Energy Efficiency最新文献

Building codes currently regulate energy efficiency in newly constructed buildings in Sweden. Alongside energy declarations, performance-based regulation specifying specific energy use requirements was introduced in Sweden in 2006. The requirements have been subsequently tightened to enhance energy performance. This study estimates the impact of these requirements on energy savings in Swedish multi-apartment buildings, relying on specific energy use data from energy performance certificates (EPCs). An estimated time trend indicates greater energy efficiency at a rate of 1.57% per year  for buildings with district heating and 1.09% per year for electrically heated buildings. After accounting for this trend, the results indicate that the implementation of performance-based regulation is associated with a 14.2% increase in energy efficiency for buildings with district heating and a 9.7% increase for those with electric heating. Moreover, the first tightened building codes generates an additional 2% increases in energy efficiency for district-heated buildings and an approximately 7.4% improvement for electrically heated buildings. However, there is no evidence to suggest that the second tightening of building codes have strong effects on further increasing energy efficiency. Furthermore, the effect of building codes is more substantial for buildings where actual energy use exceeds the mandated levels and modest for buildings with better energy performance. Alternatively, when studying the time trend of energy efficiency, I find a structural break with a significantly greater increase in efficiency over time during the period of regulation compared to before. In addition, findings in this study indicate evidence of the energy performance gap, where the estimated energy use from engineering models is substantially lower than the measured energy use for comparable construction.

The energy crisis, that began in 2021 has exacerbated energy poverty throughout Europe. Households with lower incomes, higher energy requirements, and less efficient homes and appliances are disproportionately affected by this crisis. These households often lack the financial capacity to upgrade outdated and inefficient appliances, such as refrigerators and washing machines. This then leads to increased energy costs or necessitates cutbacks in other energy uses such as heating, which in turn diminishes their residential comfort. In response to this issue, the Dutch government has implemented various strategies to mitigate energy poverty, including the 'White Goods Scheme'. The term ‘White Goods Schemes’ usually refers to a governmental initiative that offers financial incentives or assistance to consumers to encourage the purchase of new, energy-efficient household appliances. Despite such initiatives, there is hardly any research evaluating their effectiveness. This study examined the impact of the 'White Goods Scheme' in two regions of the Netherlands, by means of a questionnaire among residents (N = 541), comparing households that have made use of a white goods scheme (intervention group; N = 310) with households that have not yet made use of a white goods scheme (control group; N = 231). The findings show that the white goods schemes have the potential to improve residential comfort conditions, enhance physical health and reduce energy costs and financial concerns, yield better mental health. Yet, the causal mechanisms behind these connections need to be further scrutinised. While the scheme has demonstrated positive outcomes in terms of comfort, financial well-being and health, it is suggested that combining improvements like shallow retrofits and appliance schemes with other local support initiatives like energy advice is essential to address energy poverty, effectively.

Growing the proportion of electricity generated from renewable sources is an important goal. But periods of high energy demand are not always aligned with renewable supply, necessitating greater reliance on other sources such as fossil fuels. In Ireland, like many other countries, electricity demand typically peaks in the evening, driven largely by residential demand. Reducing or shifting household activities away from this evening peak period can thus increase the proportion of electricity generated from renewable sources. Understanding the flexibility potential of residential electricity demand requires knowing which household activities happen most during peak times, and what groups of people are most likely to perform them at those times, as well as understanding what might facilitate and motivate behaviour change. To investigate these questions, we use a behavioural science approach that is activity specific. Using a large dataset from an Irish tracking survey that adapts the day reconstruction method (Kahneman et al., 2004), we first record the time of day at which a range of activities – water heating and showering, laundry, dishwashing, and cooking, among others – take place. Focusing on the evening peak between 4 and 7 pm, we then investigate sociodemographic, household, and psychological variables associated with timing activities during this period rather than other times of day. We show that the factors associated with time of use (e.g., tariff structure, reported effort to avoid evening use, and household composition) vary by activity. We discuss the implications of our findings and note their value for demand side management mechanisms.

