Event Description

Carbon emissions caused by electricity use in buildings are commonly accounted for using average emissions factors. However, decisions around building energy use should be based on marginal carbon impacts, and these are highly variable based on seasonal, daily and geographic factors. For example, in regions with sufficient (or excess) daytime solar generation, electricity use during these periods will result in low carbon emissions, whereas at other times demand may be met by fossil fuel plants, leading to significantly higher carbon impacts. This webinar will include researchers and industry experts who will discuss case studies, recent research and free online tools to help industry professionals and homeowners to understand how time-varying marginal emissions rates can inform system design and operational decisions to decrease carbon impacts.

The presentations will feature a case study in a Chicago building where a control intervention used real-time marginal emissions data to shift the electricity consumption to times when renewable energy would otherwise be wasted due to curtailment — when renewable energy is actively reduced to balance supply and demand. Presentations will also include a study that evaluated a load-shifting control strategy designed to align HVAC operation with low-carbon periods on the Northern California grid. Results demonstrated that this approach reduced emissions most effectively during spring when more renewable sources are available, while also showing the limits of load shifting as a single decarbonization strategy.

Speakers will also demonstrate use cases and features of two new online tools to help users understand marginal emission impacts. One tool enables comparison of numerous options for decarbonizing commercial buildings, including during HVAC retrofits. A second tool to be demonstrated provides household electricity customers with intuitive visualizations of marginal emissions based on Green Button electricity data. Time will be allotted for participant questions and discussion.

The objective of this course is that at the conclusion, participants will be able to:

1. Explain what the term marginal emissions means and how it differs from average emissions, and why carbon emissions vary based on seasonal, daily and geographic variations.
2. Cite at least one case study that used marginal emissions data to reduce annual carbon emissions.
3. Demonstrate familiarity with an online tool useful for decarbonizing commercial buildings, including during HVAC retrofits.
4. Demonstrate familiarity with an online tool for visualizing homeowner energy use from Green Button data.