Read the label! Energy Star appliance label awareness and uptake among U.S. consumers

The Energy Star label program to promote the diffusion of energy efficient home appliances is arguably the most significant government effort to reduce U.S. residential energy consumption. Program effectiveness requires that consumers are aware of the labeling scheme and also change their purchase decisions based on label information. This paper examines the factors associated with consumer awareness of the Energy Star label of recently purchased ‘white’ major appliances and the factors associated with the choice of Energy Star labeled appliances. The paper finds that household characteristics have a much stronger association with consumer awareness of labels than with the choice of Energy Star appliances. Renting the home, Hispanic ethnicity, being poor or near poor, and living in regions with lower ACEEE scores do, however, decrease the propensity for households to purchase Energy Star appliances. Eliminating these gaps in Energy Star appliance adoption would result in house electricity cost savings of $164 million per year and associated carbon emission reductions of about 1.1 million metric tons per year.     

A systematic approach in appliance disaggregation using k-nearest neighbours and naive Bayes classifiers for energy efficiency

One of the ways to achieve energy efficiency in various residential electrical appliances is with energy usage feedback. Research work done showed that with energy usage feedback, behavioural changes by consumers to reduce electricity consumption contribute significantly to energy efficiency in residential energy usage. In order to improve on the appliance-level energy usage feedback, appliance disaggregation or non-intrusive appliance load monitoring (NIALM) methodology is utilized. NIALM is a methodology used to disaggregate total power consumption into individual electrical appliance power usage. In this paper, the electrical signature features from the publicly available REDD data set are extracted by the combination of identifying the ON or OFF events of appliances and goodness-of-fit (GOF) event detection algorithm. The k-nearest neighbours (k-NN) and naive Bayes classifiers are deployed for appliances’ classification. It is observed that the size of the training sets effects classification accuracy of the classifiers. The novelty of this paper is a systematic approach of NIALM using few training examples with two generic classifiers (k-NN and naive Bayes) and one feature (power) with the combination of ON-OFF based approach and GOF technique for event detection. In this work, we demonstrated that the two trained classifiers are able to classify the individual electrical appliances with satisfactory accuracy level in order to improve on the feedback for energy efficiency.     

What's driving energy efficient appliance label awareness and purchase propensity?

The EU appliance energy consumption labeling scheme is a key component of efforts to increase the diffusion of energy-efficient household appliances. In this paper, the determinants of consumer knowledge of the energy label for household appliances and the choice of class-A energy-efficient appliances are jointly estimated using data from a large survey of more than 20,000 German households. The results for five major appliances suggest that lack of knowledge of the energy label can generate considerable bias in both estimates of rates of uptake of class-A appliances and in estimates of the underlying determinants of choice of class-A appliance. Simulations of the choice to purchase a class-A appliance, given knowledge of the labeling framework, reveal that residence characteristics and, in several cases, regional electricity prices strongly increase the propensity to purchase a class-A appliance, but socio-economic characteristics have surprisingly little impact on appliance energy-class choice.     

Energy labeling for electric fans in Malaysia

To reduce energy consumption in the residential sector, Malaysia Energy Commission is considering implementing energy labels for household electrical appliances including electric fans in 2005. The purpose of the energy labels is to provide the consumers a guideline to compare the size, features, price and efficiency of the appliance. This paper discusses the energy label for electric fans in this country based on Malaysian Standards developed by a technical committee that reviewed the performance of household electrical appliances. This study includes methodology for the calculation of the energy efficiency star rating and projected energy usage, performance requirements, details of the energy label and the requirements for the valid application in Malaysia. The label also can be adopted for other household electrical appliances with only slight modifications.     

How do household characteristics affect appliance usage? Application of conditional demand analysis to Japanese household data

Although both appliance ownership and usage patterns determine residential electricity consumption, it is less known how households actually use their appliances. In this study, we conduct conditional demand analyses to break down total household electricity consumption into a set of demand functions for electricity usage, across 12 appliance categories. We then examine how the socioeconomic characteristics of the households explain their appliance usage. Analysis of micro-level data from the Nation Survey of Family and Expenditure in Japan reveals that the family and income structure of households affect appliance usage. Specifically, we find that the presence of teenagers increases both air conditioner and dishwasher use, labor income and nonlabor income affect microwave usage in different ways, air conditioner usage decreases as the wife's income increases, and microwave usage decreases as the husband's income increases. Furthermore, we find that households use more electricity with new personal computers than old ones; this implies that the replacement of old personal computers increases electricity consumption.     

