美国能源之星计划最新动态分析

能源之星计划是美国用能产品节能管理措施的重要组成部分,对世界各国的节能法规和标准产生了重要影响,在一定程度上,产品获得能源之星认证已成为进入发达国家市场的一个通行证。能源之星计划目前覆盖商业设备、家用电器、办公室设备、照明产品、房屋建材产品5大类60类终端耗能产品。2009年,新颁布了电视机和LED灯等5类产品标准,包括洗碗机、洗衣机、计算机、显示器等13类产品的标准陆续生效,这些新的标准将对我国相关产品出口到美国造成一定影响。生产商获取能源之星认证需要3个步骤:确定产品是否已符合或者能够符合能源之星标准;制造商成为能源之星合作伙伴;履行能源之星合作伙伴的义务。美国能源之星计划与我国能效标准、欧盟EuP/ErP指令三者相比,能源之星的要求较其他两者更严,规定的技术项目也更多。相比之下,我国能效标准水平较低,仍存在提升的空间,同时在实施过程中尚存在法律法规不够健全、行业自律性差、公众能效意识较低等一些现实障碍。     

Quantity and electricity consumption of plug load equipment on a university campus

The percent of energy consumed by plug load equipment in commercial buildings is on the rise. Research conducted in the past has included surveying plug load equipment, measuring plug load electricity consumption and equipment operating patterns, and studying plug load reduction solutions in office buildings, but plug load energy use across other building types is poorly understood. A university campus, which houses many building types, presents a unique opportunity to understand plug load profiles across building types. In this study, an equipment inventory was performed in 220 buildings on Stanford University’s campus, totaling 8,901,911 ft² of building space and encompassing lab buildings, office buildings, recreation facilities, public space, and service buildings. Within these buildings, 110,529 pieces of plug load equipment were recorded. Energy consumption estimates were developed from published values and used to evaluate the aggregate plug load energy consumption of this equipment by equipment type and by building type. In total, it is estimated that the plug loads from these buildings consume nearly 50 million kWh per year and comprise 32% of the electricity consumption of the buildings surveyed. This data can be used to better target energy conservation efforts throughout multiple sectors.     

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.     

Status and future directions of the Energy Star program

In 1992 the US Environmental Protection Agency (EPA) introduced Energy Star^®, a voluntary labeling program designed to identify and promote energy-efficient products, in order to reduce carbon dioxide emissions. Since then, the EPA, now in partnership with the US Department of Energy (DOE), has expanded the program to cover nearly the entire buildings sector, spanning new homes, commercial buildings, residential heating and cooling equipment, major appliances, office equipment, commercial and residential lighting, and home electronics. This paper is based on our experience since 1993 in providing technical support to the Energy Star program. We provide a snapshot of the Energy Star program in the year 2000, including a general overview of the program, its accomplishments, and the possibilities for future development.     

A review on energy,economical, and environmental benefits of the use of CHP systems for small commercial buildings for the North American climate

The use of combined heating and power (CHP) systems to produce both electricity and heat is increasing rapidly due to their high potential of reducing primary energy consumption (PEC), cost, and emissions in domestic, commercial, and industrial applications. In addition to producing both electricity and heat, CHP systems can be coupled with vapor compression systems to provide cooling. This paper analyzes a natural gas engine CHP system together with a vapor compression system for different American climate zones. Performance is measured in terms of operational costs, PEC, and carbon dioxide emissions as a percent of a reference building. The objective of this paper is to compare the performance of a CHP system operating 24 h a day with a system that only operates during typical office hours. Furthermore, the system is optimized based on reducing PEC, minimizing costs, and reducing emissions. In addition, the benefits of CHP systems based on the Energy Star program and the Leadership in Energy and Environmental Design (LEED) program are presented. Results show that, in general, it is more beneficial to operate the CHP system during typical office hours than to operate the system 24 h a day. Also, the CHP system performance strongly depends on the location where it is installed. In addition to reductions in cost, primary energy, and emissions, CHP systems can help achieve the Energy Star label for commercial office buildings and help obtain LEED points that go toward achieving LEED certification status. Copyright © 2009 John Wiley & Sons, Ltd.     

Impact of voluntary green certification on building energy performance

Credible estimates of energy savings from green buildings are critical for policy makers to examine the cost and benefit of various incentives intended to encourage commercial buildings to go green (e.g. expedited construction permits, government grants, and property tax incentives). Yet, data limitations have hindered reliable estimations. Filling this gap, this study uses a large panel dataset on energy consumption for commercial buildings in Phoenix metropolitan area, Arizona. By tracking building occupants' monthly energy consumption before and after the building's certification as an Energy Star building, we provide new estimates of the environmental gains from private investment in green real estate. Results show that for occupants that occupy space in a certified building in both the pre-certification and post-certification periods, occupants in Energy Star buildings consume 8% less energy. This empirically robust estimate of potential benefit from green-certification provides a quantifiable benchmark against which green-promoting policies can be measured. We also document evidence of heterogeneous treatment effects. Energy savings differ by the building's initial certification points and the building's baseline energy consumption. These results are useful for policy makers to identify targets for green certification.     

