Modelling decentralized decision making in the energy sector

Large linear programming models, which have been widely used to determine the optimal structure of national energy systems, are based on the assumption that there is an absolutely centralized decision making process within the energy system. In this paper an attempt is made to match the real decision structure of a given energy system, by decomposing an LP energy model into smaller models, with the corresponding system decision centres. This is done by applying the ‘transfer price’ algorithm of Dantzing and Wolfe. The ‘master’ problem corresponds to the central planning unit, i.e. a Ministry of Energy, whereas the subproblems correspond to peripheral operating units, i.e. enterprises, usually state owned, which produce and distribute the energy carriers. The optimal plans of the peripheral units are submitted to the central unit, which through the mechanism of pricing of both common resources, inputs and energy services outputs, co-ordinates the overall planning of the energy system. An illustrative example is given referring to the Hellenic national energy system. The research reported is placed within a wider research endeavour, whose objectives and main line of work are also given.     

A model for forecasting energy economic systems

This paper presents a small integrated model which can be used for forecasting the behaviour of energy economic systems. The model is small, particularly when compared with the huge econometric modelling systems that are being used for the same purpose, and it is integrated in the sense that it forecasts both energy demand and gross domestic product simultaneously, taking into account the two way linkage existing between them. The energy economic system is formulated in a linear dynamic mode and Kalman filter is used for estimating the model. It is also applied for forecasting the state of the system in the future. The implementation of the model to the Greek energy economic system is presented as a case problem.     

OMEGa: an optimistic most energy gain method for minimum energy multicasting in wireless ad hoc networks

In wireless ad hoc networks where every device runs on its own battery, the energy consumption is critical to lengthen the network lifetime. The communication among devices in the network can be categorized as unicasting and multicasting (including broadcasting). For the case of unicasting, computing the energy optimal path between the two communicating nodes is polynomially solvable by computing the shortest path. But for the case of multicasting, shortest path or minimum spanning tree does not guarantee an energy optimal communication. In this paper, we present our novel approach, Optimistic Most Energy Gain (OMEGa) method, for the minimum energy multicasting in wireless ad hoc networks. OMEGa aims at maximum utilization of Wireless Multicast Advantage (WMA), which essentially means covering more nodes by using larger energy. Both theoretical and experimental analysis shows OMEGa method performs very well. Research is partially supported by NSF and Air Force grants.     

Electricity planning vs energy planning: A modelling approach

An essential part of the energy policy making process is the co-ordination of the sub-sectorial plans of energy producers in order to ensure that they are compatible with the broader goals of the global energy system. In this paper an attempt is made to underline the significance and estimate the size of this problem through an interplay of two optimization models; a global energy system model and an electricity subsystem model. The possibility of model interlink, leading to a higher level of co-ordination, is discussed.     

GREPOM: An energy policy model

Energy policy analysis and energy modelling as applied in the case of Greece are reviewed. A complex of energy policy models in synergy is presented. These models have been developed by the Energy Policy Unit of the National Technical University of Athens and constitute the framework for analysing specific medium- and long-term policy options. A case study involving the use of new energy technologies is described. Scenarios relating to the penetration rate of new energy technologies are analysed and respective policy implications are discussed. A general conclusion to the research conducted is that with parallel work on both the content of specific policy issues and the policymaking process in general, substantial progress could be made in improving the decision-making potential of public policy organizations.     

The energy manager and his corporate role

Energy management is technical and innovation oriented and the manager needs specific skills. The author identifies these skills and their application to the process of development energy management objectives, and the short, medium and long term strategies necessary for energy conservation.     

The corporate energy policy: A management planning perspective

The energy problems facing the world have been receiving increasing attention in the press and in business journals. This article examines the attitudes of 224 U.S. business executives toward the energy crisis and examines the role of a corporate energy policy in minimizing the economic impact of future energy price increases and/or shortages. A plan for a corporate energy policy is proposed.     

