bluuebunny/crossref_metadata_2025 huggingface dataset:
Compression Ignition Engines: State‐of‐the‐Art and Current Technologies. Future Trends and Developments
Authors: Payri Francisco , Desantes José‐María , Benajes Jesús
Published: July 2015

This article presents the basic operation characteristics of compression‐ignition (CI) or diesel engines, focusing on those features that are distinctive of these powerplants. Therefore, the focus has been placed on the thermofludynamic phenomena related to air management, injection, and combustion. Moreover, in every section, after presenting the basics, the most important expected technologies and strategies for future improvements are commented. Care has been taken for not repeating information that is contained in other article of the manual.

First, the main characteristics, advantages, and challenges of theCIengine are discussed, often in contrast with the alternativeSIengine. Then, the main features of the injection combustion and pollutant formation processes are exposed. Even though these processes are completely interrelated and occur partially simultaneously at the same time, an effort has been made to separate their individual aspects in every section. Following, some sections are devoted to the air management requirements such as turbocharging, exhaust gas recirculation, and variable valve timing.
Geothermal Power Generation
Authors: Eghbal Mehdi
Published: July 2015

Geothermal energy is the heat energy generated from radioactive decay of minerals and stored in the Earth. Theoretically, total geothermal resources are more than adequate to supply all human energy needs for many years. However, so far only a small portion of geothermal energy has been extracted and used either directly as a heat source or converted to electricity. Often significant drilling and exploitation costs make the energy conversion process unfeasible.

Geothermal industry has been significantly developed since the first commercial geothermal plant was built in 1904 in Italy. Geothermal sources are in different forms including dry hot steam, hot water, and hot rock. Depending on the characteristics of each geothermal resource, different types of geothermal plants have been designed and installed. Single‐ or double‐flash power plants are the most common plants for hot water geothermal resources.

As the technology develops and more renewable energy policies are introduced, the levelized cost of geothermal power decreases. Future technology developments, renewable energy initiatives, and availability of other sources of energy are expected to further reduce the cost of geothermal power.

This article provides an overview of geothermal history and focuses on reviewing the principles of geothermal energy conversion systems. Some statistics of major past and current geothermal power plants are given; however, as new geothermal power plants become online in future, care should be taken when referring to these statistics.
Grid Connection and Power Conditioning of Wind Farms
Authors: Singh Mohit , Allen Alicia , Hodge Bri‐Mathias S.
Published: July 2015

Wind power penetrations are increasing worldwide, and with these increasing penetrations come increasing worries about their impact on power systems operations. Wind interconnection studies are a very important step for maintaining grid reliability, stability, and power quality. The behavior of a wind plant during dynamic events is an important consideration in that it can impact the rest of the system, potentially compounding contingency event impacts with a suboptimal response. The response of a wind turbine to such an event is strongly influenced by the generator type, and each turbine type has different requirements in terms of low voltage ride through, reactive power requirements, and frequency control. Additional measures may also be taken to protect the generator in the case of an event, while still providing necessary services to the grid.
Energy Efficiency Index via Data Envelopment Analysis (
DEA
): Methodology and Application
Authors: Wang Ke
Published: July 2015

Data envelopment analysis (
DEA
) has recently become a popular approach in measuring the regional energy and environmental efficiency at the macroeconomy level. Within a joint production framework of considering both desirable and undesirable outputs, as well as the separation of energy inputs and nonenergy inputs, this study proposes several energy efficiency indices based on (i) the traditional
DEA
with undesirable outputs transformation technique; (ii) the directional distance function‐based
DEA
relying on the weak disposability assumption; (iii) the range adjusted measure‐based method relying on the natural and managerial disposability assumptions; and (iv) the multidirectional efficiency analysis approach from which both the energy efficiency status and the energy efficiency patterns of different regions can be detected. The characteristics of the above
DEA
‐based energy efficiency indices will be further compared and discussed, and these methods and related indices are applied to regional energy and environmental efficiency evaluation of clean energy system.
Diagnostic and Control of Energy Systems in Power Generation Systems and Process Industries
Authors: Dahlquist Erik , Avelin Anders
Published: July 2015

A lot of efforts are normally done to design plants in an efficient way. Still, most plants are having varying production qualities and quantities and both the diagnostics of sensors and process performance and advanced control for optimal production are essential. Useful methods and applications of these for both power plant and process industry applications are presented. The benefits of using, for example, simulators are described in connection with start‐up of new plants and the importance of diagnostics for maintenance of demand. Examples are shown where statistical methods are used to predict pulp paper quality properties and physical models to perform data reconciliation and decision support. The data reconciliation predicts true values for sensors that are drifting while decision support is giving advice when any kind of possible problem has been detected. In addition, process optimization and model‐based control are discussed.
Efficient Residential Indoor Thermal Environment Control
Authors: Deng Shiming , Li Ning
Published: July 2015

