Building Electricity Consumption Responds More Strongly to Population Change Than Climate Change
Projections of building electricity consumption are essential for many reasons, including electric grid operations, energy utility investment decisions, and global climate assessments. Multiple modeling approaches exist and differ in aspects such as spatiotemporal resolution and representations of building thermodynamics. Two structurally different models were used to study the relative impacts of future climate and population change on building electricity consumption in the western United States (U.S) and to explore the impacts of model structure on the results.
Developing a better understanding of the drivers of changes in electricity consumption is critical to planning an energy system capable of meeting future needs. Results showed that expansions of building floor space due to growing populations have a greater impact on building electricity consumption than climate change. This highlights the need for more research to understand how total floorspace and building stock characteristics, including the adoption rate of energy-efficient building technologies, are likely to change in the future as populations grow and migrate around the county.
Researchers used two models, Pacific Northwest National Laboratory’s Global Change Analysis Model (GCAM-USA) and Building ENergy Demand (BEND) model, to explore how building electricity consumption may change in four potential combinations of high/low population growth and climate change scenarios. Despite their structural differences, BEND and GCAM-USA project similar changes on an annual scale for western U.S. states and agree that population change is the dominant driver of future building electricity consumption. Climate change may increase electricity consumption by an additional 4-8%, with the largest changes occurring in the southern states of the western U.S., whereas population growth may increase electricity consumption by well over 100%. The two models have subtle distinctions in how they account for changes in the energy efficiency of the building stock over time. This is the primary cause of differences in their projections. The agreement between the two models lays the groundwork for future studies in which the BEND and GCAM-USA models could be used in combination to generate projections of building electricity consumption that are consistent across a wider range of spatial and temporal scales than those of any single model.