Exploring the potential for energy conservation in French households through hybrid modeling

Although the building sector is recognized as having major potential for energy conservation and carbon dioxide emission mitigation, conventional bottom–up and top–down models are limited in their ability to capture the complex economic and technological dynamics of the sector. This paper introduces a hybrid framework developed to assess future household energy demand in France. Res-IRF, a bottom–up module of energy consumption for space heating, has several distinctive features: (i) a clear separation between energy efficiency, i.e. investment in energy efficient technologies, and sufficiency, i.e. changes in the utilization of energy consuming durables which allows the rebound effect to be assessed; (ii) the inclusion of barriers to energy efficiency in the form of intangible costs, consumer heterogeneity parameters and the learning-by-doing process; (iii) an endogenous determination of retrofitting which represents trade-offs between retrofit quantity and quality. Subsequently, Res-IRF is linked to the IMACLIM-R computable general equilibrium model. This exercise shows that, compared to a 37% reduction in final energy demand achievable in business as usual in existing dwellings in 2050, an additional reduction of 21% could be achieved if relevant barriers to efficiency and sufficiency were overcome.