Method for rating energy performance of public buildings

This paper discussed a comparative study of several state-of-art methods for determining building energy consumption benchmark. A new approach, which combined the idea of “building benchmark” and “operational benchmark” in its rating system, was proposed. A case study was conducted which applied the proposed approach to benchmarking an existing office building in Tianjin. Besides, the calculation of benchmarks of the reference building model and real building model using the rating method in eQUEST was also considered. Furthermore, the simulation results of the reference building model were taken as the baseline to divide real office buildings into different energy performance grades.     

Public energy performance policy and the effect on diffusion of solar thermal systems in buildings: A Dutch experience

Energy performance policy is an important element in the European Energy Performance of Buildings Directive (Directive 2002/91/EC—in short: EPBD, published 4 January 2003), which the European Commission is now urging all European member states to introduce for the building sector by 2006. One of the expected benefits of energy performance policy is that it can help to introduce innovations such as solar thermal systems. However, few studies have analysed this so far. This paper describes the extent to which the penetration of solar thermal systems in the residential building sector is directly related to energy performance policy in the Netherlands. The concept of energy performance policy is explained and the effects of using energy performance policy for several years in the Netherlands are described, through the results of an empirical study. Statistical analysis appears to show no association between Dutch energy performance policy and the application of solar thermal systems in the domestic sector.     

美绿色建筑节水评价标准对比分析

绿色建筑是指在建筑的全寿命周期内,最大限度地节约资源,包括节能、节地、节水、节材、保护环境和减少污染,为人们提供健康、适用和高效的使用空间,与自然和谐共存的建筑.基于可持续发展指导原则,许多国家都编制了可用于指导绿色建筑的原则和适宜标准.在简述中美绿色建筑评价标准的基础上,分析我国绿色建筑评价标准和美国LEED-NC标...     

Reducing energy use in the buildings sector: measures, costs, and examples

This paper reviews the literature concerning the energy savings that can be achieved through optimized building shape and form, improved building envelopes, improved efficiencies of individual energy-using devices, alternative energy using systems in buildings, and through enlightened occupant behavior and operation of building systems. Cost information is also provided. Both new buildings and retrofits are discussed. Energy-relevant characteristics of the building envelope include window-to-wall ratios, insulation levels of the walls and roof, thermal resistance and solar heat gain coefficient of windows, degree of air tightness to prevent unwanted exchange of air between the inside and outside, and presence or absence of operable windows that connect to pathways for passive ventilation. Provision of a high-performance envelope is the single most important factor in the design of low-energy buildings, not only because it reduces the heating and cooling loads that the mechanical system must satisfy but also because it permits alternative (and low-energy) systems for meeting the reduced loads. In many cases, equipment with significantly greater efficiency than is currently used is available. However, the savings available through better and alternative energy-using systems (such as alternative heating, ventilation, cooling, and lighting systems) are generally much larger than the savings that can be achieved by using more efficient devices (such as boilers, fans, chillers, and lamps). Because improved building envelopes and improved building systems reduce the need for mechanical heating and cooling equipment, buildings with dramatically lower energy use (50–75% savings) often entail no greater construction cost than conventional design while yielding significant annual energy-cost savings.

U.S. state policies for renewable energy: Context and effectiveness

Over the past decade, state policies on renewable energy have been on the rise in the U.S., providing states with various options for encouraging the generation of renewable electricity. Two promising policies, the Renewable Portfolio Standard (RPS) and the Mandatory Green Power Option (MGPO), have been implemented in many states but the evidence about their effectiveness is mixed. In this paper, we argue that recognizing the natural, social, and policy context under which MGPO and RPS are adopted is necessary in order to measure their true effectiveness. This is because the context rather than the policy might lead to positive outcomes and there is the possibility for sample bias. When controlling for the context in which the policies are implemented, we find that RPS has a negative impact on investments in renewable capacity. However, we find that investor-owned utilities seem to respond more positively to RPS mandates than publicly owned utilities. By contrast, MGPO appears to have a significant effect on installed renewable capacity for all utilities regardless of the context in which it is implemented.     

