Global atmospheric ethane, propane and methane trends (2006–2016)

Methane, ethane and propane are among the most abundant hydrocarbons in the atmosphere. These compounds have many emission sources in common and are all primarily removed through OH oxidation. Their mixing ratios and long-term trends in the upper troposphere and stratosphere are rarely reported due to the paucity of measurements. In this study, we present long-term (2006–2016) global ethane, propane, and methane data from airborne observation in the Upper Troposphere - Lower Stratosphere (UTLS) region, combined with atmospheric model simulations for ethane at the same times and locations, to focus on global ethane trends. The model uses the Copernicus emission inventory CAMS-GLOB and distinguishes 12 ethane emission sectors (natural and anthropogenic): BIO (biogenic emission), BIB (biomass burning), AWB (agricultural waste burning), ENE (power generation), FEF (fugitives), IND (industrial processes), RES (residential energy use), SHP (ships), SLV (solvents), SWD (solid waste and waste water), TNR (off-road transportation), and TRO (road transportation). The results from the model simulations were compared with observational data and further optimized. The Northern Hemispheric (NH) upper tropospheric and stratospheric ethane trends were 0.33 ± 0.27 %/yr and −3.6 ± 0.3 %/yr, respectively, in 2006–2016. The global ethane emission for this decade was estimated to be 19.28 Tg/yr. Trends of methane and propane, and of the 12 model sectors provided more insights on the variation of ethane trends. FEF, RES, TRO, SWD and BIB are the top five contributing sectors to the observed ethane trends. An ethane plume for NH upper troposphere and stratosphere in 2010–2011 was identified to be due to fossil fuel related emissions, likely from oil and gas exploitation. The discrepancy between model results and observations suggests that the current ethane emission inventories must be improved and higher temporal-spatial resolution data of ethane are needed. This dataset is of value to future global ethane budget estimates and the optimization of current ethane inventories. The data are public accessible at https://doi.org/10.5281/zenodo.5112059 (Li et al., 2021b).

Self-reported energy use in UK homes during the first COVID-19 lockdown: A survey study

To contain the spread of COVID-19, governments across the world imposed partial or complete lockdowns. National energy demand decreased in periods of lockdowns; however, as people spent more time at home, residential energy use likely increased. This paper reports results of a survey study with N = 1016 participants in the UK about their energy use practices during the first lockdown in March 2020. Results indicated that self-reported heating behaviours did not substantially change during lockdown. Regarding appliance use, in particular the duration of usage for TVs and computing equipment has increased and has spread out more over the day. Being less able to manage financially was correlated with greater usage of the smart-meter in-home-display and greater attempt to save energy was positively correlated with greater usage of the in-home display though correlations were small. In summary, the results indicate that home energy use behaviours, in particular around heating, did not change as much as might have been expected, which might at least partly be explained by the comparatively warm weather during the first lockdown. Corroborating the survey findings with actual energy data is the next essential step to understand findings in more detail.

Energy Model Development and Heating Energy Investigation of the Nested Thermal Envelope Design (NTED (tm))

Space heating accounts for approximately 60% of residential energy use in Canada. Minimizing envelope heat losses is one approach to reducing this percentage. Preliminary research investigated the energy-saving potential of an innovative design, referred to as Nested Thermal Envelope Design (NTED(TM)). The concept involves one insulated building inside another with dual thermal zones. Conservative modeling results from this work showed heating energy reductions of 74%. This research developed a new NTED(TM) simulation model to provide increased accuracy and gain a more complete understanding of the potential heating energy savings. The working performance was also investigated by modeling occupied-building operation. The resulting model has shown that the NTED(TM) design yields savings of 85% relative to a benchmark R-2000 building. These results improve on the preliminary values and reinforce the merit of the design as a means of achieving significant reductions in residential energy use.

Energy Model Development and Heating Energy Investigation of the Nested Thermal Envelope Design (NTED (tm))

Space heating accounts for approximately 60% of residential energy use in Canada. Minimizing envelope heat losses is one approach to reducing this percentage. Preliminary research investigated the energy-saving potential of an innovative design, referred to as Nested Thermal Envelope Design (NTED(TM)). The concept involves one insulated building inside another with dual thermal zones. Conservative modeling results from this work showed heating energy reductions of 74%. This research developed a new NTED(TM) simulation model to provide increased accuracy and gain a more complete understanding of the potential heating energy savings. The working performance was also investigated by modeling occupied-building operation. The resulting model has shown that the NTED(TM) design yields savings of 85% relative to a benchmark R-2000 building. These results improve on the preliminary values and reinforce the merit of the design as a means of achieving significant reductions in residential energy use.

Evaluating the Impact of the COVID-19 Pandemic on Residential Energy Use in Los Angeles

The 2020 COVID-19 pandemic provided an opportunity to assess energy use during times of emergency that disrupt daily and seasonal patterns. The authors present findings from a regional evaluation in the city of Los Angeles (California, USA) with broad application to other areas and demonstrate an approach for isolating and analyzing residential loads from community-level electric utility feeder data. The study addresses effects on residential energy use and the implications for future energy use models, energy planning, and device energy standards and utility program development. In this study we review changes in residential energy use during the progression of the COVID-19 pandemic from four residential communities across Los Angeles covering approximately 6603 households within two microclimate sub regional areas (Los Angeles Basin and San Fernando Valley). Analyses address both absolute and seasonal temperature-corrected energy use changes while assessing estimated changes on energy usage from both temperature-sensitive loads (e.g., air conditioning and electric heating) and non-temperature-sensitive loads (e.g., consumer electronics and major appliance use). An average 5.1% increase in total residential energy use was observed for non-temperature sensitive loads during the pandemic period compared to a 2018–2019 baseline. During mid-spring when shelter in place activity was highest a peak monthly energy use of 20.9% increase was seen compared to a 2018–2019 composite baseline. Considering an average of the top five warmest summer days, a 9.5% increase in energy use was observed for events during summer 2020 compared to summer 2018 (a year with similar magnitude summer high heat events). Based on these results, a potential trend is identified for increased residential load during pandemics and other shelter-in-place disruptions, net of any temperature-sensitive load shifts with greater impacts expected for lower-income communities.

Residential solid fuel emissions contribute significantly to air pollution and associated health impacts in China

Residential contribution to air pollution–associated health impacts is critical, but inadequately addressed because of data gaps. Here, we fully model the effects of residential energy use on emissions, outdoor and indoor PM2.5 concentrations, exposure, and premature deaths using updated energy data. We show that the residential sector contributed only 7.5% of total energy consumption but contributed 27% of primary PM2.5 emissions; 23 and 71% of the outdoor and indoor PM2.5 concentrations, respectively; 68% of PM2.5 exposure; and 67% of PM2.5-induced premature deaths in 2014 in China, with a progressive order of magnitude increase from sources to receptors. Biomass fuels and coal provided similar contributions to health impacts. These findings are particularly true for rural populations, which contribute more to emissions and face higher premature death risks than urban populations. The impacts of both residential and nonresidential emissions are interconnected, and efforts are necessary to simultaneously mitigate both emission types.