In this article, recent developments on the efficient control of residential indoor thermal environment are reported. Firstly, fundamental issues for indoor environmental control in residences are discussed. This is followed by presenting an analysis of a number of current control issues for direct expansion (
DX
) air‐conditioning (A/C) systems, including the capacity control, humidity control, and the inherent operating characteristics of a
DX
A/C system. A number of studied efficient control strategies for simultaneous controlling indoor air temperature and humidity using a
DX
A/C system, including direct digital control (
DDC
)‐based control, multi‐input multi‐output (
MIMO
) control, and artificial neural network (
ANN
)‐based control, are reported subsequently. Finally, some other related issues on residential indoor thermal environmental control using
DX
A/C systems, including a novel indoor humidity control algorithm (H–L (high–low) control algorithm), capacity control of multi‐evaporator air‐conditioning (
MEAC
) systems, and A/C for sleeping environments in the tropics and subtropics are discussed. It is expected that with the improvement on indoor thermal environmental control in residences, occupants' thermal comfort can be improved and more importantly, the energy use for A/C residential buildings reduced. This would in turn help reduce energy consumption in buildings, and thus carbon emission, contributing to sustainable development.
An Institutional Perspective on the Low Carbon Transition
Authors: Andrews‐Speed Philip
Published: July 2015

The transition to a low carbon economy requires a change of sociotechnical regime or, in other words, a change in the way that society and technology interact. This, in turn, entails changes in economic, political, and societal institutions, the terminstitutionsreferring to the formal and informal rules and the expectations that govern the behavior of actors in a society. Tangible factors such as the availability of technology and skills and the endowment of resources and infrastructure provide significant constraints to countries seeking to undertake the transition to a low carbon economy. However, institutions also play a strong role in constraining the rate and shaping the path to a low carbon economy. As each nation is characterized by different institutions, the nature of the low carbon transition will vary from country to country, and even within individual countries. This article explains the relevance of institutions to the low carbon transition and applies this understanding to China and the United Kingdom in order to examine how different types of institution shape the way in which energy is governed, with particular reference to the consequences for the deployment of renewable energy.
Load Control and Management of Systems with Thermal Power, Hydro Power, and Wind
Authors: Söder Lennart
Published: July 2015

This article has the goal to provide an overview about the challenges that one may face with the integration of large‐scale wind and solar power into a hydro‐thermal power system. The aim is to provide an overview of the challenges in order to identify the most important issues. The goal is to provide a general presentation, but some descriptions are mainly relevant for systems with larger share of hydro power. The article is focused on the balancing issues, that is, how to keep the production‐consumption balance in an efficient way also in a system with larger amounts of wind and solar power. The focus is on the continuous balancing, with the two special cases of low wind+solar and high wind+solar situations. For a successful integration all situations have to be handled in a technical/economical efficient way.
Overview of Wind Energy Resource
Authors: Kaldellis John K.
Published: July 2015

An overview of wind resource characteristics is presently undertaken, with emphasis given on the way these characteristics influence the energy performance of contemporary wind turbines. To this end, the main characteristics of wind speed patterns, represented by the scale and shape parameters of Weibull distribution, are first studied, with the effectiveness of established theoretical distributions to describe wind regimes being accordingly evaluated. Next, special attention is given to calm spells and their significance in the design of stand‐alone wind‐based installations. Frequency and intensity of wind gusts causing fatigue of wind turbines through increased loading are next investigated, followed by the study of wind shear and its implications on the wind energy yield. Finally, air density variation and the wake effect are considered, again in relation to their influence on the energy performance of contemporary wind turbines.
Modeling Energy Efficiency and

CO
2

Emissions Reduction
Authors: Miglio Rocco De , Gargiulo Maurizio , Chiodi Alessandro , Deane Paul , Gallachóir Brian Ó
Published: July 2015

Energy efficiency and

CO
2

reduction are key concepts in defining sustainability worldwide. At the European level, for example, a binding legislation, known as
20‐20‐20 climate and energy package
, sets three objectives for 2020 among which, explicitly, the 20% improvement of energy efficiency and the cut of 20% in greenhouse gas (GHG) emissions from 1990 levels are the most important objectives. It is generally accepted that a relationship between these two variables exists, but what is the contribution of energy efficiency to

CO
2

emissions reduction? Improving or increasing energy efficiency however does not always translate into reduced

