The relationship between resource misallocation and productivity has become a hot topic in recent years, but few studies examined the impact of spatial misallocation of electric power resources (SMEPRs) on economic efficiency and carbon emissions. Here, we constructed a calculation model of SMEPRs that can measure both the misallocation degree and direction and uncovered the spatiotemporal evolvement mechanism of SMEPRs. On this basis, we explored the impact of SMEPRs on regional economic efficiency and carbon emissions using panel data from 29 provinces in China from 1988-2017. The results demonstrate that the high level of SMEPRs in China shows complex spatiotemporal characteristics and significantly affects the regional economic efficiency and carbon emissions. Specifically speaking: first, SMEPRs presents the characteristics of the coexistence of excessive and insufficient allocation among provinces and regions, the increasing extent of misallocation in the eastern and western regions, and the gradual decline in the central region; second, SMEPRs has a strong negative effect on the regional economic efficiency and carbon emissions by affecting regional industrial structures, which indicates that SMEPRs is an important factor restricting the high-quality development of regional economies. The research observations offer fresh insights to upgrading the high-quality and green development of China's power sector and promoting regional economic transformation and ecological sustainability.