State identification of home appliance with transient features in residential buildings

Nonintrusive load monitoring (NILM) is crucial for extracting patterns of electricity consumption of household appliance that can guide users’ behavior in using electricity while their privacy is respected. This study proposes an online method based on the transient behavior of individual appliances as well as system steady-state characteristics to estimate the operating states of the appliances. It determines the number of states for each appliance using the density-based spatial clustering of applications with noise (DBSCAN) method and models the transition relationship among different states. The states of the working appliances are identified from aggregated power signals using the Kalman filtering method in the factorial hidden Markov model (FHMM). Thereafter, the identified states are confirmed by the verification of system states, which are the combination of the working states of individual appliances. The verification step involves comparing the total measured power consumption with the total estimated power consumption. The use of transient features can achieve fast state inference and it is suitable for online load disaggregation. The proposed method was tested on a high-resolution data set such as Labeled hIgh-Frequency daTaset for Electricity Disaggregation (LIFTED) and it outperformed other related methods in the literature.     

Economic feasibility for acquisition of efficient refrigerators in Brazil

Since 1993, the Brazilian National Program of Electricity Conservation has been developing the PROCEL Label Program, oriented towards helping consumers to buy more efficient home appliances. In this context, an energy savings of 1379 GWh and a reduction of 197 MW in the Brazilian demand in 2007 are estimated as resulting from efficiency labeling in refrigerators and freezers. This paper aims to evaluate the economic feasibility of purchasing labeled refrigerators instead of inefficient ones, from the consumer’s point of view, considering actual market conditions and buying in cash or financing. The evaluation of energy saving was done for 22 different models of refrigerators and the economy was calculated considering the retail price in the Brazilian market and two actual electricity tariffs, taking into account, respectively, high and low household electricity consumption. The effect of ambient temperature on refrigerator performance was evaluated in two conditions: according to the Brazilian standard for performance tests (32 °C) and using the average temperature of Southern Brazil (18 °C), the mildest region. The benefit in buying labeled refrigerators was evaluated using the Internal Rate of Return and the Payback Time for a cash flow during the appliance life, estimated as 16 years. The results indicate that for cash purchase, for any electricity tariff and for both ambient temperatures studied, the consumers are economically benefited buying labeled refrigerators instead of less efficient models. For credit purchases, in the evaluated conditions, high-tariff consumer typically gains selecting labeled refrigerator, on the other hand, for low-tariff consumer and in colder areas, it is economically advisable to buy less efficient appliances. Sensitivity analysis of energy tariff and financing conditions are presented.     

The barriers to energy efficiency in China: Assessing household electricity savings and consumer behavior in Liaoning Province

This article investigates the barriers to energy efficiency at the residential sector within one province in China and explores patterns of household electricity consumption. The article presents the results of a survey questionnaire distributed to more than 600 households in Liaoning Province, field research at various Liaoning government agencies, and research interviews of Liaoning government officials to determine the efficacy of their energy efficiency efforts in China. It then investigates the extent that electricity consumers have taken advantage of energy efficiency opportunities relating to more efficient lights, water heaters, appliances, air-conditioners and heaters, and better energy-efficiency labels. The article also assesses the degree that electricity users have become more aware about electricity prices and their levels of consumption, and touches on the connection between rising levels of income and electricity use. It concludes by providing recommendations for how to improve efforts to promote conservation and reduce electricity load growth in Liaoning Province and beyond.     

How moving home influences appliance ownership: a Passivhaus case study

Low carbon dwellings shift the focus to electricity consumption and appliances by significantly lowering space heating energy consumption. Using a UK Passivhaus (low carbon) case study, interviews and pre/post-move-in appliance audits were employed to investigate how moving home can change the appliance requirements of appliance-using practices. Changes in appliance ownership were due to differences in how appliance-using practices (e.g. cooking, laundering, homemaking) were being performed. Existing/new appliances complemented/conflicted with a new home on the basis of whether the social meanings of specific appliance-using practices (e.g. stylishness, convenience, thermal comfort, cleanliness) could be met. This was evident, when moving home more generally, by households buying new modern appliances and managing spatial constraints. More specifically, regarding Passivhaus, hosting and homemaking practices were performed in ways that met thermal comfort expectations, in addition to appliance purchasing also being influenced by a fear that the Passivhaus technologies could fail. Whilst skills and competences were needed to perform appliance-using practices, these were less prominent in influencing appliance ownership changes. Conclusions include reflections on how the elements of appliance-using practices change when moving home, as well as what adhering to building standards could mean for the standardisation of appliance-using practices and domestic life more generally.     