CO
2

emissions; the savings depend on the situation and the energy system. If the energy is supplied from fossil fuels—such as electricity from a coal‐fueled plant—then improved efficiency will cut emissions. However, if the energy is supplied by a low carbon source such as electricity from low carbon renewables, then improving efficiency may have a limited impact on overall emissions reduction. An energy systems model is a suitable tool to allow decision makers to estimate the effects of comprehensive, as well as sectoral‐specific, commitments and measures in the medium–long term, and may also be seen as a useful platform for testing different policies, supporting the comparative assessment of energy and environmental performances in the system under investigation.
Bioenergy Potential from Forest Biomass
Authors: Leduc Sylvain , Kindermann Georg , Forsell Nicklas , Kraxner Florian
Published: July 2015

Forestry‐based biomass has become a valuable resource for mitigating emissions and conversion production of bioenergy. It can be converted into heat, power, and advanced transport fuel. It has been a major fuel for household heating, but its industrial use for heat and power has been increasing in forest‐rich countries such as Scandinavia or Austria. It has the advantage of not competing for the land for food crop resources and has lower end‐use emissions compared to conventional energy feedstock. Moreover, due to the mandatory energy targets set by each country in the European Union (
EU
), the use of woody biomass is expected to increase and play a major role in the share of the energy fuel mix. This article presents the forest potential dedicated for bioenergy for the
EU
based on the linkage between a forest and a techno‐economic model.
The Revealed Relationships between Energy Consumption and Economic Growth: Causality, Macroeconomics, New Trend, and Implications
Authors: Chang Youngho , Li Yanfei
Published: July 2015

The literature of the “energy–economy” relationship presents mixed conclusions. Such conclusions could attribute mainly to the differences in methodology (econometrics), the selection of the data (period, frequency, length, time series vs panel data), the variety of possible explanatory variables employed in the model, different dynamics (lag structure) modeled, heterogeneity in the behavior of different sectors in the economy, heterogeneity in climate conditions, and various levels of development and economic structure. Even for the same countries, as its economy develops and its structure changes, the short‐run and long‐run relationships between energy consumption and economic growth may also change.

This article reviews the literature on the “energy–economy” relationship and presents the evidence from studies that apply various methodologies and raise the research question at different levels of details and with different perspectives. It presents the relationships in four distinct hypotheses: a unidirectional causality from economic growth to energy consumption, a unidirectional causality from energy consumption to economic growth, a bidirectional feedback between energy consumption and economic growth, and no relationship at all (i.e., the neutrality hypothesis). This article also dives into the role played by other macroeconomic factors such as population, capital stock, prices, and technologies in revealing the true relationship between energy consumption and economic growth. The literature has started to pay more attention to sectoral characteristics of energy consumption and economic growth as well as the characteristics of different types of energy such as oil, natural gas, coal, nuclear, and renewable energy. These factors could reveal the new details of the hypotheses that drive a causality in either direction. Finally, this article presents relevant policy implications derived from the revealed relationships.
Polygeneration Microgrids for Residential Applications
Authors: Kyriakarakos George , Papadakis George
Published: July 2015

Considerable research is taking place globally concerning the energy consumption in residential buildings. The effort is aimed toward the creation of zero energy buildings or even positive energy ones. In order to accomplish this, energy production is needed at the building level. Electrical energy, thermal energy for space heating and cooling, and domestic hot water production are common needs globally, whereas water pumping, water desalination, and onsite fuel production are also of rising interest. The polygeneration microgrid topology aims at unifying all the energy systems in a building and through advanced energy management approaches to optimize the energy flows in the building managing to provide optimum indoor comfort, meeting of all the energy needs of the residents and minimizing the environmental impact of the building. This article presents this topology in detail and also proposes a methodology for the design and sizing of such systems.
Introduction: Sustainability of Energy Systems
Authors: Chou S. K. , Wei Yi‐Ming , Yan Jinyue
Published: July 2015

Over the decade, sustainable low carbon future has become the focus for contemporary policy discussions. The path toward decoupling economic growth with energy, especially fossil energy is a challenging one. It requires top‐down, coordinated effort among public institutions to establish a supportive policy and political environment; and bottom‐up, the deployment of technological measures through efficient financing instruments. Recent years have seen an increasing use of the integrated energy‐economic‐environment modeling framework for facilitating the decision‐making process. These include the macroeconomic modeling framework, the process‐driven modeling framework, and a combination of both frameworks. While the energy analysis and modeling tools are useful in understanding the evolution of the energy systems, the global energy policy and geopolitics are receiving more and more influence from the development of unconventional resources. Essentially, it is uncertain what the future of the global and regional dynamics could evolve as more unconventional resources become recoverable outside the oil exporting economies. Nonetheless, sustainable development toward a low carbon future cannot be achieved by an individual country. Moving forward, it requires transnational cooperation beyond Kyoto Protocol and climate change negotiations if, indeed, nations worldwide are serious about making the Earth a better living place.
Between Climate Change and Energy Security Objectives: The Potential Role of Shale Gas
Authors: Gracceva Francesco , Zeniewski Peter
Published: July 2015

