Guillaume Wald won the prize for the best doctoral paper in energy economics awarded by the l’Association des Economistes de l’Energie (AEE) for his paper: :« The Effects of Energy Efficiency Obligation on Residential Energy use: Empirical Evidence from France ».

Guillaume Wald is a doctoral student at CERNA, le centre d’économie industrielle à Mines Paris – PSL where researchers focus on industrial economics and innovation, energy economics and environmental economics. "I'm working on the econometric analysis of policies to promote energy-efficient home renovation. I'm assessing their impact on household electricity and gas consumption", explains Guillaume Wald.

The doctoral student draws on the French Certificats d’Économies d’Énergie (CEE), scheme, the largest of its kind in Europe. CEEs oblige energy suppliers to finance energy efficiency work: 2.7 million sites were subsidized in this way in the residential sector between 2017 and 2019. This work represents an investment of around €4 billion a year. Guillaume Wald calculated the annual savings in residential energy consumption attributable to the scheme in each municipality. "We analyzed a new set of administrative data recording all the energy renovations supported by CEE. We compared the expected savings with the energy consumption of the residential sector in each of the 35,000 municipalities," he explains.

"In the best-case scenario, CEE-supported renovations reduce energy consumption in the residential sector by 0.85% each year. This is less than the European Commission's target of 1.5% per year for all sectors (except transport)". However, the residential sector alone accounts for 60% of CEE issued. It is therefore unlikely that the Commission's target has been reached.

How can such poor results be explained? Guillaume Wald comes back to the negative effect of bonus certificates. "The value of certain operations was increased to encourage energy suppliers to carry out specific work. However, bonuses are not the main problem with the scheme. In fact, the expected energy savings excluding the bonus - as defined by the standardized data sheets - are at least twice as high as the observed savings. We're talking about an energy performance gap of around 50% between forecast and actual, in line with estimates obtained from other evaluations in the USA, for example.

This work is a first step towards a better understanding of the impact of renovation assistance policies in the residential sector. Guillaume Wald's research program is much broader. "I want to analyze the interactions with other energy efficiency policies. I'm also interested in the effects of these policies on comfort and health, as well as on the creation of "green" jobs," he concludes.

Guillaume Wald is doing his thesis as part of the doctoral programme offered by The Transition Institute 1.5 (TTI.5), the first transdisciplinary research institute at Mines Paris - PSL. His thesis is part of TTI.5's first research theme, "The Design of Transition". Created in 2022, The Transition Institute 1.5 finances and supports theses, and disseminates research work related to the low-carbon transition. Find out more: The Transition Institute 1.5