Athanasios Tolis

Electricity and combined heat and power from municipal solid waste; theoretically optimal investment decision time and emissions trading implications

Waste management has become a great social concern for modern societies. Landfill emissions have been identified among the major contributors of global warming and climate changes with significant impact in national economies. The energy industry constitutes an additional greenhouse gas emitter, while at the same time it is characterized by significant costs and uncertain fuel prices. The above implications have triggered different policies and measures worldwide to address the management of municipal solid wastes on the one hand and the impacts from energy production on the other. Emerging methods of energy recovery from waste may address both concerns simultaneously. In this work a comparative study of co-generation investments based on municipal solid waste is presented, focusing on the evolution of their economical performance over time. A real-options algorithm has been adopted investigating different options of energy recovery from waste: incineration, gasification and landfill biogas exploitation. The financial contributors are identified and the impact of greenhouse gas trading is analysed in terms of financial yields, considering landfilling as the baseline scenario. The results indicate an advantage of combined heat and power over solely electricity production. Gasification, has failed in some European installations. Incineration on the other hand, proves to be more attractive than the competing alternatives, mainly due to its higher power production efficiency, lower investment costs and lower emission rates. Although these characteristics may not drastically change over time, either immediate or irreversible investment decisions might be reconsidered under the current selling prices of heat, power and CO 2 allowances.

The effect of long-term expansion on the evolution of electricity price: numerical analysis of a theoretically optimised electricity market

Abstract A decision support tool is proposed for optimising the expansion planning of a semi-liberalised electricity market, whilst the underlying interaction of the generating mix with electricity prices is researched, in the long-run. A nonlinear stochastic programming algorithm is used for handling multiple uncertainties, optimising the power sector characteristics, both in terms of financial and environmental performance. Two endogenous models and an exogenous one are analysed and compared. The endogenous model results indicate that consumers might benefit by the moderate electricity prices in case the optimal loads and capacity orders are rendered. The exogenous model is insensitive to generating mix variations. The long-term actions suggested for system operators are comprised of the permits issued for new entries. They are affected by the evolution of electricity prices, since the permits granted for conventional technologies are maintained when their profits are rising. The permits granted for renewable technologies are also maintained, thus allowing cleaner electricity production to be induced to the grid. The optimal bid strategies of generators interact with their dispatching schedule and the diversification of their load curves. The relevant bids are primarily driven by the merit order, the plants are dispatched in. The assigned load levels may be raised in profitable producers so that their profit is maximised. They might be restrained instead, in case there are no significant prospects for individual profits. The lognormal distribution of electricity price results is characterised by increasing variance over time, indicating that the model is more robust in the most imminent solutions.

SUSTAINABILITY AND THE OLYMPICS: THE CASE OF ATHENS 2004

The terms of growth and environment are historically proven not to be compatible, in principle, methods and targets. Economic investments are usually accompanied by actions that could not easily be characterized as environmentally friendly, while the strict application of environmental directives often results in halting development. Moreover, the tendency to constant economic growth is a desirable and inherent characteristic of human nature, which is apparently not to be changed in the near future. In this context, the pressing need for a bundle of approaches that could tie the objectives of economic growth and the protection of the environment had led to the field of sustainable development. The compatibility of each investment project with the principles of sustainable development should be therefore a matter of high priority. This text addresses the sustainability and the impact of the Olympic Games that were held in Athens in the summer of 2004. The Olympics comprise the biggest of events and their preparation extends in a scale capable of restructuring various spheres of economic activities. The sustainability issues that arise are therefore of major importance. The paper concerns the impact assessment of Olympic investments, in terms of properly selected and modified sustainable performance indicators focusing mainly on economy and environment. In this context, data and facts concerning the total budget of the Games are presented, while the attempt to monitor the evolution of the Games’ economic context focuses finally on the volume of labor force and unemployment rate. Regarding the environmental sphere, the sustainability of the Games is assessed mainly through the areas of interest of transport networks, traffic and pollution among others. Eventually, the article presents a holistic approach of assessing the sustainable impact of the Olympic Games and its implementation on the Athens 2004 Games.

Effect of greenhouse gas emissions trading on investment decisions for biomass-to-energy production

This chapter looks at the effect of greenhouse gas emissions trading on investment decisions for biomass-to-energy production

Decisions under uncertainty in municipal solid waste cogeneration investments

The issue of Municipal Solid Waste (MSW) management is an ever increasing problem for all countries. Developed countries face the problem of dealing with very large amounts of MSW per capita, forcing them to develop new technologies and systems. On the other hand, countries with developing or transitional economies may generate lower amounts of MSW per capita, but the rate of increase is high and the current practices of MSW management are not as advanced as those of developed countries. Therefore, countries with developing or transitional economies may benefit from adopting MSW management technologies used by developed economies. One aspect of MSW management in developed economies is the energy recovery from MSW. The advantages of this type of technologies are mainly the significantly reduced waste volume for landfilling, the reduction of total greenhouse gas emissions, the potential for generating electricity or co-generation of electricity and heat. In this work, a comparative study of the most prominent co-generation technologies using MSW as a fuel source is presented, focusing on the evolution of their economical performance over time. An algorithm based on real-options has been applied for four technologies of MSW energy recovery: (1) incineration, (2) gasification, (3) landfill biogas exploitation using a pipeline system and (4) anaerobic digestion facilities. The financial contributors are identified and the impact of greenhouse gas trading is analyzed in terms of financial yields, considering landfilling as the baseline scenario. The greenhouse gas trading system presents an opportunity for investing in environmentally friendly technologies for MSW energy recovery, through the Clean Development Mechanism (CDM), in most developing countries. The results of this work indicate an advantage of combined heat and power over solely electricity generation. The most attractive technology among the ones examined proves to be incineration, mainly due to its higher power production efficiency, lower investment costs and lower emission rates. Despite the fact that these characteristics may not drastically change over time, either immediate or irreversible investment decisions might be reconsidered under the current selling prices of heat, power and CO2 allowances.

An enhanced real coded approach for the optimization of the Unit Commitment Problem

In the present study, a novel enhanced real-coded approach is proposed for the simultaneous optimization of Unit Commitment and Economic Dispatch. In the proposed method, the objective variables represent the power generated by each unit at each hour. By utilizing the operational characteristics of each unit, its states and generation levels during the scheduling period are optimized concurrently. Moreover, a repair mechanism, which stochastically adjusts the generation of the units, is implemented to ensure the feasibility of the derived operation schedules. The solver employed for the optimization of the Unit Commitment Problem using the proposed method is L-SHADE, which is a state-of-the-art adaptive algorithm based on Differential Evolution. The real-coded approach is tested on a set of power systems consisting of up to 100 thermal units, available in the literature. The experimental results indicate that the proposed method exhibits more robust solution distributions and lower minimum operation cost for large scale systems compared to other state-of-the-art methods.