Energy savings assessment for digital-to-analog converter boxes

The Digital Television (DTV) Converter Box Coupon Program was administered by the U.S. government to subsidize purchases of digital-to-analog converter boxes, with up to two $40 coupons for each eligible household. In order to qualify as Coupon Eligible Converter Boxes (CECBs), these devices had to meet a number of minimum performance specifications, including energy efficiency standards. The Energy Star Program also established voluntary energy efficiency specifications that are more stringent than the CECB requirements. In this study, we measured the power and energy consumptions for a sample of 12 CECBs (including 6 Energy Star labeled models) in-use in homes and estimated aggregate energy savings produced by the energy efficiency policies. Based on the 35 million coupons redeemed through the end of the program, our analysis indicates that between 2500 and 3700 GWh per year are saved as a result of the energy efficiency policies implemented on digital-to-analog converter boxes. The energy savings generated are equivalent to the annual electricity use of 280,000 average US homes.     

Is space heating in offices really necessary?

New office buildings in Sweden are thoroughly insulated due to the Swedish building code. This code, however, does not consider the type of activity occurring in the building. This means that the heating equipment is designed as if no activity at all is going on. In modern offices there is a lot of equipment installed which uses electricity. This electricity is converted into heat which can be utilized for heating the premises, mostly in a direct way but also by the use of exhaust-air heat-pumps or heat exchangers. This paper deals with a modern office building plus office hotel complex located in Linköping, Sweden, about 200 km south of Stockholm. The tenants deal with the design of hard- and software for computers. The lighting and computers in the building use electricity which converts into heat. In this paper, it is shown that this electricity is all that is needed during normal conditions, i.e. when people work in the building. The building is also equipped with a district-heating system, which is designed as if no activity goes on in the building, so subsequently the heating equipment is larger than it need be. In this special case, it might have been better to install an electric heating device for hot-water heating and very cold winter conditions, instead of using district heating. This is so even if district heat is about half the unit price compared with that due to the dissipation of electricity. At present, when district heating is used, no measures for saving heat can be profitable due to the low district-heating price. The fact is that the tenants complain of too much heat instead of too little: the prevailing indoor temperature was about 24° C in January 1990 even though 20° C would have been sufficient. There is subsequently a need for a properly working regulation system. The one currently in use is designed to a modern standard, but is not able to maintain temperatures at a modest level.     

E1290．3．5／0．96离心鼓风机节能改造

节能降耗已成为企业的生存之本,制药企业的透平机（大型鼓风机）是电耗最大的设备之一。在满足生产工艺要求前提下,对E1290．3．5／0．96型离心机进行系统性的节能改造后,相比于E1420型节电30％以上,可为公司节约电费300多万元／a,改造节能成效显著。     

Electricity used by office equipment and network equipment in the US

In spite of the recent explosive growth in the use of office and network equipment, there has been no recent study (until this one) that estimates in detail how much electricity is consumed by that equipment in the United States.In this study, we examined energy use by office equipment and network equipment at the end of 1999. We classified office equipment into 11 types; for each type we estimated annual energy consumption for residential, commercial, and industrial use by combining estimates of stock, power requirements, usage, and saturation of power management. We also classified network equipment into six types and estimated the annual energy consumption for each type.We found that total direct power use by office and network equipment is about 74 TWh per year, which is about 2% of total electricity use in the US. When electricity used by telecommunications equipment and electronics manufacturing is included, that figure rises to 3% of all electricity use. More than 70% of the 74 TWh/year is dedicated to office equipment for commercial use. We also found that power management currently saves 23 TWh/year, and complete saturation and proper functioning of power management would achieve additional savings of 17 TWh/year. Furthermore, complete saturation of night shutdown for equipment not required to operate at night would reduce power use by an additional 7 TWh/year.Finally, we compared our current estimate with our 1995 forecast for 1999. We found that the total difference between our current estimate and the previous forecast is less than 15% and identified the factors that led to inaccuracies in the previous forecast. We also conducted a sensitivity analysis of the uncertainties in our current forecast and identified the data sets that have the largest impact on our current estimate of energy use.     