Energy use and appliance ownership in Ireland

This paper examines household energy use and appliance ownership in Ireland. Logit regression analyses on a large micro-dataset reveal how household characteristics can help explain the ownership of energy using appliances. Using OLS regression models, we explore the factors affecting residential energy demand conditional on appliance ownership. Results suggest that the methods of space and water heating employed by a household are even more important than electrical appliances in explaining domestic energy usage. However, the stock of appliances must be included in such models so that results will not be biased. The methods employed in this paper can be easily adopted for studies of household energy use in other countries where household expenditure survey data are available.     

Energy efficiency standards for refrigerators in Brazil: A methodology for impact evaluation

In Brazil energy efficiency standards for cold appliances was established in 2007. A specified single set of MEPS (minimum energy performance standards) for refrigerators, freezers and freezer refrigerators was implemented without evaluating its impacts and estimation of potential electricity savings. This paper presents a methodology for assessing the impacts of the Brazilian MEPS for cold appliances. It uses a bottom-up approach to estimate residential end-use consumption and to evaluate the energy saving potential for refrigerators. The household electricity consumption is projected by modeling appliance ownership using an econometric approach based on the recent household survey data. A cost–benefit analysis for more stringent standards is presented from the perspective of the society and electricity customers. The results showed that even considering the current market conditions (high discount rate for financing new efficient equipment) some MEPS options are advantageous for customers. The analysis also demonstrates significant cost-effective saving potential from the society perspective that could reach 21 TWh throughout the period of 2010–2030—about 25% of current residential consumption.     

Appliance energy labels and consumer heterogeneity: A latent class approach based on a discrete choice experiment in China

Given the growing concerns about environmental protection, a focus on energy label behavior is of particular public interest, as labels can communicate to consumers the sustainability of products. Based on a discrete choice experiment, we measure consumers' awareness and attitudes regarding refrigerators and washing machines. A mixed logit model is specified to quantify the attributes consumers look for when choosing the two electrical appliances. In the latent class model, four classes are observed. The results of the study reveal that the energy label program in China is effective. However, consumers do not always choose the energy efficient appliances, and their failure to do so is often related to an energy efficiency gap. Interestingly, both the largest groups for the refrigerator (33.17%) and washing machine (36.6%) tend to prefer the two electrical appliances with the lowest price. Both are foreign brands, with low energy label and larger overall capacity. Consumers are also willing to pay more for an improved energy grade label on the refrigerator (731.16 yuan) than on the washing machine (424.76 yuan). Suggestions regarding how to increase the probability of consumers choosing energy efficient appliances are also given in this paper.     

A run-around heat exchanger system to improve the energy efficiency of a home appliance using hot water

A significant portion of the energy consumed by many home appliances using hot water is used to heat cold supply water. Such home appliances generally are supplied water at a temperature lower than the ambient temperature, and the supply water is normally heated to its maximum operating temperature, often using natural gas or an electrical heater. In some cases, it is possible to pre-heat the supply water and save energy that would normally be consumed by the natural gas or electrical heater. In order to save the energy consumed by an appliance using water heater, a run-around heat exchanger system is used to transfer heat from the ambient to the water before an electrical heater is energized. A simple model to predict the performance of this system is developed and validated, and the model is used to explore design and operating issues relevant to the run-around heat exchanger system. Despite the additional power consumption by the fan and pump of the run-around heat exchanger system, the experimental data and analysis show that for some systems the overall energy efficiency of the appliance can be improved, saving about 6% of the energy used by the baseline machine.     

Modelling of electricity savings in the Danish households sector: from the energy system to the end-user

In this paper, we examine the value of investing in energy-efficient household appliances from both an energy system and end-user perspectives. We consider a set of appliance categories constituting the majority of the electricity consumption in the private household sector, and focus on the stock of products which need to be replaced. First, we look at the energy system and investigate whether investing in improved energy efficiency can compete with the cost of electricity supply from existing or new power plants. To assess the analysis, Balmorel, a linear optimization model for the heat and power sectors, has been extended in order to endogenously determine the best possible investments in more efficient home appliances. Second, we propose a method to relate the optimal energy system solution to the end-user choices by incorporating consumer behaviour and electricity price addition due to taxes. The model is non-exclusively tested on the Danish energy system under different scenarios. Computational experiments show that several energy efficiency measures in the household sector should be regarded as valuable investments (e.g. an efficient lighting system) while others would require some form of support to become profitable. The analysis quantifies energy and economic savings from the consumer side and reveals the impacts on the Danish power system and surrounding countries. Compared to a business-as-usual energy scenario, the end-user attains net economic savings in the range of 30–40 EUR per year, and the system can benefit of an annual electricity demand reduction of 140–150 GWh. The paper enriches the existing literature about energy efficiency modelling in households, contributing with novel models, methods, and findings related to the Danish case.     