Design and assessment of a solar energy based integrated system with hydrogen production and storage for sustainable buildings

The current study investigates a holistically developed solar energy system combined with a ground-sourced heat pump system for stand-alone usage to produce power, heat, and cooling along with domestic hot water for residential buildings. An integrated system is proposed where three types of building-integrated photovoltaic plant orientation are considered and integrated with a vertical-oriented ground-sourced heat pump system as well as an anion exchange membrane electrolyser for hydrogen-based energy storage along with proton exchange membrane fuel cells. The ground-sourced heat pump system covers the heating requirements and exploits the available thermal energy under the ground. Hydrogen subsystem enables the integrated system to be used anytime by compensating the peak periods with stored hydrogen via fuel cell and exploiting the excess energy to produce hydrogen via electrolyser. The photovoltaic plant orientations are extensively designed by considering geometries of three different applications, namely, rooftop photovoltaic, building-integrated photovoltaic façade and photovoltaic canopy. The shading and geometrical losses of photovoltaic applications are extensively identified and considered. In addition, the openly available high-rise building load profiles are obtained from the OpenEI network and are modified accordingly to utilize in the current study. The building requirements are considered for 8760 h annually with meteorological data and energy usage characteristics of the selected regions. The integrated system is assessed via thermodynamic-based approach from energy and exergy points of views. In order to increase generality, the proposed building energy system is analyzed for five different cities around the globe. The obtained results show that a 20-floor building with approximately 62,680 m² residential area needs between 550 kWp and 1550 kWp of a photovoltaic plant in five different cities. For Ottawa, Canada, the overall energy and exergy efficiencies are found as 18.76% and 10.49%, respectively, in a typical meteorological year. For the city of Istanbul in Turkey, a 20-floor building is found to be self-sufficient by only using the building's surface area with a 495 kWp BIPV façade and a 90 kWp rooftop PV.     

Long-term energy projections for the U.S.A.

This report starts by surveying a series of papers that are representative of recent U.S. work on national and international energy policy. Among professional analysts, there are the beginnings of a consensus on energy demand projections and on energy-economy interactions. Moreover, it is recognized that conservation policies will be difficult to implement unless domestic prices are raised to the international level. The paper includes a series of long-term energy projections based upon ETA-MACRO. This model allows for: energy-economy interactions, cost-effective conservation and interfuel substitution between electric and nonelectric energy. the calculations are based upon a somewhat less optimistic view of synthetic fuels and of ‘backstop’ technologies than appear in the Carter Administration's recent proposals. With synfuels, backstops and nuclear energy—and with realistically reduced projections of demand growth—there is a reasonable prospect that the U.S. could meet an international commitment to limit oil and gas imports. U.S. import reductions could be achieved directly through the market price mechanism, without tariffs or quota limitations. For this to happen, however, the international price of oil would have to be doubled (in constant dollar terms) by the year 2000. A policy of gradual OPEC oil price increases would facilitate the transition away from oil, and could serve the long-run interests of both the producing and consuming nations.     

Future U.S. energy technologies: Cost and oil-import tradeoffs

Many new energy technologies offer the potential of moderating the rising costs of energy while, at the same time, reducing dependence on imported oil. The problem of evaluating which technologies offer the most promise is complex and requires analyzing competition in the marketplace among new and existing technologies over a long span of time. This competition would occur under a variety of future situations affecting energy resources, costs, and technology availability. With the aid of a linear-programming model, we have conducted such an evaluation. The results indicate that the most promising technologies include the light-water reactor, residential and commercial conservation, enhanced oil recovery, shale-oil recovery, industrial cogeneration, the heat pump, and coal liquefaction. This usage yields a decline in oil imports to about half present levels, exactly when depending upon the situation. These results need to be evaluated in light of environmental and other effects not included in the model.     