The increasing interest in developing unconventional hydrocarbon resources will have important interactions with the transition to a low carbon energy system. The purpose of this article is to explore the uncertainty around the future development of shale gas and to study the complex relationship between climate change policies and energy security, using a methodology accounting for the multidimensional and systemic nature of energy security. Using a complex multiregional model of the global energy system, a scenario analysis has been developed to answer two questions: (i) to what extent and under which conditions is the deployment of shale gas consistent with a low carbon system? (ii) as a low carbon energy system prompts a number of structural changes along the whole energy supply chain, can shale gas help to dampen the negative impact on energy security of these changes? The structure of this article is as follows. Section 1 will conceptualize the links between energy security and low carbon policies and will introduce a methodological framework to assess their interactions. Section 2 will outline the modeling tools used for this assessment, and will elaborate on the input assumptions guiding the scenario analysis. Section 3 will present the results and discuss them in the context of the methodological framework set out in the first section. This will be followed by a conclusion and recommendation for future research.
Compact Heat Exchangers in Clean Energy Systems
Authors: Tu Shan‐Tung , Zhou Guo‐Yan
Published: July 2015

With the increase of awareness of energy shortage, saving energy and reducing environment pollution have become the major principle of industrial production. Developing more sustainable energy systems is perhaps the most critical issue that today's society must address. During the development of the new generation of energy systems, such as aero engine, and nuclear power system, it is found that applying compact heat exchangers (CHEs) considerably increases the efficiency of the systems. This article provides a brief introduction ofCHEsused in clean energy systems. The structures of theCHEsare illustrated, and their heat transfer enhancement mechanisms and their advantages and limitations are summarized. Moreover, the design methodology, heat transfer, and friction correlations for four types of CHEs are provided in detail.CHEstechnologies are expected to play an even more important role in the cleaner energy systems.
Mobilized Thermal Energy Storage (M‐TES) Technology for Industry Heat Recovery
Authors: Wang Weilong , Yan Jinyue
Published: July 2015

A new so‐called mobilized thermal energy storage (M‐TES) system for the recovery of industrial waste heat for supplying heat for distributed users, for example, detached houses or other applications is presented. The M‐TESis a technology that uses the thermal energy storage materials, often phase‐change materials (PCMs), to store waste heat and then transport the stored energy to another location for releasing heat for distributed users. The advantages of this system will enable the efficient use of waste heat in an economically variable way to deliver heat without pipeline as normally done in a district heat network. Experimental tests of different storage materials and the dimension and structure of the storage tank and heat exchangers in the M‐TESare presented in this article. Feasibility study to identify the economic and energy benefits of the M‐TESof some industrial cases has also been performed. This article provides optimized materials and system design for distributed users.
Hydrogen Energy Storage Systems for Grid and Community Applications
Authors: Melaina Marc W. , Steward Darlene , Eichman Joshua , Zuboy Jarett
Published: July 2015

Hydrogen energy storage systems can provide multiple energy services, including bulk storage for grid support, ancillary services, and distributed energy storage for vehicle refueling or other end uses. Each of these services is reviewed in this article, drawing upon a variety of studies to characterize or quantify each service. The distributed storage discussion elaborates on a case study of distributedPV‐connected distributed storage to supply hydrogen to fuel cell electric vehicles (FCEVs). Cost estimates consider hourly and seasonal prices and demand fluctuations and draw comparisons to distributedPVelectricity supply for battery electric vehicles (BEVs). The analysis suggests that distributed hydrogen storage systems can be economically competitive with battery electricity storage for vehicles at larger scales.
Biomass Gasification and Pyrolysis
Authors: Adhikari Sushil , Adoulmoumine Nourredine
Published: July 2015

This article discusses fundamentals of gasification and pyrolysis and associated technologies in detail. Also discussed are challenges and solutions pertaining to syngas cleanup, bio‐oil upgrading, and product utilization for gasification and combustion.
Environmental Life Cycle Assessment (LCA) of Energy Systems
Authors: Hammond Geoffrey P. , Jones Craig I. , O'Grady Áine
Published: July 2015

