Reducing future CO2 emissions — The role of nuclear energy

A study was made to analyze the potential of reducing CO₂ emissions and to identify important energy and technology options in future energy systems of Japan. The energy market optimum allocation model MARKAL was used for the analysis with a time horizon from 1990 to 2050.

The analytical procedures were as follows. First, a reference energy system was established by incorporating all important energy sources, energy carriers, and energy technologies that existed already or that might be introduced during the above time horizon. Second, future demand for energy services was estimated based on the two economic growth scenarios, high and low. Also, assumptions were made about the evolution of imported fuel prices, availability of energy resources, and so on. Third, under the above assumptions, the optimum energy and technology options were selected by minimizing a discounted system cost under different carbon tax schemes, and thereby the potential of reducing CO₂ emissions was analyzed.

The following results were obtained by the analysis. Without utilization of nuclear energy, the CO₂ emissions can be hardly stabilized at the 1990 emission level even in the case of the low economic growth and large scale deployment of CO₂ recovery and disposal assumed. A significant amount of fossil fuels will be used for power generation in order to meet the rapidly growing demand for electricity. Nuclear energy, by substituting fossil fuels for electric power generation, is expected to contribute to the reduction of CO₂ emissions. In addition, the average cost of reducing the emissions will be substantially lowered compared with a non nuclear scenario.