Direct measurements of methane emissions from natural gas end use in Germany

Natural gas appliances and piping in buildings, or post-meter sources, are estimated to represent 15% of U.S. natural gas distribution sector emissions of methane. However, recent atmospheric methane measurement studies in urban areas indicate that end use emissions may be several times higher than currently estimated in national inventories. National inventories use bottom-up methods to estimate post-meter methane emissions, but due to the relatively small set of direct measurements, if available, many inventory estimates are likely to be highly uncertain. Moreover, there are systematic differences in building heating systems and natural gas appliance usage across countries and regions. For example, North American households mainly use forced air systems that rely on ducts and vents; while in Germany, it is common to distribute heat from a central heating unit through radiators. Therefore, although there have been several publications of direct measurement studies conducted in the U.S., it is difficult to extrapolate these findings to other countries and regions, including Germany, the largest natural gas user in Europe.

To better understand and quantify emissions from natural gas end use in Germany, we analyze spatially-integrated tall-tower eddy covariance surface fluxes of methane and conduct direct measurements of methane emissions from natural gas appliances and piping in homes and other buildings. The measurement data includes gas composition analysis and are analyzed in conjunction with natural gas appliances and building attributes. Our results can inform effective methane emission mitigation strategy development and energy transition policies in Germany and elsewhere.