Bottom–Up Energy Analysis System (BUENAS)—an international appliance efficiency policy tool

The Bottom–Up Energy Analysis System (BUENAS) calculates potential energy and greenhouse gas emission impacts of efficiency policies for lighting, heating, ventilation, and air conditioning, appliances, and industrial equipment through 2030. The model includes 16 end use categories and covers 11 individual countries plus the European Union. BUENAS is a bottom–up stock accounting model that predicts energy consumption for each type of equipment in each country according to engineering-based estimates of annual unit energy consumption, scaled by projections of equipment stock. Energy demand in each scenario is determined by equipment stock, usage, intensity, and efficiency. When available, BUENAS uses sales forecasts taken from country studies to project equipment stock. Otherwise, BUENAS uses an econometric model of household appliance uptake developed by the authors. Once the business as usual scenario is established, a high-efficiency policy scenario is constructed that includes an improvement in the efficiency of equipment installed in 2015 or later. Policy case efficiency targets represent current “best practice” and include standards already established in a major economy or well-defined levels known to enjoy a significant market share in a major economy. BUENAS calculates energy savings according to the difference in energy demand in the two scenarios. Greenhouse gas emission mitigation is then calculated using a forecast of electricity carbon factor. We find that mitigation of 1075 mt annual CO₂ emissions is possible by 2030 from adopting current best practices of appliance efficiency policies. This represents a 17 % reduction in emissions in the business as usual case in that year.     

Setting the standard? A framework for evaluating the cost-effectiveness of building energy standards

The adoption rate and stringency of building energy standards in the U.S. have been increasing since the mid-1990s as a result of the Energy Policy Act mandate of 1992 (EPAct). Current evidence on the energy savings that accrue from commercial building energy standards is based on engineering simulations, which do not account for realized behaviour once a standard is actually adopted. This paper uses quasi-experimental variation in commercial building energy standard adoptions to estimate their effect on realized electricity consumption and cost-effectiveness. In states induced by EPAct to adopt an energy standard where all new nonresidential construction was erected under a commercial standard, electricity consumption per service worker is lower by about 12%, and total commercial electricity consumption is lower by 10%. Including early adopters and never-adopters to the analysis leads to a downward bias in the treatment effect. The realized electricity savings in the EPAct states represent three quarters of predicted simulated savings, and electricity saved in 2010 came at a cost of approximately 7.7 cents per kWh.     

Hybrid Hydrogen Home Storage for Decentralized Energy Autonomy

As the share of distributed renewable power generation increases, high electricity prices and low feed-in tariff rates encourage the generation of electricity for personal use. In the building sector, this has led to growing interest in energy self-sufficient buildings that feature battery and hydrogen storage capacities. In this study, we compare potential technology pathways for residential energy storage in terms of their economic performance by means of a temporal optimization model of the fully self-sufficient energy system of a single-family building, taking into account its residential occupancy patterns and thermal equipment. We show for the first time how heat integration with reversible solid oxide cells (rSOCs) and liquid organic hydrogen carriers (LOHCs) in high-efficiency, single-family buildings could, by 2030, enable the self-sufficient supply of electricity and heat at a yearly premium of 52% against electricity supplied by the grid. Compared to lithium-ion battery systems, the total annualized cost of a self-sufficient energy supply can be reduced by 80% through the thermal integration of LOHC reactors and rSOC systems.     

Transient simulation and techno-economic assessment of a near-zero energy building using a hydrogen storage system and different backup fuels

Proposing a cost-effective off-grid Hybrid Renewable Energy System (HRES) with hydrogen energy storage with a minimum CO2 emission is the main objective of the current study. The electricity demand of an office building is considered to be supplied by Photovoltaic Panels and wind turbines. The office building, modeled in Energy Plus and Open studio, has annual electricity consumption of 500 MWh electricity. 48.9% of the required electricity can be generated via renewable resources. Considering a system without energy storage, the remaining amount of electricity is generated from diesel generators. Hence, for reducing CO2 emission and fuel costs, a hydrogen energy storage system (ESS) is integrated into the system. Hydrogen ESS is responsible for supplying 38.6% of the demand electricity, which means that it can increase the energy supplying ability of the system from 48.9% to 87.5%. In addition to analyzing the application of the hydrogen storage system, the effect of four different kinds of fuel is considered as well. effects of Natural gas, Diesel, Propane, and LPG on the system's application are investigated in this study. Results indicate that natural gas emits less amount of CO2 compared to other fuels and also has a fuel cost of 3054 $/year, while hydrogen ESS is available. For the renewable system without ESS, the fuel cost rises to 10,266 $/year. However, liquid gas, Propane, and LPG have better performance in terms of CO2 emission and fuel cost, respectively.     

Energy use in commercial buildings in Hong Kong

The energy performances of 20 commercial buildings, covering the common types found in Hong Kong, have been studied. The monthly electricity billing data as well as the results from computer modeling were analyzed. Energy signatures for the commercial buildings were found by a method similar to PRISM. Correlation equations of energy use with building envelope parameters, such as OTTV, building size, envelope heat gain, and the annual chiller-load were derived. The results are useful for building envelope design, energy audit, and legislative control of energy use in commercial buildings.     