Revitalising energy capital project development and execution strategies: lessons from the energy sector

This study sought to examine project delivery challenges currently being faced by energy clients and to determine how they could achieve value creation through better alignment of project delivery processes. There are important lessons to be learned from the energy sector on how to deal with the unique operational and project challenges. Four exploratory focus groups were held with twenty senior project management practitioners, to better understand the greatest needs and project management processes in the energy sector. A formal deductive approach was used to examine and evaluate existing and future energy project delivery processes. From the qualitative data, participants recognised the need to introduce science-based project techniques such as system dynamics and project predictive analytics in project management processes. Participants further noted that comprehensive innovative project delivery processes and analytical approaches are required to cope with the increasing scale and complexity of energy capital projects.     

Solar energy: Where policy-makers and conservationists disagree

Solar energy policy-makers and solar energy advocates use significantly different scenarios upon which they perceive and evaluate the adoption of solar technologies. The differences between the two groups seem to be rooted in different hierarchies of values relating to solar energy policy. Policy-makers emphasize the economic and national security values of solar energy. On the other hand, solar energy advocates stress environmental, ethical and social values. Aside from understanding the different groups in the on-going energy debate better, the findings of the study have important implications for planners both in government and industry as they may help increase the effectiveness of their plans.     

A regional end use energy demand model

This paper describes a long-term energy demand forecasting model for Northern Ireland. The model is of the ‘what-if’ type for testing possible futures described by the model user and is based on a detailed activity analysis approach. The demand subsystem of the Northern Ireland energy system is divided into seven sectors and the demand for four end use categories for fuels considered. The structure of each of the seven sectors is modelled and future fuel demands calculated based on the driving functions of population and social and economic activity. For a given input scenario the model calculates the dockside oil equivalent primary fuel in tonnes for each year for 30 years.     

Technological change and energy consumption in US iron and steel manufacturing

This paper examines the extent to which the rising relative energy prices of the past decade have influenced managerial decisions in U.S. iron and steel manufacturing. Efforts at energy conservation, as well as opportunities for short-run substitutions among energy sources, were constrained mainly by existing process technology. The actual pattern of substitution can be explained to a large extent by changes in techniques. Decisions concerning such investments were guided by many factors, among which considerations of energy savings played only a minor role. This observation can be explained by the fact that, although the industry in the aggregate is a prodigious consumer of energy, energy costs at any one production stage are but a small fraction of total variable costs. Integrated greenfield plants embodying state-of-the-art technology would achieve much higher levels of energy efficiency than are currently realized, but such new plants are unlikely to be built in the United States, under the current conditions of global excess capacity.     

The EFOM 12C energy supply model within the EC modelling system

This article describes the EC-EFOM 12C model in general and refers where possible to existing documentation. It also reports on the first completed experimental case study and on planned future analysis. This model was developed in one of the research programs undertaken by the European Commission aimed primarily at multinational studies. Data are obtained from research carried out by an interactive network of national implementation teams working with a central group at the Commission. The energy system used is an oriented network carrying the primary energy over intermediate stages till finally meeting consumers' demand. The numerical information, constituting the attributes that characterise the various energy transformation processes, is stored in the European energy data base. About 225 transformation processes distributed over 17 subsystems characterised for six time periods up till 2020 for all EC countries are involved. The management of the data base is performed by an interactive software and this data base is designed for use in simulation studies and for linear programming optimisation with various objective functions. The model has been used in a parallel case study to explore substitution possibilities between an investment policy reducing the primary energy imports and one where these investments are restrained at the cost of having to import more primary energy. Results are shown and briefly discussed. Finally the relationship of this EFOM 12C model with the other EC models developed in the same research subprogram is outlined.     

