Incentivising households to lower their electricity consumption is increasingly used as a tool to create a more flexible electricity demand. Previous reviews estimate that electricity savings of 6.4–7.4% can be achieved through monetary, informational and behavioural incentives. This papers argues that a more realistic estimate is of a 1.9–3.9% reduction in consumption based on the most recent experimental data, from both peer-reviewed and grey literature sources. Using data from 52 studies published during the “Smart Grid Era” (2005 onwards), the effects of incentives from 128 observations, amounting to 713,002 households, are analysed. The results show that individual and real-time feedback as well as personalised advice on how to save electricity are more effective than feedback on electricity costs and general electricity savings tips which lead to relative increases in consumption. Despite improvements in the quality of more recent studies, the analysis highlights the importance of methodological rigour in carrying out and reporting effects of incentives: an absence of a control group, of socio-demographic data, and the self-selection of participants into treatment leads to overestimation of effects.