Characterization of Fugitive Methane Emissions from Commercial Buildings in California

Characterizing methane emissions from California's building sector

Gas System Decarbonization

ICF Incorporated, L.L.C.

Recipient

Fairfax, VA

Recipient Location

beenhere

$585,352

Amount Spent

closed

Completed

Project Status

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Project Result

During the first half of 2019, the team completed field measurements to characterize emissions associated with pipes and appliances in approximately 100 buildings. Building types include hotels, warehouses, offices, food services, and more. The research team analyzed its field data and used it as a basis for developing a statewide estimate of fugitive methane emissions from California's commercial buildings sector and completed a final report, which was reviewed by several colleagues from the Technical Advisory Committee, including CARB research staff. The final report was published in July 2020.

The Issue

Methane is a short-lived climate pollutant. Due to its relatively high climate impact in the short term, reducing methane emissions is an important strategy for reducing near-term warming. Previous research suggests the presence of fugitive methane emissions from natural gas-consuming buildings. However, the quantity and sources of emissions from commercial buildings has not been well characterized. The goal of this project is to better characterize fugitive methane emissions from specific appliances and system components downstream from the customer meter in commercial buildings in California, informing energy sector policy and planning, particularly related to natural gas systems.

Project Innovation

This project developed and validated methods for site recruitment, field testing, and estimating building-level and statewide methane emissions from commercial buildings in California. Analysis captured post-meter methane emissions data from natural gas appliances and pipe system components from a sample of buildings, then estimated total annual building-level and statewide emissions. The study estimated sectoral emissions using the two different approaches, including one that gives less weight to observed outliers. A small percentage of sources accounted for most emissions for both analyses. Because of factors such as a limited number of buildings and appliances analyzed and outliers in the sample, the uncertainty associated with this analysis is high, with a range of emissions spanning approximately 78.6 million to 1.1 billion cubic feet per year. Future studies can apply techniques developed in this project to a larger, more diverse sample of buildings to refine the statewide emissions estimates.

Project Benefits

California has initiated efforts to quantify fugitive methane emissions from various sources in the natural gas transmission and distribution system. However, emissions from commercial buildings have not been well characterized. This project is designed to provide an improved understanding of the sources and magnitude of fugitive methane emissions from commercial buildings in California. The results will benefit both the efforts of the California Air Resources Board to appropriately account for greenhouse gas emissions and efforts of CEC and partner agencies who are working on building decarbonization.

Consumer Appeal

Post-meter methane emissions comprise natural gas that has already been purchased, so commercial properties will benefit from purchasing less natural gas if these emissions are reduced. Based on ICF’s analysis, ratepayers in northern California would save up to $1.8 million per year in the aggregate, and ratepayers in southern California would save up to $3.2 million per year in the aggregate.