Low exergy (LowEx) heating and cooling systems for sustainable buildings and societies

Heating, cooling and lighting appliances in buildings account for more than one third of the world's primary energy demand and there are great potentials, which can be obtained through better applications of the energy use in buildings. In this regard, the building sector has a high potential for improving the quality match between energy supply and demand because high temperature sources are used to meet low-temperature heating needs. Low exergy (or LowEx) systems are defined as heating or cooling systems that allow the use of low valued energy, which is delivered by sustainable energy sources (i.e., through heat pumps, solar collectors, either separate or linked to waste heat, energy storage) as the energy source. These systems practically provide heating and cooling energy at a temperature close to room temperature while the so-called LowEx approach, which has been and still being successfully used in sustainable buildings design.The present study comprehensively reviews the studies conducted on LowEx heating and cooling systems for establishing the sustainable buildings. In this context, an introductory information is given first. Next, energy utilization and demand in buildings are summarized while various exergy definitions and sustainability aspects along with dead (reference) state are described. LowEx heating and cooling systems are then introduced. After that, LowEx relations used to estimate energy and exergy demand in buildings and key parameters for performance assessment and comparison purposes are presented. Finally, LowEx studies and applications conducted are reviewed while the last section concludes. The exergy efficiency values of the LowEx heating and cooling systems for buildings are obtained to range from 0.40% to 25.3% while those for greenhouses vary between 0.11% and 11.5%. The majority of analyses and assessments of LowEx systems are based on heating of buildings.     

U.S. federal government subsidies for clean energy: Design choices and implications

Subsidies for clean energy deployment have become a major component of U.S. federal energy and climate policy. After a surge in spending under the American Recovery and Reinvestment Act of 2009, they are an even larger component but now face increased scrutiny. Given their lasting presence, how does one design these subsidies to be as cost-effective as possible? Surprisingly, the conceptual framework and empirical evidence available to help policymakers identify which subsidies generate the most “bang for the buck” are limited. To help answer this question, we begin with an overview of the justifications for, and the arguments against, subsidizing clean energy technologies. Next, we briefly describe major subsidies. Finally, we summarize key design choices, suggesting an increased focus on upfront cash payments for physical outcomes such as capacity. This contrasts with the considerable focus on tax credits, loan guarantees, production, and cost-based subsidies which have been more prominent to date.     

U.S. Disaggregated renewable energy consumption: Persistence and long memory behavior

This study examines the degree of time persistence in U.S. disaggregated renewable energy consumption (hydropower, geothermal, solar, wind, wood, waste, and biofuels) using innovative fractional integration and autoregressive models with monthly data for the period 1994:2 to 2011:10. The results indicate that in the case of hydropower, solar, wind, waste, and biofuels the estimates of fractional integration are higher than 0.5 but less than 1.0 implying nonstationary, but mean reverting behavior. In the case of geothermal and waste the estimates of fractional integration are around 0.5 and in the boundary case between stationarity and nonstationarity. For wood, the estimate of fractional integration is significantly smaller than 0.5 and thus showing stationary behavior with long memory behavior. Furthermore, the study incorporates the presence of breaks in the data with the absence of breaks in hydropower, geothermal, solar, wind, wood, and biofuels, but a single break in the case of waste due to the inclusion of non-renewable waste from non-biogenic sources through 2000. The results reveal that U.S. disaggregated renewable energy consumption measures are better explained in terms of a long memory model that incorporates persistence components and seasonality.     

Renewable energy consumption and industrial production: A disaggregated time-frequency analysis for the U.S.

This paper aims to analyze the interaction between renewable energy consumption and industrial production for the U.S. over the 1981–2018 period. We contribute to the existing literature by the disaggregation of renewable energy sources (hydropower, geothermal, and biomass), by the consideration of time and frequency through wavelet techniques and the time-varying Granger causality test recently proposed by Shi et al. (2018). Based on monthly data, wavelet results show a positive co-movement between industrial production and biomass energy consumption at low frequencies, meaning in the long term only. The bootstrap rolling-window Granger causality test indicates a bi-directional predictability between renewable energy consumption and industrial production in crisis and turmoil periods only. These results are found to be robust to the inclusion of control variables (non-renewable energy consumption and crude oil prices) and to the selection of the lag length for the corresponding VAR model.     

