Residential energy efficiency interventions: A meta-analysis of effectiveness studies

BACKGROUND: The residential sector releases around 17% of global greenhouse gas emissions and making residential buildings more energy efficient can help mitigate climate change. Engineering models are often used to predict the effects of residential energy efficiency interventions (REEI) on energy consumption, but empirical studies find that these models often over-estimate the actual impact of REEI installation. Different empirical studies often estimate different impacts for the same REEI, possibly due to variations in implementation, climate and population. Funding for this systematic review was provided by the evaluation function at the European Investment Bank Group. OBJECTIVES: The review aims to assess the effectiveness of installing REEIs on the following primary outcomes: energy consumption, energy affordability, CO2 emissions and air quality indices and pollution levels. SEARCH METHODS: We searched CAB Abst, Econlit, Greenfile, Repec, Academic Search Complete, WB e-lib, WoS (SCI and SSCI) and other 42 databases in November 2020. In addition, we searched for grey literature on websites, checked the reference lists of included studies and relevant reviews, used Google Scholar to identify studies citing included studies, and contacted the authors of studies for any ongoing and unpublished studies. We retrieved a total of 13,629 studies that we screened at title and abstract level, followed by full-text screening and data extraction. SELECTION CRITERIA: We included randomised control trials, and quasi-experimental studies that evaluated the impact of installing REEIs anywhere in the world and with any comparison. DATA COLLECTION AND ANALYSIS: Two independent reviewers screened studies for eligibility, extracted data and assessed risk of bias. When more than one included study examined the same installation of the same type of REEI for a similar outcome, we conducted a meta-analysis. We also performed subgroup analyses. MAIN RESULTS: A total of 16 studies were eligible and included in the review: two studies evaluated the installation of efficient lighting, three studies the installation of attic/loft insulation, two studies the installation of efficient heat pumps, eight studies the installation of a bundle of energy efficiency measures (EEMs), and one study evaluated other EEMs. Two studies, neither appraised as having a low risk of bias, find that lighting interventions lead to a significant reduction in electricity energy consumption (Hedges' g = −0.29; 95% confidence interval [CI]: −0.48, −0.10). All the other interventions involved heating or cooling, and effects were synthesizised by warmer or colder climate and then across climates. Four studies examined the impact of attic/loft insulation on energy consumption, and two of these studies were appraised as having a low risk of bias. Three studies took place in colder climates with gas consumption as an outcome, and one study took place in a warmer climate, with the electricity consumption (air conditioning) as the outcome. The average impact across all climates was small (Hedges' g = 0.04; 95% CI: −0.09, 0.01) and statistically insignificant. However, two of the studies appear to have evaluated the effect of installing small amounts (less than 75 mm) of insulation. The other two studies, one of which was appraised as low risk of bias and the other involving air conditioning, found significant reductions in consumption. Two studies examined the impact of installing electric heat pumps. The average impact across studies was not statistically significant (Hedges' g = −0.11; 95% CI: −0.41, 0.20). However, there was substantial variation between the two studies. Replacing older pumps with more efficient versions significantly reduced electricity consumption in a colder climate (Hedges' g = −0.36; 95% CI, −0.57, −0.14) in a high risk of bias study. However, a low risk of bias study found a significant increase in electricity consumption from installing new heat pumps (Hedges' g = 0.09; 95% CI, 0.06, 0.12). Supplemental analyses in the latter study indicate that households also used the heat pumps for cooling and that the installed heat pumps most likely reduced overall energy consumption across all sources—that is, households used more electricity but less gas, wood and coal. Seven studies examined bundled REEIs where the households chose which EEMs to install (in five studies the installation occurred after an energy audit that recommended which EEMs to install). Overall, the studies estimated that installing an REEI bundle is associated with a significant reduction in energy consumption (Hedges' g = −0.36; 95% CI, −0.52, −0.19). In the two low risk of bias studies, conducted with mostly low-income households, installed bundles reduced energy consumption by a statistically significant amount (Hedges' g = −0.16; 95% CI, −0.13, −0.18). AUTHORS' CONCLUSIONS: The 16 included studies indicate that installing REEIs can significantly reduce energy consumption. However, the same type of REEI installed in different studies caused different effects, indicating that effects are conditional on implementation and context. Exploring causes of this variation is usually not feasible because existing research often does not clearly report the features of installed interventions. Additional high quality impact evaluations should be commissioned in more diverse contexts (only one study was conducted in either Asia or Africa—both involved lighting interventions—and no studies were conducted in South America or Southern Europe)

