Trained in engineering and applied economics at Louvain, Antwerp and Stanford University, his present research covers electricity economics (cogeneration, planning, costing and pricing in power systems, distributed generation and grid access) and energy efficiency. He is co-founder of research and consultant units ‹STEM, CENERGIE and FINES›. He conceived, supervised and edited the State of the Environment Reports in Flanders (1993-98) and was the first president of the Environmental Advisory Council (1991-95) and principal advisor to the Minister of the Environment (1999-01). He contributes to the IPCC Third and Fourth Assessment Reports (WGIII: Mitigation and Adaptation).