A novel method for the design of CHCP (combined heat,cooling and power) systems for buildings

The design of capacity and operation of CHCP (combined heat, cooling and power) plants applied to HVAC (heating, ventilation and air conditioning) in buildings entails a considerable difficulty, because efficiency and economic aspects frequently interact in a complex way. Due to the strong fluctuations in thermal demands, the evaluation of a given design usually requires detailed simulations and a significant amount of input data. This paper proposes simplified approaches to estimate the main parameters characterising the thermal performance of the plant (ATD_e method) as well as to identify optimal designs for a given application under certain encouragement policies (annual PES (primary energy savings) strategy). In the ATD_e method, the duration curve of ATD (aggregated thermal demand) is used to estimate, among others, the amount of heat and cooling effectively supplied to the final user for a given design of the plant. This procedure serves to achieve a quick, global evaluation of the thermal performance of CHP (combined heat and power) or CHCP plants with little computational effort. The annual PES strategy searches the optimal values for the engine capacity, the OP (operation period) or both for CHP and CHCP plants in a particular application, defined by its energy demands. Both methods have demonstrated a notably good performance in several test cases with different patterns of the thermal demands.     

Modeling and forecasting the U.S. manufacturing aggregate energy intensity

Two forecasting models are developed for forecasting the U.S. manufacturing aggregate fuel and electricity intensities. The models are both simple to apply and capable of identifying the effect of underlying forces of aggregate energy intensity change. The validation of the results provided by these models is performed by comparing these results with those rendered by conventional decomposition techniques based on economic index numbers. The results indicate that the aggregate fuel intensity is expected to decline by 3.2%yr^?1 from the year 2000 to 2010, of which 1.1%yr^?1 is due to structural effect, i.e. a share of 32.9% of aggregate fuel intensity change. The results also show that in the same period the aggregate electricity intensity is expected to decline at a rate of 1.2%yr^?1, of which 0.6%yr^?1 is due to structural effect, i.e. a share of 46.3% of aggregate electricity intensity change. Copyright © 2007 John Wiley & Sons, Ltd.     

Evaluation on energy and thermal performance for residential envelopes in hot summer and cold winter zone of China

As a result of rapid economic growth in the last several decades, energy issue is becoming more and more important in today’s world because of a possible energy shortage in the future; the usage of residential electricity has increased rapidly in China and building energy efficiency is included as one of the 10 key programs targeting energy efficiency improvement in the 11th Five-Year Plan. In response to the growing concerns about energy conservation in residential buildings and its implications for the environment, systematic evaluation on energy and thermal Performance for residential envelops (EETP) is put forward to assess the energy efficiency of envelop designs and to calculate the energy consumption of cooling and heating systems. Hot summer and cold winter zone of China was selected for EETP analysis because of its rigorous climatic and huge energy consumption. The correlations between EETPs and electricity consumptions in cooling season, heating season, and the whole year were built in Shanghai, Changsha, Shaoguan and Chengdu, which represent A, B, C and D subzone of hot summer and cold winter zone in China, respectively. Illustrations indicate that the algorithm is simple and effective, energy and thermal performance of residential envelopes can be evaluated easily. The maximum allowable values of EETPs were determined when just meeting the compulsory indices of Standard JGJ134-2001, the corresponding allowable EETPs were also gained when achieving different energy-saving degrees on basis of it. EETP method can suggest possible ways to improve the energy efficiency for envelope designs of new building and retrofits of existing buildings and provide governments some useful information for the establishment of new policy on energy efficiency buildings. It has important meanings to carry out sustainable residential building designs with high thermal comfort and low energy consumption.     

