Yan Bai

Evaluating the net energy-saving effect of a mandatory energy efficiency labeling system implemented uniformly at a national scale remains a persistent challenge in policy quantification. Household refrigerators in China have been subject to mandatory energy efficiency labeling since 2005, with the third revision enacted in 2016, tightening the Grade 1 efficiency threshold by approximately 40%. Because the policy was rolled out simultaneously nationwide, no untreated control group exists, rendering conventional difference-in-differences approaches inapplicable and impeding the causal attribution of energy savings to the labeling system. This study employs an interrupted time series (ITS) design, with the 2016 revision designated as the policy breakpoint, to estimate the net effect of the label update on refrigerator energy consumption. Using a segmented linear regression model with Newey–West HAC robust standard errors (lag = 1), the fully adjusted specification identifies a statistically significant negative immediate change of approximately 0.069 kWh in daily energy consumption at the policy implementation point (p < 0.001), although the estimated magnitude is sensitive to the model specification. The flow-based cumulative electricity saving associated with the 2016–2025 period is estimated at 4.84 billion kWh, equivalent to 1.49 million tonnes of coal equivalent and a CO₂ emission reduction of 4.31 million tonnes. The findings provide conditional evidence that the label revision was associated with lower refrigerator energy consumption and improved product-level energy performance.

With the rapid adoption of dishwashers in China’s households, the consequent growth in energy and water consumption presents new challenges for energy conservation, emission reduction, and water resource management in China. To address this, this study adopts the concept of the energy–water nexus to analyze the factors influencing dishwasher usage behaviors and quantifies the co-benefits of energy and water conservation through questionnaire surveys, establishing a household dishwasher energy and water accounting model. The findings reveal that dishwasher usage behaviors are influenced by dietary habits—greater oil usage in cooking leads to higher frequency of use and a greater tendency to select intensive wash modes, thereby increasing energy and water consumption. It is projected that by 2030, promoting energy-efficient dishwashers could achieve annual savings of approximately 390 million kWh of electricity and 4 million m³ of water. Furthermore, shifts in dietary habits offer significant potential for achieving co-benefits in energy and water conservation. Encouraging households to adopt low-oil cooking practices could yield additional annual savings of 5.14 billion kWh of electricity and 9.57 million m³ of water. Based on these results, this paper puts forward policy recommendations to facilitate the coordinated management of household energy and water conservation.

Under the multiple pressures of intensifying global climate change disruption and rapid economic growth, China has become one of the countries facing the most serious water scarcity problems. Based on the ISO 14046 standard and the framework of water scarcity footprint theory, this study will break through the static limitations and lack of dimensions of traditional characteristic factors (i.e., water stress) and construct a water stress evaluation index system that combines nature, economy, and society. The results indicate that in recent years, regional water stress in China has exhibited significant spatiotemporal variations and spatial clustering, primarily driven by composite factors, with an overall decreasing trend. Among them, Shanghai is the highest-pressure area and Shaanxi is the lowest-pressure area, which is mainly due to the spatial projection of the coupling effect of multi-dimensional factors. In addition, the obstacle degree analysis method shows that indicators such as the utilization rate of water resource development constitute cross-regional constraints. To this end, all regions should make efforts to regulate and control the water use structure, introduce water-saving technologies, and strengthen water-saving publicity according to their needs. Therefore, this study not only provides a scientific basis for in-depth understanding of the distribution law and influencing mechanism of water stress but also provides an important reference for the rational allocation and sustainable use of water resources by upgrading the characteristic factors to system control signals.

In the context of increasing water scarcity, improving industrial water efficiency and resource management has become an urgent need, particularly in water-intensive sectors such as the cement industry. Based on the Water Life Cycle Assessment (WLCA) framework, in this study, a comprehensive assessment of water use, consumption, reuse, and wastewater discharge during cement production was conducted, and paths were proposed for improving water efficiency. Unlike traditional water footprint assessments, which primarily focus on measuring water consumption, the WLCA integrates a holistic analysis of the operational status of water systems. The research results show that for cement production in the Yellow River Basin, the waste heat power generation system accounts for the highest proportion of water consumption (65%), with its circulating cooling unit functioning as the core water-related subsystem. A large quantity of daily circulating cooling wastewater can be reused in production after treatment. Significant differences exist in unit product water consumption among enterprise types: clinker and cement production enterprises (0.18–0.30 m³/t) have higher water consumption than cement grinding stations (0.02–0.05 m³/t), and some enterprises hold considerable water-saving potential. Wastewater recovery and treatment technologies can markedly reduce water wastage. Meanwhile, waste heat recovery technologies improve energy utilization efficiency and indirectly lower water cooling demand. Additionally, waste co-processing technologies reduce virtual water consumption by replacing part of the coal used in cement production. This research provides practical technical solutions for water conservation and resource optimization in the cement industry, facilitating improvements in water efficiency management.

