The ratio and quantity of residential electricity consumption in China are increasing steadily with the country's economic development; conservation of electricity consumption has special significance for reduction of carbon emissions. Based on data from 635 questionnaire surveys in four typical Chinese megacities (Beijing, Hangzhou, Guangzhou, and Guiyang), this study analysed the determinants of residential electricity consumption and electricity saving behaviours using the multivariate regression method, estimated the price elasticities of heterogeneous resident groups by combining the results of an elasticity formula and a multinomial logit model, and assessed residential electricity conservation potential. The results were as follows: economic indicators proved to be the factors most strongly influencing residential energy conservation behaviours; electricity elasticity varied significantly among heterogeneous demographic and income groups towards economic intervention instruments, within a scale of 0.16-0.63; and price interventions can effectively reduce residential electricity demand and reduce carbon emissions from electricity use by 3.2%-9.3%, thereby improving energy conservation. An appropriate policy mix should be adopted to reduce household carbon emissions effectively, including addressing regional disparities and expanding ladder price differences across different income groups to fulfil every resident's well-being, along with increased publicity and education efforts to improve people's energy-saving awareness in the long term.