Switzerland, including the canton of Geneva, aims to reduce its electricity consumption following its decision to phase out nuclear electricity production. To investigate whether national policies and a regional programme, both of which aim at improving electricity efficiency, may have had an effect, we disentangle the effects of changes in economic structure, overall economic activity and structure-corrected energy intensity (SCEI) on the electricity consumption in the canton of Geneva and in Switzerland on multiple aggregation levels. The primary sector being negligibly small, we define the economy as the secondary and tertiary sector. Our analysis shows that changes in electricity consumption in the Genevan and Swiss economy were mainly caused by changes in activity and SCEI, although structural changes were not negligible. Specifically, we have shown that correcting for structural change may significantly impact comparisons between regional SCEI trends. Our analysis shows that economy-wide electric energy efficiency improved both in Geneva and Switzerland. This is the case both for the time period 2000–2007 (first period, before implementation of the energy efficiency programme [EEP] éco21 in Geneva) and for the period 2008–2014 (second period, after implementation of the EEP, excluding 2015). In Switzerland, the average reductions in SCEI in the study periods were similar: 1.2% per year in the first period and 1.0% per year in the second period. The average reduction in SCEI in Geneva was faster in the second period (2.6% per year) than in the first period (1.5% per year). These findings suggest that national energy efficiency policies that have been in place since 2001 have been effective. A strong increase in SCEI by 4.6% occurred in Geneva in 2015, diminishing the gap between the Genevan and Swiss SCEI. We found that this increase was likely to be caused by weather effects. When including the year 2015, the average reduction in SCEI in the second period was 1.7% for Geneva and 1.1% for Switzerland. Moreover, we have shown that weather effects were more strongly correlated with SCEI than with absolute electricity consumption, highlighting the importance of correcting for structure and weather effects. Further, weather effects made it difficult to identify contributions from the EEP to the reduction of the Genevan SCEI. We found that the applicability IDA for tracing the effectiveness of EEPs needs to be critically assessed in view of data availability, confounding influences such as weather effects as well as the maturity and size of the EEP.