Concerns about the environmental impacts associated with consumer products led to the development of environmental life cycle assessment (LCA) from the early 1990s and its codification by theInternational Standards Organization(ISO). This was followed by the realization of the consequences of other devices and systems. The need for the energy analysis and environmental appraisal of energy systems to be conducted on a life cycle basis, therefore, became evident. In a full or detailedLCA, the energy and materials used and pollutants or wastes released into the environment as a consequence of an activity or service are quantified over the whole life cycle, typically “from cradle‐to‐grave.” Such studies are often geographically diverse; that is, the energy and material inputs associated with the activity may be drawn from any continent or geopolitical region of the world. However, they enable a wide range of key environmental consequences to be examined as part of the device or system design process. There are four main stages ofLCA, which follow a logical sequence of goal definition and scoping, inventory analysis, impact assessment, and interpretation.LCAmethodology is critically reviewed from a state‐of‐the‐art perspective and illustrated using several energy sector case studies. These examples concern specific energy technologies, as well as the “whole systems” appraisal of national energy sectors and transition pathways. The current strengths and weaknesses ofLCAare identified for energy practitioners and policy analysts. Material has been incorporated on life cycle embodied energy and carbon accounting and comparisons made with related approaches, such as carbon and environmental footprinting.
Compressed Air Energy Storage (CAES)
Authors: Barnes Frank S. , Budd David A. , Lim Michelle , Freeman Eugene R.
Published: July 2015

The fundamentals of a compressed air energy storage (CAES) system are reviewed as well as the thermodynamics that makesCAESa viable energy storage mechanism. The two currently operatingCAESsystems are conventional designs coupled to standard gas turbines. Newer concepts forCAESsystem configurations include additions of heat recovery systems, air humidification, adiabaticCAES, hybrid, and isothermal systems, which are briefly discussed with respect to their underlying thermodynamics. The desired geological properties and constraint for large underground air storage systems are reviewed with special emphasis on geologic heterogeneity and the requirement of a thorough geologic site characterization. The financial considerations that are needed by managers who wish to consider the construction of aCAESsystem are presented and a variety of conditions whereCAESsystems are economically profitable are indicated.
High Temperature Electrolysis for Hydrogen or Syngas Production from Nuclear or Renewable Energy
Authors: Shi Yixiang , Luo Yu , Li Wenying , Ni Meng , Cai Ningsheng
Published: July 2015

High temperature electrolysis using solid oxide electrolysis cell (SOEC) is a promising method for converting electrical energy into chemical energy. The high temperature electrolysis is advantageous compared with low temperature electrolysis owing to its high electricity‐to‐hydrogen efficiency, fast reaction rate, and relatively low cost. The working principles and thermodynamics ofSOECforH2Oelectrolysis andH2O/CO2co‐electrolysis are described. The typical materials used forSOECare reviewed and technical challenges forSOECdurability are discussed. To further decrease the electrical energy consumption, fuel‐assistedSOECis proposed and demonstrated to be feasible for syngas production at very low electrical energy consumption or even power generation. The planar cell and tubular cells are identified as promising designs for commercialSOECapplications. AsSOECrequires both electrical energy and thermal energy input, the feasibility of integratingSOECwith nuclear power plant or renewable power plant for clean fuel production is discussed. Mathematical models at different levels contribute to understand the complex transport and reaction phenomena inSOECsand help optimize theSOECsystems. In the end, the challenges ofSOECand future developments are discussed. With further technological development, theSOECcould play an important role in future fuel processing, energy storage, and stabilizing the fluctuating renewable energy.
Smart Cities
Authors: Dahlquist Erik , Fell Terence
Published: July 2015

In 2012, for the first time, more people lived in cities than in rural areas. This is changing the conditions for everyone as fewer farmers should supply food for more people who are doing other things. The megacities also face very difficult traffic situations caused by smog and traffic jams. We could see very poor slum areas aside of very exclusive areas. This creates big differences between rich and poor. “Smart cities” can be seen as demonstrations of what we would like to see for all people in the cities. On the house roof, we see
PV
cells and solar power heaters as well as new type of wind power and small gardens with plenty of vegetables and fruits growing on it. Electrified collective communications as well as “car‐trains” reduce the emissions to air radically. The buildings are also designed to reduce the energy supply to a minimum, both in winter and summer time. You can get all food at home needed by sending a request to a supplier about what ingredients you need. The room contains 3D communication so that you can communicate with friends just like you were sitting in the same room. Waste water is treated locally by urine separation and solid organics fermented to produce biogas. As electric power is produced also locally by
PV
and cars have batteries, lamps are
LED
lamps, and so on, the system is, in many ways, transferred into a
DC
system instead of the totally dominating
AC
system today.
Smart Homes as Integrated Living Environments
Authors: Campillo Javier , Dahlquist Erik , Späth Ralf
Published: July 2015