Considering the challenges of increasing global energy scarcity and intensifying environmental problems, energy conservation in end-use energy-consuming products has become critical. In this study, we focused on household refrigerators and analyzed the individual characteristics, energy-saving awareness, and usage behaviors of Chinese refrigerator users; discussed the influence of individual characteristics and energy-saving awareness of users on refrigerator usage behavior; and evaluated the energy-saving potential with improved user behavior. The results showed that the energy-saving awareness or usage behavior of refrigerator users requires adjustment and improvement to avoid significant energy wastage. Additionally, a strong correlation was found between education, product energy efficiency level selection, age, and user behavior. Optimizing purchase choices among existing refrigerator energy efficiency grades would result in a national energy-saving potential of up to 9.31 × 10¹⁰ kW·h annually, whereas adjusting the door opening frequency and duration of some users could achieve annual energy savings of 6.14 × 10¹⁰ kW·h and 4.47 × 10¹⁰ kW·h, respectively. This study comprehensively evaluated the energy-saving potential of refrigerators from two aspects: market research and laboratory quantitative analysis. The results highlight that the government, enterprises, and individuals should pay attention to the energy-saving potential of refrigerators and actively take effective measures to promote the realization of the “dual carbon” goal.

The sustainable management of domestic water use is essential for China’s ongoing development. Despite its significance, public service water use, especially within the hotel industry, is frequently neglected. This industry not only accounts for substantial water usage, but it has also witnessed exponential growth over the past decade. In light of this, this study developed a survey on the water demand and behavior of hotel consumers and built a water consumption model to analyze the different characteristics of the total volume of water used by various water appliances. Furthermore, by dividing the hierarchical intervals of each water-use behavior, it identified the main water-saving target of each water appliance. The results showed that the daily water demand of each consumer in hotels ranged from 45 to 141 L/(person·d). Among the various water-use appliances, faucets had the highest proportion of excessive water use, reaching nearly 40%, which implies a relatively large potential for saving water. Additionally, showers were the next major contributors to water consumption, whereas the proportion of excessive water use for water closets was relatively small. Owing to different habits, there is also variability in the main groups of people targeted for water conservation across water appliances, with females having the largest potential for water consumption in hotels. The results of this study can provide greatvaluable insights for enhancing water-use efficiency in hotels and standardizing water management practices within the industry.

Colleges and universities are a typical service water consumers in China, i.e., with a dense population, single structure, and regular water use. This means it is crucial to strengthen the management of their water use behavior. In this paper, first of all, the main water devices and water use behavior of students were elucidated by investigating and analyzing the structure and scenarios of water use in colleges and universities. Then, a model of water use behavior of college students with sociodemographic and environmental characteristics was constructed based on the theory of planned behavior (TPB). By investigating and analyzing the water use behavior, the theoretical judgment of the improved TPB model that “behavior is the result of interaction between individual and environmental characteristics” was proved, which provides a reference for studying the water demand requirements of college students and supports scientific water-use management in colleges, our results also help the exploration of potential water-saving solutions in order to construct water-conservative colleges and universities.

Water-efficient products, a key component of water-saving technology, are widely installed and utilized in all sectors of society. Due to China’s extensive and varied use of this product, advancements in effectiveness and quality will significantly enhance people’s standard of living. In recent years, manufacturers, corporate purchasers, and individual customers have given more attention to the quality of these items due to the spike in local market and export demands for water-efficient products in China. It has been a pressing problem to find a practical solution for increasing product quality in a reasonable and scientific manner. In order to build a DECIA quality improvement model for water-efficient product quality that is quantifiable and technically practical, this paper investigates how to improve the quality of smart water closets based on six-sigma management. Thus, the development of a water-efficient industry can be green and sustainable.