compared, to lead up to the present authors' best estimate of the impacts and damage costs of the most important energy technologies. The generalisability of the results to other sites and variations in emissions is discussed. Expressed in monetary terms as cost per kWh, the impacts of electricity from fossil fuels are not negligible even for new power plants they are in the range of 10 to 100% of the market price of electricity, being about two to four times higher for coal than for gas. The damage costs of nuclear are much smaller, a few percent of the market price of electricity even at zero discount rate, assuming normal functioning in a stable mature society. Not surprisingly, the damage costs of renewable energies are, in most cases, very small. In view of the controversies surrounding far future impacts, we also present some comparisons of physical impacts, for example showing that the increase in radiation dose from an all-nuclear scenario would be small relative to natural background.