Information and communication technologies have transformed nearly every single item in our life. From automatic steering control systems and anti‐blocking breaks in our vehicles to keep us safe, to ubiquitous tools for accessing news, real‐time weather data, instant messaging, social media, and entertainment right in our hands. Yet, most of our homes—taken as buildings for human habitation—have remained essentially unchanged for the past decades. In this article, some of the technologies available today for upgrading our conventional homes are presented. Special emphasis is put on building automation technologies as an integration of ICT into our living environment, in order to increase our comfort and quality of life while at the same time, help us reduce our homes energy usage and environmental footprint.
Chemical Looping Combustion and Gasification
Authors: Fan Liang‐Shih , Chung Elena Y. , Bayham Samuel C. , Kathe Mandar V. , Tong Andrew , Zeng Liang
Published: July 2015

With the emerging challenge of climate change and the continued escalation of energy demands, innovative and flexible fuel conversion technologies are necessary and gaining recognition. Chemical looping technologies have the potential to not only reduce energy costs, but also to mitigate carbon emissions. Historically, the general concept of this reduction–oxidation mechanism has been suggested, but the process was never commercialized. Recent interests in carbon capture techniques have revitalized the adaptive chemical looping system. Chemical looping technologies can utilize both gaseous and solid fuels such as natural gas and coal, respectively, for power, hydrogen, or chemical generation. However, the success of technological adoption requires a thorough understanding of the types of chemical looping techniques, the design considerations, and the reactor modes of configurations. Current large‐scale testing units are examined with the hope for near‐term advancement and future commercial application.
Tidal Current
Authors: Thomson Mat , Baldock Andrew J.
Published: July 2015

The idea of extracting useful, utility scale, energy from tidal currents has been the focus of much research and development over the past couple of decades. From the 1990s desk studies to the opening of the first MW scale test center in 2007 and now to the deployment and grid connection of several utility scale technologies, the tidal current energy sector is aiming for commercial‐scale deployment with the potential extraction of gigawatts of power for the United Kingdom and the rest of the world.

The extraction of tidal current energy offers the displacement of conventional fossil fuel generation and a diversification to the portfolio of electricity generating assets. The specific advantage of tidal current energy over other renewable energy sources is the predictable nature of the resource.

Similar to wind energy, the design drivers for tidal turbines are governed by the environmental conditions. It is essential to understand the complex nature of tidal flows and how the inflow conditions interact with the turbine and affect performance and loading.

A good understanding of the undisturbed tidal current resource, and its response to energy extraction, is critical to deployment of tidal current arrays. For large‐scale arrays over approximately 10MW, the use of hydrodynamic models that have been appropriately calibrated and validated using measured data is necessary. The complexity of estimating the tidal current resource means that understanding of the resource, and particularly how it is affected by energy exploitation, remains ongoing research. It is vitally important to differentiate between the total resource, theoretical resource, technical resource, and practical resource and definitions are provided in this article. Acceptable limits for parameters related to energy extraction (such as changes to tidal currents, tidal range, and sedimentation) have yet to be determined.
Energy‐Efficient District Heating
Authors: Li Hongwei
Published: July 2015

District heating uses hot water or steam as a carrier to transport energy produced from central heating plants to residential, commercial, or industrial buildings to provide their heating needs. It has the advantages to optimally use and combine a wide spectrum of low quality fuel, low temperature waste heat, and renewable energy. District heating improves energy efficiency on both the supply side and the demand side, and integrates with other energy infrastructures such as the electricity and gas grid. It represents an essential sustainable energy infrastructure with respect to energy security, energy efficiency, climate change, green economy, and social benefits. This article describes basic concepts for the district heating network and the building heating installations. In the district heating network, methods for district heating pipe thermal and hydraulic performance analysis are illustrated. Different types of consumer substations are introduced with emphasis on the heat exchanger dynamic performance, Legionella risk, and the flat station concept. The energy‐efficient district heating concepts and solutions with focus on fourth‐generation district heating and smart district heating are introduced. The renewable energy application and best practices in district heating are described. The demand side management in the district heating application is illustrated.
Green Labels and Standards for Appliances, Equipment, and Lighting
Authors: Zeng Lei , Yu Yang , Li Jiayang
Published: July 2015

Energy performance improvements in consumer products are an essential element in any government's portfolio of energy efficiency and climate change mitigation programs. As an effective policy tool, green labels and standards (S&L) can be widely applied to improve energy performance of appliances, equipment, and lighting globally. A well‐designed mandatory energy efficiency standard can remove cost‐ineffective, energy‐wasting products from the marketplace and stimulate the development of cost‐effective, energy‐efficient technology. Energy labels can empower consumers to make informed choices about the products they buy and to manage their energy bills, thus transform the market to achieve significant energy savings.