The 2023 revised Energy Efficiency Directive raises the EU energy efficiency target, making it binding for EU countries to collectively ensure an additional 11.7% reduction in energy consumption by 2030, compared to the 2020 reference scenario projections. The Directive highlights the exemplary role of the public sector in the energy efficiency improvement process, particularly with regard to buildings and public procurement. The regulation makes the use of energy performing contracting mandatory for the renovation of large public buildings and the promotion of exemplary EPC solutions. Given the growing popularity of the EPC model, in-depth research into various aspects of the EPC projects will become necessary. One of the important features of the EPC model is the achievement of guaranteed energy savings. With this comes risk, which is often transferred to energy service providers. The main purpose of the article is to analyze the provisions of the EED and Eurostat with regard to Polish regulations, in the context of the risk of guaranteed energy savings. The article conducted a literature review, an analysis of EED regulations, Eurostat guidelines and Polish regulations, guidelines, and contract models, in terms of the risk of guaranteed energy savings. In addition, Polish EPC project stakeholders were interviewed. The results show that the EED does not require ESCOs to bear the risk of guaranteed savings, which aims to ensure that EPC projects generate savings regardless of the obligated entity. The paths to this goal under EPC may vary. Nevertheless, it seems that from the point of view of public entities, the desirable model is to transfer this risk to the ESCO. Polish regulations, for example, in principle assume the transfer of this risk to the ESCO. In contrast, the detailed approach varies depending on the specific stakeholder group of EPC projects.

Solar photovoltaic (PV) technology is widely adopted in sub-Saharan regions due to abundant solar irradiation and unreliable grid infrastructure. However, the performance of roof-mounted PV systems is significantly influenced by the type of roofing material and surface coatings used. This review evaluates the thermal and performance implications of installing PV systems on four common roof types—green, clay tile, metal, and plastic tile under sub-Saharan climatic conditions. Findings indicate that green roofs reduce PV module temperatures by 1.5–3 °C and improve power output efficiency by up to 6%, while clay tile roofs offer up to 2.6 °C cooling compared to metal roofs, resulting in a 0.378 V increase in output voltage per module. Coated metal roofs with reflective pigments such as TiO₂ and Fe₂O₃ were found to improve PV performance by up to 10.4%. This review concludes that roof material selection and coating application play crucial roles in PV efficiency and system longevity, with green roofs offering the highest performance gains but facing cost and maintenance barriers. This review also highlights research gaps in the comparative thermal performance of coated metal roofs, clay tiles, and plastic tile roofs, especially under varying sub-Saharan climatic conditions.

Environmental and health risks stemming from traditional biomass fuel use remain a significant challenge in developing countries like Ethiopia. Improved cooking stoves have become a viable option to reduce these adverse effects; however, the adoption and use rates remain low. This study aims to analyze the performance of Mirt-improved stoves and identify the factors that determine its adoption in Northwest Ethiopia. A kitchen performance test (KPT) was conducted based on three days of repeated firewood measurement on randomly selected 15 Mirt-stove users and 20 three-stone stove user households. Additionally, 420 households were surveyed to identify factors determining the adoption of Mirt-stove. The data were analyzed using descriptive statistics and a binary logistic regression model. An independent t-test was also employed to analyze the kitchen performance test. The KPT results reveal that Mirt-stoves saved about 5.4 kg of firewood/injera baking session, which translates to about 777 kg (40.5%) reduction in firewood use per household per year compared with three-stone stoves. Besides, the KPT results show that Mirt-stoves reduce the time needed to bake injera compared to three-stone stoves by 23.5 min (28%), equivalent to an annual per capita time-saving of about 56.4 h. Further, estimates of the empirical results highlighted that household age, sex, education, family size, type of housing, availability of separate kitchens, access to credit, and access to information significantly and positively influence Mirt stove adoption. In contrast, distance from the stove market and fuel sources have significantly and negatively affected Mirt-stove adoption. The study suggests that fuel-efficient stoves like Mirt, if well adapted to local injera baking needs, can significantly contribute to forest conservations, improving livelihoods and lessening the workloads of women and children in fuelwood collection.

