Achieving −55% GHG emissions in 2030 in Wallonia, Belgium: Insights from the TIMES-Wal energy system model

Abstract

The Walloon Region has undertaken the ambitious engagement to reduce its greenhouse gases (GHG) emissions up to −55% in 2030. In this context, a regional model of the energy system is a useful tool to give insights to policy makers. We address the lack of an existing integrated tool by developing a technology-rich, bottom-up model for the region. The goal of this paper is twofold: we present the model and its functioning and then we analyse a cost-optimal way to reach the −55% regional target. Firstly, we describe the methodology, discussing how we build the sectors of our model and how the optimisation works. Secondly, we run the model with a constraint on GHG emissions to assess the impact of the mitigation target. We show that the total system cost of such an ambitious mitigation scenario is only ∼0.5% higher than the cost of an unconstrained reference scenario and that emissions reduction must start as soon as possible to stay on the cost-effective trajectory. Concerning technologies, windmills, photovoltaic (PV) panels and building renovations are cost-optimal solutions even with high discount rates.