Over the past two decades, energy efficiency standards and labeling (S&L) programs have proven to be highly effective in stimulating the development of cost‐effective, energy‐efficient technologies in many countries. Economies such as the United States, European Union, China, and Japan have observed a rapid uptake of S&L programs as the cornerstone of their national energy and climate change mitigation programs. This report has taken a few examples of effective energy labeling systems from the United States,
EU
, China, Japan, Korea, and Australia to illustrate the wide application of green labels for appliances and prove that S&L are appropriate for most cultures and marketplaces and deserve to be the cornerstone of any country's energy policies and programs.
Adapting Policies for a New Energy Future
Authors: Simmons Richard A. , Secor Peter F. , Garimella Suresh V.
Published: July 2015

In this article, we consider current global energy trends and provide an overview of major initiatives developed to promote diversity of energy supplies and efficiency and policies and regulations aimed at curbing emissions. We not only investigate some of the underlying challenges associated with comprehensive energy legislation but also acknowledge the impact of successful technology and policy deployment at local, state, and regional levels. We examine the growing linkages between energy and the environment within policy dialogs at these various jurisdictions and identify some lessons learned and best practices.

The understanding that there is no one‐size‐fits‐all model is clearly borne out by the prevailing trends in energy throughout the world. Fossil fuels, although nettlesome environmentally, retain an important near‐term role overall. Shifts from coal to natural gas may add flexibility to the energy mix and prove beneficial to the environment in the short‐to‐medium term but must be complemented with longer‐term strategies. In balancing a clean energy agenda with pragmatic realities, we explore the policy context for a diversity of energy sources falling within two primary subsets of energy use: stationary and nonstationary. We review sources and trends, discussing them in view of crosscutting themes including: efficiency, conservation, alternative technologies, and metrics for environmental and economic impacts. Lessons learned indicate that the integration of new sources with conventional ones must no longer occur in a vacuum but in a coordinated manner. Multistakeholder dialog, real‐time data, and alignment of energy and climate policy objectives have become imperative. The suite of renewable energy options, although promising, must continue to overcome significant technological and financial barriers in order to compete in a subsidy‐free marketplace and to assure energy security. As such, the pros and cons of regulatory mandates, tax mechanisms, predetermined tariffs, and other policy initiatives are highlighted.

In the stepwise transition from higher carbon to lower carbon energy supplies, this article argues for the value of regional approaches and for better alignment among technological and policymaking communities. High impact energy advances and the policies that underpin them will be the ones that most fully optimize for positive impacts on energy security, the environment, and the economy.
Introduction: Energy Storage Technologies
Authors: Sioshansi Ramteen , Cabeza Luisa F. , Yan Jinyue
Published: July 2015

Energy storage has the potential to revolutionize electricity consumption and generation. This is because economic and efficient storage delinks the supply and demand sides of the electricity and other energy systems by introducing a viable inventory mechanism. A major technical challenge in this sphere is that useful energy is lost every time energy is converted from one medium to another. An equally important issue arises from the mixture of market‐based competition and traditional cost‐of‐service regulation in many parts of the world. This hybrid regulatory design can create impediments to fully capturing the value of all of the services that storage technologies can provide. A related issue that lies between the economic, regulatory, and technical issues is the wide variety of storage technologies available today. These technologies can be amenable to different applications, depending on their physical characteristics, and understanding the tradeoffs between the different technologies is vitally important for making storage investments viable. On the other hand, energy storage, mainly thermal energy storage (TES), is also used to decrease the energy demand of buildings and industry or to improve energy efficiency of energy system. The article in this volume touch on these and other issues related to energy storage.
Theory and Model of Energy Investment and Financing
Authors: Lu Bin , Ma Xiaowei , Feng Chao
Published: July 2015

Energy investment and financing is a very complicated problem that is influenced by various factors. To consider energy industry investment strategies and financing modes in a scientific and reasonable way, to build a stable, economical, clean, and safe energy supply system, and to avoid the recurrence and wild fluctuations of imbalance between energy supply and demand, the issue of energy investment and financing should be deeply discussed. This article introduces the features, modes, influencing factors, basic principles, and future development of energy investment and financing. The key viewpoints include the following: energy investment has four features including higher capital intensity, longer debt maturity, complicated risks, and uncertainty of profit. Domestic savings, international capital, and financial markets are the main sources and channels of energy financing. The country's energy development strategy, energy policy, macroeconomic environment, level of development of the energy market and financial market, financing risks, resource status, and characteristics of the energy industry are the major influential factors in energy investment and financing. To determine the financing mode of the energy industry, five basic principles should be followed: accordance with the national strategy of energy development, risk dispersal, diversification of financing channels, rationality of the control of energy enterprises, and risk management and risk aversion. The demand for energy investment in developed countries is slowing down, and transitioning and developing countries will lead the demand for global energy investment in the future. New energy and energy efficiency will gradually replace fossil fuel energy and become the major direction for future energy investment.
Market Instruments for Environmental Regulation: Emissions Trading in Practice
Authors: Chevallier Julien
Published: July 2015

