Energy Efficiency has historically focused on delivering savings as a means to offset growth in energy supply. Today’s growing emphasis on decarbonization of the energy supply is driving renewables adoption and increased interest in electrification. As a result, energy efficiency is being assessed not just in its ability to offset load growth, but also for its ability to alleviate location-specific constraints on transmission and distribution infrastructure. This work demonstrates that advanced measurement and verification modeling techniques can be used to estimate the spatio-temporal impact of a portfolio of energy efficiency programs, relative to the distribution grid. It extends measurement-based methods to an entire Demand Side Management portfolio and uses a single model to predict annual as well as seasonal building energy use with near-zero bias. In addition, new metrics are introduced to assess grid level spatio-temporal impacts of energy efficiency. The advanced measurement and verification modeling technique was applied at three levels of customer account grouping: a proxy for the utility’s territory-wide distribution grid; the substation level; and the feeder level. The results show that the utility’s energy efficiency program portfolio delivers savings of over 12% at the proxy total level, with substation and feeder level savings ranging from 0.4%-26%, and -5%-42% respectively. These savings had a measurable impact of 1.0%-1.4% on the energy used at these locations in the grid. This work provides a methodological foundation that offers potential to connect efficiency with distribution planning, carrying implications for non-wires alternatives and targeted delivery of efficiency programs.