The energy crisis during Winter 2022–2023 placed energy high on the public agenda in Denmark, including a hitherto unseen focus on dynamic electricity prices. This paper identifies a normalisation of following electricity prices online during the crisis and changing practices accordingly, the aim of the paper being to learn from this normalisation theoretically as well as policy-wise. The paper is based on a quantitative survey (N = 1000) and in-depth qualitative interviews (n = 30). Results showed that among those who indicate that they have flexible electricity prices almost 70% say that they follow prices daily, and an even larger share indicate that they are more aware of the timing of their electricity use compared to one year ago. Furthermore, more than half of the households used timers on their washing machines and dishwashers to time-shift appliance-use. Through an analysis of variation in interest and practices of time-shifting, we construct a parameter that we call ‘care for the energy system’, which showed more correlations than households’ socio-economy. The qualitative interviews revealed how experiences and engagement in time-shifting of practices for some households was prompted by tight economic constraints and for other households by care for energy and interest in green energy consumption. The results suggest that variable prices coupled with media and authority communication can encourage people to care for the energy system through time-shifting. However, as economic incentives can have social consequences, price signals should be coupled with financial support for vulnerable households.

Energy poverty is a multidimensional phenomenon tied to discrimination, injustice, and energy aporophobia. The study’s motivation is to explore convergence among 31 European states from 2005 to 2022, using the log t regression test and club clustering. Energy poverty can be measured through three indicators: (i) arrears on utility bills (Arrears), (ii) ability to pay to keep the home adequately warm (Inadequately Warm), and (iii) the presence of a leaking roof, damp walls or rotten windows (Leaks). The novelty lies in quantifying energy poverty with these indicators and analyzing convergence in various regions, including the application of a robustness ordered-logit text and a slope-homogeneity test. The empirical results show that countries with the lowest Arrears scores, like Norway and Sweden, exhibit weak convergence, while those with the highest, such as Greece and Türkiye, demonstrate absolute convergence. For Inadequately Warm, Norway and Iceland also show absolute convergence, whereas for the Leaks indicator, Northern Europe performs better than Southern and Western regions. Geographically, Arrears reveal a core-periphery divide, while Inadequately Warm and Leaks highlight a North–South differentiation.

The residential sector in Ghana has been identified as an important group for energy efficiency programs in order to meet the country's growing energy demands and also tackle its power shortages. The total final energy consumption of the country stands at 47% for the residential sector, with an average of 31% and 7% for refrigerating and air conditioning, respectively. Improving energy efficiency in the residential sector will not only improve both local and global energy use but will also improve carbon emission reduction. Hence, to ensure that this energy efficiency is achieved, the country enacted four legislative instruments to regulate the importation of cooling appliances (refrigerating and air conditioning), lighting, and other household appliances. These legislative instruments are to ensure that these appliances meet the requirements of the minimum energy performance standards (MEPS). This study provides a quantitative performance evaluation of energy, energy savings, and carbon emissions through the adaptation of the minimum energy performance standards (MEPS), cooling appliance standardization, and labeling programs for Ghanaian households using the appliance and equipment climate impact calculator (MEPSY) modeling method. This quantitative evaluation (energy efficiency policy documents) is based on data acquired from governmental agencies responsible for the energy sector. The outcome revealed that the MEPS program in Ghana has yielded a total savings of over USD 3,100 in financial savings on electricity bills due to energy savings of 23,100KWh in the household sector from 2010 to 2020, while a total of over 12,650GWh of electricity savings was made, translating into financial savings of over USD 2 billion in electricity bill savings with a carbon reduction of 6.5 million tons within the same period at the national level.