PROTOCOL: Residential energy efficiency interventions: An effectiveness systematic review

This review aims to identify, appraise and synthesise the evidence available on the effectiveness of energy efficiency measure installations, including those bundled with behavioural interventions. The synthesis will estimate the overall impact of these interventions as well as examine possible causes of variation in impacts. We will also attempt to assess the cost-effectiveness of residential energy efficiency interventions

Talking About Texas: Texas Business Review and 75 Years of Change

Among the projects listed in 1926 for the newly established Bureau of Business Research (BBR) at the University of Texas at Austin was the "issuance of a publication setting forth the economic health of the state." And so began Texas Business Review (TBR) in April 1927. This special 75th anniversary issue hopefully provides an insightful and enjoyable look back that will perhaps enhance our view on where the twenty-first century is going.IC2 Institut

Peptidoglycan synthesis machinery in Agrobacterium tumefaciens during unipolar growth and cell division.

UnlabelledThe synthesis of peptidoglycan (PG) in bacteria is a crucial process controlling cell shape and vitality. In contrast to bacteria such as Escherichia coli that grow by dispersed lateral insertion of PG, little is known of the processes that direct polar PG synthesis in other bacteria such as the Rhizobiales. To better understand polar growth in the Rhizobiales Agrobacterium tumefaciens, we first surveyed its genome to identify homologs of (~70) well-known PG synthesis components. Since most of the canonical cell elongation components are absent from A. tumefaciens, we made fluorescent protein fusions to other putative PG synthesis components to assay their subcellular localization patterns. The cell division scaffolds FtsZ and FtsA, PBP1a, and a Rhizobiales- and Rhodobacterales-specific l,d-transpeptidase (LDT) all associate with the elongating cell pole. All four proteins also localize to the septum during cell division. Examination of the dimensions of growing cells revealed that new cell compartments gradually increase in width as they grow in length. This increase in cell width is coincident with an expanded region of LDT-mediated PG synthesis activity, as measured directly through incorporation of exogenous d-amino acids. Thus, unipolar growth in the Rhizobiales is surprisingly dynamic and represents a significant departure from the canonical growth mechanism of E. coli and other well-studied bacilli.ImportanceMany rod-shaped bacteria, including pathogens such as Brucella and Mycobacteriu, grow by adding new material to their cell poles, and yet the proteins and mechanisms contributing to this process are not yet well defined. The polarly growing plant pathogen Agrobacterium tumefaciens was used as a model bacterium to explore these polar growth mechanisms. The results obtained indicate that polar growth in this organism is facilitated by repurposed cell division components and an otherwise obscure class of alternative peptidoglycan transpeptidases (l,d-transpeptidases). This growth results in dynamically changing cell widths as the poles expand to maturity and contrasts with the tightly regulated cell widths characteristic of canonical rod-shaped growth. Furthermore, the abundance and/or activity of l,d-transpeptidases appears to associate with polar growth strategies, suggesting that these enzymes may serve as attractive targets for specifically inhibiting growth of Rhizobiales, Actinomycetales, and other polarly growing bacterial pathogens

Label-free fluorescence lifetime and second harmonic generation imaging microscopy improves quantification of experimental renal fibrosis

All forms of progressive renal diseases develop a final pathway of tubulointerstitial fibrosis and glomerulosclerosis. Renal fibrosis is usually quantified using histological staining, a process that is time-consuming and pathologist dependent. Here we develop a fast and operator-independent method to measure fibrosis utilizing the murine unilateral ureteral obstruction model which manifests a time-dependent fibrotic increase in obstructed kidneys while the contralateral kidneys are used as controls. After ureteral obstruction, kidneys were analyzed at 7, 14, and 21 days. Fibrosis was quantified using fluorescence lifetime imaging (FLIM) and second harmonic generation (SHG) in a Deep Imaging via Enhanced photon Recovery deep tissue imaging microscope. This microscope was developed for deep tissue along with second and third harmonic generation imaging and has extraordinary sensitivity toward harmonic generation. SHG data suggest the presence of more fibrillar collagen in the obstructed kidneys. The combination of short-wavelength FLIM and SHG analysis results in a robust assessment procedure independent of observer interpretation and let us create criteria to quantify the extent of fibrosis directly from the image. Thus, the FLIM-SHG technique shows remarkable improvement in quantification of renal fibrosis compared to standard histological techniques