What emissions assign to electric power savings?

Based on fine-tuned modelling of the French electrical system, an increments method is offered for assigning CO2 emissions to energy savings. The French electrical system is indeed specific in that it has low average greenhouse effect gas emissions. However, it retains a significant share of emissions in overall terms, in the region of 25 Mt CO2. Such emissions come from old coal heat plants and new gas-based facilities. Detailed modelling of the system has been done in the ELFIN model. Introducing technical parameters of steam plants, such as their operating minimum, helped explain the emission breakdown over time. Such calculations introduce the possibility of assigning emissions avoided by energy savings by calculating their impact on future emissions, and not only by calculations linked to average and past emissions. The calculation dispersion does however remain high for very small increments. Conversely, major changes in the system, up to 20% savings in all - do not prevent from fining specific stable carbon values usable for the assessment of public policies or individual actions. (authors)