Inside the black box: incentive regulation and incentive channeling on energy markets

This paper aims to achieve more insight into the complex interplay between the “external” market regulations and “internal” regulations (corporate governance) of energy firms. In recent years, many countries have deregulated the incumbent energy monopolies and have introduced new modes of regulation. However, the new incentive schemes do not represent an unmitigated success story. A major problem seems to be the neoclassical framework that is used for the analysis of energy markets. Therefore, an important goal of this paper is to clarify the boundaries of neoclassical regulation theory. There are two restrictions that hamper the neoclassical analysis of energy markets. The first is the difficulty of overcoming the widely held “black box” view of firms. The second is the idea that agents always make rational choices. The paper proposes a kind of theoretical division of labor for understanding the effectiveness of regulatory schemes in energy markets. Neoclassical economics points out to the sources of market failure, and helps to identify where in particular on the supply chain one is likely to observe natural monopolies. Transaction cost economics explains appropriate governance of vertical relations along the supply chain. And organizational theories can elucidate what happens within firms: their response to regulation, competition, and relations with suppliers. A research agenda for the third component is proposed, drawing on insights from New Sociological Institutionalism and organizational behavior.     

Developing an energy conservation program at united technologies corporation

In this article, the authors explain United Technologies Corporation (UTC) efforts to develop and design a natural resource conservation program; establish a worldwide baseline inventory of energy consumption; develop corporation-wide conservation goals; and develop and implement systems and procedures to collect and analyze relevant data and measure performance.Since there are no federal regulatory programs requiring energy conservation or greenhouse gas emissions reporting, UTC has the flexibility and the time to develop a model program appropriate to its own organizational needs. The authors present this model as an example of a successful pragmatic program to measure and report energy consumption at the corporate level.     

World energy resources and the limitations of computer modelling

The views of Meadows and the Club of Rome are challenged in the first part of this article, which reviews available information on world energy reserves. Here the conclusion is reached that the real nature of the energy ‘crisis’ is not one of impending resource exhaustion, but of economic, social and political problems stemming from rising prices and the uneven distribution of world reserves. Part Two takes up the question ‘How far are large computer models likely to be relevant for the formulation of energy policy?’ It concludes that they can be a useful tool for analysing complex relationships and portraying future scenarios, but they should not be seen as a substitute for policy choices.     

Layouts for ocean wave energy farms: Models,properties, and optimization

Renewable energy, such as wave energy, plays a significant role in sustainable energy development. Wave energy represents a large untapped source of energy worldwide and potentially offers a vast source of sustainable energy. We present models and a heuristic algorithm for choosing optimal locations of wave energy conversion (WEC) devices within an array, or wave farm. The location problem can have a significant impact on the total power of the farm due to the interactions among the incident ocean waves and the scattered and radiated waves produced by the WECs. Depending on the nature of the interference (constructive or destructive) among these waves, the wave energy entering multiple devices, and thus the power output of the farm, may be significantly larger or smaller than the energy that would be seen if the devices were operating in isolation. Our algorithm chooses WEC locations to maximize the performance of a wave farm as measured by a well known performance measure called the q-factor, which is the ratio of the power from an array of N WECs to the power from N WECs operating independently, under the point absorber approximation. We prove an analytical optimal solution for the 2-WEC problem and, based on the properties of the 2-WEC solution, we propose an iterative heuristic optimization algorithm for the general problem.     

Race to idle or not: balancing the memory sleep time with DVS for energy minimization

Reducing energy consumption is a critical problem in most of the computing systems today. Among all the computing system components, processor and memory are two significant energy consumers. Dynamic voltage scaling is typically applied to reduce processor energy while sleep mode is usually injected to trim memory’s leakage energy. However, in the memory architecture with multiple cores sharing memory, in order to optimize the system-wide energy, these two classic techniques are difficult to be directly combined due to the complicated interactions. In this work, we explore the coordination of the multiple cores and the memory, and present systematic analysis for minimizing the system-wide energy based on different system models and task models. For tasks with common release time, optimal schemes are presented for the systems both with and without considering the static power of the cores. For agreeable deadline tasks, different dynamic programming-based optimal solutions are proposed for negligible and non-negligible static power of cores. For the general task model, this paper proposes a heuristic online algorithm. Furthermore, the scheme is extended to handle the problem when the transition overhead between the active and sleep modes is considered. The optimality of the proposed schemes for common release time and agreeable deadline tasks are proved. The validity of the proposed heuristic scheme is evaluated through experiments. Experimental results confirm the superiority of the heuristic scheme in terms of the energy saving improvement compared to the most related existing work.     