The design of cap‐and‐trade programs can be flawed by various features such as initial allocation, banking and borrowing, geographic coverage, new entrant provisions, and so on that needs to be properly devised by the welfare‐maximizing social planner. This article reviews the essential characteristics that emissions trading schemes (ETS) should exhibit in order to avoid well‐known problems such as over‐allocation, exploitation of the resource rent by previously existing polluting companies, and the spectre of market power. Empirical examples are derived from the Kyoto Protocol, the European Union ETS, and some case studies of implementation of ETS at the regional or city level. This self‐contained article will allow market practitioners, institutions, and governments to plan accordingly the development of future tradable permits markets worldwide in a similar way.
Ice Storage
Authors: Okumiya Masaya
Published: July 2015

Thermal storage applied for heating, ventilating, and air conditioning (
HVAC
) system can shift energy demand from peak time to valley time. It results in effective use of energy infrastructure such as power generation and energy conservation, for example, owing to stable operation of heat source equipment. Typical storage media for
HVAC
application is water and ice. For ice storage, thermal energy is stored in both of the sensible heat and the latent heat of water (ice). It can reduce the volume of storage tank and is useful for the case of small or medium‐size building and existing building.

In this article, classification of ice storage according to the method for ice making and melting and how stored heat is transported to secondary side are discussed. Subsequently, some important issues such as control of the amount of ice and how total system efficiency can be maintained at high level are also discussed. The former is important for effective and safety operation of ice storage. Low temperature
HVAC
system is introduced as the measure to improve total system efficiency.
The Future of Energy Policy in East Asia: Prospects and Risks for a Sustainable Framework
Authors: Shiroyama Hideaki , Yoshikawa Hisashi , Orsi Roberto , Sato Chiaki
Published: July 2015

This article suggests two directions concerning energy policies in East Asia. First, even within the current regional framework, new roles can be reciprocally assumed by China, Korea, and Japan. Second, deeper cooperation with China and Korea should be sought in a more effective management of energy demand, from the sheer streamlining of energy‐related statistical standards to the diffusion of technological innovation, with a central role for the provision of knowledge, expertise, and infrastructure to the East Asian nations from Japan.

The evolution of the concept of energy security in East Asia is currently undergoing a historical change marked by both the explosive growth of energy demand in China and the worldwide “shale revolution.” But instead of assuming a rigid idea of security, the article accepts its pluralism and explores what conditions make even divergent conceptions of energy security as viable in the current and possibly future context of East Asia. Indeed, the golden principle of energy security has often been “to improve one's energy self‐sufficiency ratio and not to be dependent from external suppliers.” However, this concept of energy security may not be the most suited one for East Asia. Without a proper management of its rapidly increasing demand, it will become very difficult to improve the self‐sufficiency ratio in energy production for the Chinese economy, and East Asia as a whole. Also, the shale revolution is shaping a new global situation with a profound change of the supply–demand structure. As energy supply cannot be flexibly manipulated, East Asia, the region with the largest energy consumption, must however strive to design and to construct a secure energy supply system in the context of changing patterns of production and consumption, reflecting a global power shift.
The Role of National Agencies as Honest Brokers Between Science and Policy: Case Studies on Environmental Sustainability Indicators
Authors: Bordt Michael , Rastan Soheil
Published: July 2015

National agencies play important roles in developing the mission of their government and the vision of their nation. This review provides two examples of how national agencies, in particular, national statistical agencies and national environmental agencies are engaged in proactive interpretation of data and the role they play in the science‐policy interface, the interface where impartial evidence and values interact. The first example presents the science‐policy interface through experiences gained during the design, development, and dissemination of the Canadian Environmental Sustainability Indicators. The second example presents the science‐policy interface through experiences gained from understanding the issues related to the Pollution Standard Index of Singapore. Both examples highlight the means by which particular environmental sustainability indicators, for example, air quality, are collated, analyzed, and disseminated to the public. The examples underline the important role of national agencies as catalysts for honest brokering in the interface between science and policy.