The future evolution of energy supply technologies strongly depends on (and affects) the
economic and environmental systems, due to the high dependency of this sector on the
availability and cost of fossil fuels, especially on the small regional scale. This paper
aims at presenting the modeling system and preliminary results of a research project
conducted on the scale of Luxembourg to assess the environmental impact of future energy
scenarios for the country, integrating outputs from partial and computable general
equilibrium models within hybrid Life Cycle Assessment (LCA) frameworks. The general
equilibrium model for Luxembourg, LUXGEM, is used to evaluate the economic impacts of
policy decisions and other economic shocks over the time horizon 2006−2030. A techno-economic (partial
equilibrium) model for Luxembourg, ETEM, is used instead to compute operation levels of
various technologies to meet the demand for energy services at the least cost along the
same timeline. The future energy demand and supply are made consistent by coupling ETEM
with LUXGEM so as to have the same macro-economic variables and energy shares driving both
models. The coupling results are then implemented within a set of Environmentally-Extended
Input-Output (EE-IO) models in historical time series to test the feasibility of the
integrated framework and then to assess the environmental impacts of the country.
Accordingly, a disaggregated energy sector was built with the different ETEM technologies
in the EE-IO to allow hybridization with Life Cycle Inventory (LCI) and enrich the process
detail. The results show that the environmental impact slightly decreased overall from
2006 to 2009. Most of the impacts come from some imported commodities (natural gas, used
to produce electricity, and metalliferous ores and metal scrap). The main energy
production technology is the combined-cycle gas turbine plant “Twinerg”, representing
almost 80% of the domestic electricity production in Luxembourg. In the hybrid EE-IO
model, this technology contributes to around 7% of the total impact of the country’s net
consumption. The causes of divergence between ETEM and LUXGEM are also thoroughly
investigated to outline possible strategies of modeling improvements for future assessment
of environmental impacts using EE-IO. Further analyses focus first on the completion of
the models’ coupling and its application to the defined scenarios. Once the coupling is
consistently accomplished, LUXGEM can compute the IO flows from 2010 to 2030, while the
LCI processes in the hybrid system are harmonized with ETEM to represent the future
domestic and imported energy technologies.