Jesus-Emmanuel Samouilidis

Project Ranking in the Armenian Energy Sector Using a Multicriteria Method for Groups

Project ranking is a complex problem that is often faced by the decision makers involved in the planning process. The necessity to take into account several decision parameters apart from purely economic ones, such as socio-political, technical, institutional and environmental, lead to the use of multicriteria methods instead of single uni-criterion ones. Moreover, most of the times such decisions are taken in a group environment. A hybrid of ELECTRE III and PROMETHEE methods, MURAME, has been specially developed and constitutes the main part of an integrated project ranking methodology for groups. The experience of the application of the methodology in the Armenian energy sector is presented.

A methodological approach to strategic petroleum reserves

Energy constitutes a small fraction of the production inputs in the economy, yet the rigidity imposed by the short and medium term inability to substitute energy with other production factors in case of an energy shortage, requires the establishment of safeguard mechanisms to ensure sufficient energy supply during an emergency. These safeguards usually take the form of strategic energy reserves. A methodological approach is presented here, relating the level of strategic petroleum reserves, the decision variable, with the costs associated with their storage and the economic losses incurred by an energy shortage. This approach is based on the use of a decision tree, to portray emergency scenarios. Each scenario, a branch of the decision tree, can be evaluated in terms of a cost function which includes the inventory procurement and maintenance cost and the shortage cost inflicted by a petroleum shortfall.

Energy modelling: A new challenge for management science

The Arab oil embargo in 1973 and the subsequent price rises and production restrictions have given birth to a distinct branch within Management Science: energy modelling. This paper gives a critical and selective review on energy modelling, an industry which though thriving in an era of general economic anxiety, is showing signs of arrogant immaturity. After giving a historical background, the paper classifies energy models into three groups: open loop demand or supply models; energy closed loop models; energy-economy closed loop models. For each group the problem area is analysed and some illustrative examples are described. In the last sections, an attempt is made to sum up the experience that has been gained with energy modelling: the basic deficiencies, the impact of this activity on policy formulation and its position within Management Science. It is concluded that energy models, though very poor forecasting devices, can be very useful to policy makers as tools for analysis; energy model developers must convince potential model users and for that purpose they can benefit immensely from the 35-year-long experience accumulated by their colleagues in Management Science.

On the optimal level of a small country's strategic petroleum reserve

Abstract Decisions relating to a countrys strategic petroleum reserve must take into account the level of risk inherent in its petroleum imports, the cost resulting from any shortfall in the import level, the cost of storage, and finally the effects of stockpiling transactions on the sensitive spot oil markets. Of course, small countries need not take into account their effect on the global market, a fact that drastically simplifies their decision problem. We present such a simple decision model for a small countrys petroleum reserve which in addition to the above factors take into account the uncertainty of the countrys refining capacity. A complete analytical treatment is feasible for this model, and a specific numerical example is presented for the case of Greece.

Multicriteria analysis of energy supply decisions in an uncertain future

This paper deals with energy supply investment decisions, related to the choice of technology, in an uncertain future. It develops a multicriteria approach, combining existing modern multicriteria techniques, to support these decisions and illustrates its application with a case study.

Multicriteria analysis using a large-scale energy supply LP model

Abstract A methodology and an application for performing multicriteria analysis using a large-scale energy supply linear programming model is presented. The methodology is applicable when the dimensions and the software of the model do not permit the use of a complicated multiobjective algorithm searching for a best compromise solution. It is based on a version of the constraint method for generating efficient solutions. A methodology is proposed for exploring progressively the set of efficient solutions and structuring the information obtained. This procedure provides abundant and easy-to-use information to the decision maker and assists him in choosing among alternative decision paths, thus reducing the efficient domain to be explored. The analysis is illustrated through an example using the Efom-Gresom energy supply model.

3.1. Short and medium-term modeling and problems of models linkage

In this paper we present the main theoretical and empirical issues encountered in the construction of a short/medium-term energy-economy linked system of models, namely the Hermes-Midas system. The paper focuses on the problems of model linkage and proposes a methodology. The Hermes-Midas Linked System covers all aspects of energy-economy simulation and policy analysis for European countries.

A model for the Greek energy system

Abstract The paper reports on a model ∗∗ describing the structure and operation of the Greek Energy System, which was developed for the quantitative evaluation of major energy policy decisions. The model is a multiperiod LP, formulated as to reflect the particular issues of the Greek energy situation. It can be used both as an optimization and a simulation device. A short description of the model is given, highlighting its distinctive features, followed by a sample of the solution. The paper also includes a brief critique of the model and a note on the models extensions, which are now in progress.

4.5. Multiobjective programming

The work presented in this paper focuses on the introduction of multiobjective programming methods into a large-scale energy systems planning model. We first review several multiobjective techniques, ranging from simple methods aiming at exploring the set of efficient solutions, to complex interactive algorithms providing best compromise solutions. We also review and apply an algorithm which implements a decentralized hierarchical decision process with multiple objectives. All methods are applied to versions of an existing large-scale linear programming model of the energy system. We evaluate these methods on a practical basis, concerning mainly the computational effort needed to implement the algorithms and the quality of the interaction with a decision-maker.

A simplified algorithm for the depot location problem

This paper describes a simplified optimization algorithm used for the solution of a classical depot location problem as presented in a Greek Manufacturing Company. Algorithms in the literature for this type of problem are based on the assumption of predetermined fixed costs which are independent of the final size of the depots. This assumption is usually far from reality; the size of each depot does not remain constant during the optimization process and so does the associated fixed cost which is variable with the size of the depot. This assumption is relaxed in the proposed algorithm; the associated fixed cost is modified each time a new customer is allocated to a depot thus changing the required depot size.