Measurement and analysis of product energy efficiency to assist energy star criteria development: An example for desktop computers

The Energy Star labeling program contributes to reducing economic and environmental impacts. Although product-specific criteria for the label are developed by taking into account potential energy savings, more robust criteria need to be developed to minimize energy consumption (and consequential global warming potential (GWP)). The objectives of this study are: (i) to measure what we refer to as the technical and cost efficiencies of products with respect to the relative Energy Star criteria achievement rate and GWP, respectively; and (ii) to analyze the relationship between these efficiencies and product design features, using stochastic frontier analysis (SFA) and data envelopment analysis (DEA). As an example, these analyses are applied to data for desktop computers. The results indicate that desktop computer manufacturers currently achieve energy savings that exceed those required by the Energy Star label. The principal product design features affecting the efficiencies are primarily the efficiency and power capacity of the power supply and the number of cores in the central processing unit. This study can help the program develop more robust criteria that ultimately reduce GWP and can provide guidance to manufacturers to strategically improve energy efficiency.     

Power-to-gas leverage effect on power-to-heat application for urban renewable thermal energy systems

High Renewable Energy Sources (RES) share in energy systems entails environmental advantages in its use but drawbacks in its distribution, management and effectiveness. The interconnection between electricity, heat and transport sector seems to be a comprehensive answer. Its actual link is on-going and, currently, involves electricity and heat. Indeed, Power to Heat (P2H) is the strategy of meeting the heating demand by supplying electricity to feed Heat Pump (HP). Their higher efficiency compared to fossil fuel boilers requires a further check in the quality of the heating demand to meet, i.e. the temperature levels. Great part of current building stock calls for High Temperature (HT) Heat which is not affordable by HP maintaining their Coefficient of Performance. To face this issue, RES can be used to produce synthetic fuels for feeding existing energy systems, the so-called Power-to-Gas option. In this way, greening the fuel supply can be seen as the best option for meeting HT heating demand while, Medium and Low Temperature are met by HP. Therefore, two technological scenarios, P2H and its combination with P2G, are presented and assessed in three reference Urban Energy Systems. The authors investigated on the impact of RES share increase from 25% up to 50% in the electricity mix with the objective function of Primary Energy Consumption (PEC). The outcomes of twenty-four energy scenarios, eight for each Reference City were assessed also through the value of delivered Renewable Heat. Finally, the leverage effect of P2G on the system is evaluated in terms of renewable heat contribution.     

Residential energy use: Analysis of disaggregate data

The Energy Information Administration recently published data they collected from the National Interim Energy Consumption Survey (NIECS). NIECS includes detailed information on 4081 individual households: demographic characteristics, energy-related features of the structure, heating equipment and appliances therein, recent conservation actions taken by the household, and fuel consumption and costs for the April 1978–March 1979 one-year period. This data set provides a new and valuable resource for analysis. We summarized and analysed the NIECS data on household energy consumption — total energy use, electricity use, and use of the primary space heating fuel. The regression equations constructed explain roughly half the variation in energy use among households. These equations contain 10 or fewer independent variables, the most important of which are fuel price, year house was built, floor area, and heating degree days.     

Development of a software package for community energy system assessment – Part I: Building a load estimator

As part of an assessment software package for community energy systems, a database application is developed to systematically calculate the energy demands for mixes of 12 different types of building in Korea. The program generates the hourly demands for electricity, heating, cooling, and hot water for the mix of building types for 8760 h of a year. The calculation is based on field and measured data from major cities throughout the country. The energy demand curves generated by the package can be applied to the basic design processes of CESs (Community Energy Systems).     

Effects of demand side management on Chinese household electricity consumption: Empirical findings from Chinese household survey

China’s residential electricity demand has grown rapidly over the last three decades and given the expected continued growth, demand side management (DSM) can play an important role in reducing electricity demand. By using micro-level data collected from 1450 households in 27 provinces in the first-ever China Residential Energy Consumption Survey in 2012, this study estimates the effects of three DSM measures empirically: tiered household electricity pricing, China Energy Label program, and information feedback mechanisms. We find these measures have contributed to moderating residential electricity demand growth but additional policy reform and tools are needed to increase their effectiveness and impact. Residential electricity demand is found to be price- and income- inelastic and tiered pricing alone may not be as effective in electricity conservation. The statistically significant relationship between China Energy Label efficient refrigerators - but not televisions - and lowered residential electricity consumption reflect mixed program effectiveness. Lastly, of the information feedback currently available through electricity bills, payment frequency and meters, only meter reader is estimated to be statistically significant. Important policy implications and recommendations for improving each of these three DSM measures to expand their impact on reducing residential electricity consumption are identified.