Energy-efficiency supervision systems for energy management in large public buildings: Necessary choice for China

Buildings are important contributors to total energy consumption accounting for around 30% of all energy consumed in China. Of this, around two-fifths are consumed within urban homes, one-fifth within public buildings, and two-fifths within rural area. Government office buildings and large-scale public buildings are the dominant energy consumers in cities but their consumption can be largely cut back through improving efficiency. At present, energy management in the large public sector is a particular priority in China. Firstly, this paper discusses how the large public building is defined, and then energy performance in large public buildings is studied. The paper also describes barriers to improving energy efficiency of large public buildings in China and examines the energy-efficiency policies and programs adopted in United States and European Union. The energy-efficiency supervision (EES) systems developed to improve operation and maintenance practices and promote energy efficiency in large public sector are described. The benefits of the EES systems are finally summarized.     

Direct and indirect energy use and carbon emissions in the production phase of buildings: An input–output analysis

There is a considerable disagreement in the literature on the magnitude of primary energy use and CO₂ emissions linked to the production of buildings. In this paper we assess the Swedish building sector using top-down input–output analysis. These top-down results are then disaggregated into sectors and activities, which are compared to results from 18 previous bottom-up studies using process-LCA methodology. The analysis shows almost 90% higher specific energy use (GJ/m²) for the top-down methodology. The differences are only around 20% for the share coupled to production and processing of building materials, while for other involved sectors such as transport, construction activities, production of machines and service sectors, the input–output analysis gives much higher values. Some of these differences can be explained by truncation errors due to the definition of system boundaries in the bottom-up studies. The apparent underestimation of energy use for transport, services etc. in bottom-up studies is only of marginal importance when comparing for example materials choices, but when comparing the production phase to the use phase of buildings such errors are likely to result in an underestimation of the relative importance of the production phase since the use phase is dominated by more easily estimated direct energy use.     

Causality between energy consumption and GDP in the U.S.: evidence from wavelet analysis

This study investigates the dynamic causal relationship between energy consumption and economic growth in the U.S. at different time scales. The main novelty of the study is that this paper complements the existing studies on the nexus between energy consumption and economic growth by employing the wavelet transformation to obtain different time scales in order to investigate causality between energy consumption and economic growth. This method is first developed by Ramsey and Lampart. Their approach consists of first decomposing the series into time scales by wavelet filters and testing causality of each time scale with the pertinent time scale of the other series separately. The data span from 1973q1 to 2012q1 on a quarterly basis. The main empirical insight is that the causal relationship is stronger at finer time scales, whereas the relationship is less and less apparent at longer time horizons. The results indicate that energy consumption causes economic growth, while the reverse is not true at the original frequency of the data. At the very finest scale the same result arises. However, at coarser scales feedback is observed. In particular, at intermediate time scales the evidence indicates that energy consumption causes economic growth, while the reverse is also true. These empirical findings are expected to be of high importance in terms of the effective design and implementation of energy and environmental policies, especially when a number of countries in the pursuit of high economic growth targets do not pay any serious attention on environmental issues.     

Dynamic characteristics and energy performance of buildings using phase change materials: A review

Thermal energy storage (TES) systems using phase change material (PCM) have been recognized as one of advanced energy technologies in enhancing energy efficiency and sustainability of buildings. The use of PCMs in buildings provides the potential for a better indoor thermal comfort for occupants due to the reduced indoor temperature fluctuations, and lower global energy consumption due to the load reduction/shifting. A good knowledge on dynamic characteristics and energy performance of buildings using PCMs is essential for building researchers and practitioners to better understand building temperature response characteristics and economic feasibility of using PCMs and take further proper actions to fully utilize PCMs to enhance indoor environmental quality and overall energy efficiency of buildings. This paper presents an overview of the previous research work on dynamic characteristics and energy performance of buildings due to the integration of PCMs. The research work on dynamic characteristics and energy performance of active and passive building applications is reviewed, respectively. Since the particular interest in using PCMs for free cooling and peak load shifting, the specific research efforts on both subjects are reviewed separately. A few useful conclusive remarks and recommendations for future work are presented.