Demographics,energy and our homes

The projected growth in households in the UK is a key factor in future domestic energy consumption, particularly electricity consumption. While every household needs a home and its heating, lighting and appliances, increasing incomes have historically led to significantly higher appliance ownership, higher expectations of levels of energy service and greater usage. In the past this trend was combined with increasing household numbers to drive growth in domestic electricity demand. Official projections for population growth and household composition indicate significant drivers for future growth in energy demand. Curbing this will require policies to reverse the tendency for energy–efficiency improvements to be overwhelmed by growing numbers of households, more widespread appliance ownership and increased service expectations.     

Accelerated electricity conservation in Juneau,Alaska: A study of household activities that reduced demand 25%

An avalanche destroyed the main hydroelectric transmission line to Juneau, Alaska in April, 2008. Diesel-generated electricity was substituted, causing electricity prices to increase 500% for 45 days. Electricity demand fell by 25% during the supply disruption. Most of the reduction occurred before the higher rates were implemented. Some conservation – about 8% of historic consumption – persisted after the transmission line was repaired and prices returned to normal. Consumers reduced energy use through a combination of new habits and technical improvements. A survey of residential consumers indicated that the average household undertook 10 conservation actions, with major changes in lighting, space heating, fuel switching, and water and appliance use. We propose a method for prioritizing conservation actions for promotion according to their impact in electricity savings (as a function of popularity, effectiveness, and persistence) and a dynamic framework for electricity use before, during, and after a supply disruption (i.e., both the magnitude and rates of change in electricity conservation).     

家电商场火灾蔓延特性的实验研究

根据家电商场火灾的实际特点,对货架和堆垛两种摆放形式的模拟家电标准组件进行了全尺寸的火灾实验研究.运用实验结果分析了火灾过程中不同阶段的燃烧特点,以及温度、辐射热流和火灾载荷等参数对火灾发展和蔓延规律的影响,并将最高辐射热值拟合为实验关联式,以揭示商场内家电火灾的内在规律和预测其发展趋势.同时获取火灾过程中的基础参数.     

On the adoption of electricity as a domestic source by Mozambican households

In Mozambique, domestic energy is often composed of a mix of sources, primarily used for lighting and cooking, with biomass and kerosene as more common sources. Electrification programs, intended to connect new consumers countrywide, have not significantly contributed either to the intensification of electricity consumption or to the reduction of the use of biomass in households. The choice of energy source is dependent on price and on the capability of the household to invest in energy-consuming appliances. Based on the data from a household survey carried out in Mozambique during 2002/03, this paper analyzes the geographic differences in unit expenditures for domestic energy and finds evidence of an inverted energy ladder with prices of useful energy units. The data show that biomass sources are often more expensive per unit of useful energy than higher-grade sources, supporting arguments favoring electrification as a poverty alleviation strategy. In addition, this study estimates the likelihood of poor households transitioning from biomass to electricity consumption based on various factors. Results indicate that income is not a determining factor in the transition, but wealth and the level of the Primary Energy Consumption Share (PECS) are as important factors as the nature of the energy mix.     

The optimization of demand response programs in smart grids

The potential to schedule portion of the electricity demand in smart energy systems is clear as a significant opportunity to enhance the efficiency of the grids. Demand response is one of the new developments in the field of electricity which is meant to engage consumers in improving the energy consumption pattern. We used Teaching & Learning based Optimization (TLBO) and Shuffled Frog Leaping (SFL) algorithms to propose an optimization model for consumption scheduling in smart grid when payment costs of different periods are reduced. This study conducted on four types residential consumers obtained in the summer for some residential houses located in the centre of Tehran city in Iran: first with time of use pricing, second with real-time pricing, third one with critical peak pricing, and the last consumer had no tariff for pricing. The results demonstrate that the adoption of demand response programs can reduce total payment costs and determine a more efficient use of optimization techniques.