Impact of Residential Retrofits on Gas and Electricity Consumption in France

TL;DR

This study analyzes how residential retrofits in France affect household energy use, showing significant reductions in electricity and gas consumption, especially when replacing gas boilers with heat pumps, using smart meter data and a difference-in-differences approach.

Contribution

It provides empirical evidence on the energy savings from specific retrofit measures in French homes, including the impact of heat pump installations on emissions.

Findings

Insulation retrofits reduce electricity and gas consumption by up to 13% and 16%.

Replacing gas boilers with heat pumps cuts carbon emissions by 85%.

Retrofits targeting heating systems significantly decrease heating energy use.

Abstract

This study examines the impact of residential energy retrofits on household energy consumption in France using smart meter data from nearly 2,500 Hello Watt users, using a two-period difference-in-differences design. The dataset combines daily electricity and gas consumption collected through smart meters, hourly temperatures from M\'et\'eo France, and user-declared home and retrofit information. As a control, we use a group composed of homes of Hello Watt users that are similar to the treated homes, but did not undergo any renovations. The average treatment effect on the treated is estimated with the estimator of Sant'Anna & Zhao (2020). Estimates are reported by energy source (electricity vs. gas) and by retrofit type. The retrofit measures considered are limited to single interventions: wall insulation, attic insulation, floor insulation, installation of an air-to-air heat pump, or installation of an air-to-water heat pump. A comprehensive retrofit is defined separately as the simultaneous implementation of at least two of these measures. Our results show that insulation works cause a significant decrease in both electricity and gas consumption (3% to 13% and 5% to 16% respectively, depending on the retrofit type). We also estimate the reduction on the heating consumption only (7% to 27% for electrical heating and 7% to 19% for gas heating). We also study retrofits that consist in replacing a gas boiler with an air-to-water heat pump, resulting in a cut of 85% in carbon emissions.