Three energy scenarios for the United Kingdom

The general principles of constructing scenarios and using them to explore policy options have been described in an earlier paper¹. This paper summarizes the results of a preliminary examination of the three scenarios described there and referred to as ‘business-as-usual’, ‘technical-fix’ and ‘low-growth’. The investigation departs from conventional discussions of fuel policy in that it emphasizes the management of fuel demand, and the interaction between fuel demand and life-style, rather than emphasizing fuel supply policies. The relationship between life style and fuel demand can be quantified using the methods of energy analysis.² This method is capable of fine disaggregation and relatively high accuracy. However the aim of the studies reported here was to establish the range of feasible options and the types of policies needed to accomplish them. For this purpose high accuracy is not important so considerable data aggregation has been retained. The detailed analyses presented in this paper are estimated to be accurate to ±15 per cent.The first part of the paper sets out the analysis of the base year (1968) on which the future projections are based. This involves explaining the principles of energy analysis and the method of projection used. The next sections examine the three scenarios in some detail, starting with the estimation of fuel demand and then looking at the fuel supply and management policies needed.     

Prerequisites of efficient decentralized waste heat recovery and energy storage in production planning

Following the scarcity of resources, rising energy prices, and an increasing awareness of the role manufacturing plays in the generation of greenhouse gas emissions, the usage of energy has more and more been considered in research on production planning and scheduling in recent years. Time-varying energy prices, which have been introduced to penalize energy usage during peak-demand periods and which are supposed to smooth energy demand, have added a new aspect to this stream of research. This article studies how the integration of a waste heat recovery system, which can convert industrial waste heat into electrical energy, along with an electrical energy storage system can balance the positive and negative effects of energy peak prices on the production plan in a serial multi-stage production system. After developing an appropriate model, we investigate how the use of the waste heat recovery system and the electrical energy storage system impact production planning. In a numerical analysis, we investigate under which conditions the recovery of waste heat combined with the opportunity to store energy provides practitioners with an efficient tool to lower total energy usage and to better react to time-varying energy prices, and thus to reduce total energy cost.     

Modeling for insights,not numbers: the experiences of the energy modeling forum

It has often been contended that the primary goal of policy modeling should be the insights quantitative models can provide, not the precise-looking projections—i.e. numbers—they can produce for any given scenario. Students of the energy policy process, in particular, have noted that preoccupation with the plethora of detailed quantitative results produced by large-scale computer models has substantially impeded their influence on key policy decisions. The creation of the Energy Modeling Forum (EMF) at Stanford University in 1976 represents one potential remedy for that situation. The EMF was formed to foster better communication between the builders and users of energy models in energy planning and policy analysis. The EMF operates through ad hoc working groups, composed of national and, more recently, international energy modeling and policy experts. These working groups conduct studies concentrating on a single energy topic. The diversity of backgrounds of the working group members ensures that the language of the EMF studies is English, not computer. Each working group identifies existing models relevant to the study's focus. A series of tests is then designed by the group to illuminate the models' basic structure and behavior. A comparison of results is published in a widely distributed report that identifies the models' strengths and weaknesses in the context of the study's topic. Seven EMF studies have been initiated to date: (1) Energy and the economy, (2) Coal in transition, (3) Electric load forecasting, (4) Aggregate elasticity of energy demand, (5) US oil and gas supply, (6) World oil and (7) Macroeconomic impacts of energy shocks. Each EMF study has broadened the understanding of the nature of the relevant policy issues and the models that have been, are, or could be used to address them. The present paper describes how each study's key insights were developed in the context of a simplified analytical framework that provided the proper perspective for understanding the model results.