PNNL

Abstract

Buildings account for approximately 36% of the United States’ total carbon emissions in recent years. Existing research found that building retrofit has great potential to reduce carbon emissions. Existing research adopted a constant electricity emission factor based on the past few years. However, electricity emission factors change over time due to the increase of renewable energy generation. To accurately predict emission reduction potential of building retrofit, this study adopts dynamically changing electricity emission factors predicted by National Renewable Energy Laboratory. Using medium office buildings as an example, we predicted emission reduction of eight building retrofit measures from 2020 to 2050 in five locations in the United States with distinct climates and renewable adoption rates. To evaluate emission reduction potential sensitivity to the compositions of electricity generation, five scenarios for renewable energy adoptions are investigated. The main findings are from three perspectives. (1) From measure perspective: two measures, improving heating and service water heater efficiency, can constantly reduce emission, but the reduction potential of other six measures changes over time. (2) From location perspective: a) the locations where there is little coal for electricity generation, the variation in emission reduction potential over time is trivial; and b) the trend of emission reduction potential variation is the same as the trend of coal usage variation. (3) From scenario perspective: building retrofit will lead to the most carbon emission reduction potential when the renewable energy is the least popular and least reduction potential when the renewable is the most popular.