With the rapid advancement of urbanization in China and the sharp increase in natural resources consumption, it is crucial to quantitatively study the relationship between land resources utilization and energy consumption. This paper uses the panel data at the city level from 2004 to 2019 to analyze the impact of low-density expansion of land resources on power consumption and its internal mechanism. A significant U-shaped relationship exists between urban sprawl and power consumption, which passes a variety of robustness tests. Moreover, geographical indicators are selected as instrumental variables to deal with potential endogeneity. Heterogeneity analysis shows that there are differences in the impact of urban sprawl on electricity resources for different urban locations, population sizes, sprawl characteristics, and electricity consumption types. Further mechanism analysis shows that urban sprawl affects electricity consumption by affecting variables such as real estate investment and Internet development. The conclusions of this paper bridge the conflicting viewpoints of existing research and provide empirical evidence for the utilization of land resources and the formulation of electricity regulation policies in various regions of China.