Nikolaos E. Koltsaklis

An Integrated Unit Commitment and Generation Expansion Planning Model

Abstract This work presents a generic mixed integer linear programming (MILP) model that integrates the unit commitment problem (UCP) (daily energy planning) within the long-term generation expansion planning (GEP) framework. The model has been tested on an illustrative case study of the Greek power system. Our approach aims to provide useful insights into the strategic and challenging decisions to be determined by investors and/or policy makers at a national and/or regional level by providing the optimal energy roadmap according to specific assumptions and projections (e.g., electricity demand, fuel prices, and investment costs).

An integrated unit commitment model incorporating electric vehicles as a flexible and responsive load

Abstract This work presents a new optimization framework for the optimal operational planning of a large-scale power system taking into consideration the penetration of electric vehicles. This is a systematic approach in order to explore potential synergies among different energy sectors, i.e., the power and transport sectors. An illustrative real case study of the Greek power system is used to highlight the salient features and the applicability of the proposed modelling approach. The results determine the optimal production scheduling of the system integrating simultaneously the impacts of electric vehicles’ penetration into the grid.

Optimal scheduling of interconnected power systems

Abstract This paper presents an optimization-based approach to address the problem of the optimal daily energy scheduling of interconnected power systems in electricity markets. More specifically, a Mixed Integer Linear Programming model (MILP) has been developed to address the specific challenges of the underlying problem. The main focus of the proposed framework is to examine the importance and the impacts of electricity interconnections and cross-border electricity trade on the scheduling of power systems, both at a technical and economic level. The applicability of the proposed approach has been tested on an illustrative case study including five power systems which can be interconnected (with a certain interconnection structure) or not. The proposed model determines in a detailed and analytical way the optimal power generation mix, the electricity trade among the systems, the electricity flows (in case of interconnection options), the marginal price of each system, as well as it investigates through a sensitivity analysis the effects of the available interconnection capacity on the resulting power production mix. The work demonstrates that the proposed optimization approach is able to provide important insights into the appropriate energy strategies followed by the market participants, as well as on the strategic long-term decisions to be implemented by investors and/or policy makers at a national and/or regional level, underlining potential risks and providing appropriate price signals on critical energy infrastructure projects under real market operating conditions.

An Integrated Medium – Term Energy Planning Model for Interconnected Power Systems

Abstract This work presents a generic Mixed-Integer Linear Programming model that integrates a Mid-term Energy Planning model for the optimal integration of power plants into interconnected power generation systems. The time horizon consists of a representative day for each month of the year. The Unit commitment problem is modelled in details to optimally determine the optimal operational strategy in order to meet the electricity demand at a minimum total cost by utilizing the optimal combination of a set of available power generation plants. Furthermore, the model considers the possibility of building new units selected from a set of proposed ones, as well as expanding the capacity of existing renewable energy units. The possibility of expanding the existing interconnection capacity between systems is also considered. Environmental-related constraints for the production of CO2, NOX, SOX and PMX emissions are also taken into account. The main objective is the minimization of the total annualized cost. The applicability of the proposed model is illustrated in a case study including two interconnected power systems. Finally, a sensitivity analysis is performed in order to investigate the effect of key process parameters on the final power generation policies.

Reprint of: Optimal scheduling of interconnected power systems

Abstract This paper presents an optimization-based approach to address the problem of the optimal daily energy scheduling of interconnected power systems in electricity markets. More specifically, a Mixed Integer Linear Programming model (MILP) has been developed to address the specific challenges of the underlying problem. The main focus of the proposed framework is to examine the importance and the impacts of electricity interconnections and cross-border electricity trade on the scheduling of power systems, both at a technical and economic level. The applicability of the proposed approach has been tested on an illustrative case study including five power systems which can be interconnected (with a certain interconnection structure) or not. The proposed model determines in a detailed and analytical way the optimal power generation mix, the electricity trade among the systems, the electricity flows (in case of interconnection options), the marginal price of each system, as well as it investigates through a sensitivity analysis the effects of the available interconnection capacity on the resulting power production mix. The work demonstrates that the proposed optimization approach is able to provide important insights into the appropriate energy strategies followed by the market participants, as well as on the strategic long-term decisions to be implemented by investors and/or policy makers at a national and/or regional level, underlining potential risks and providing appropriate price signals on critical energy infrastructure projects under real market operating conditions.

Design and operational scheduling of power systems incorporating interconnection options

Abstract This work presents a generic Mixed Integer Linear Programming model that integrates a Mid-term Energy Planning model, which implements generation and transmission system planning at a yearly level, with a Unit Commitment model, which performs the simulation of the day-ahead electricity market. The applicability of the proposed model is illustrated in a case study of the Greek power system. The proposed modelling framework identifies (or not) the interconnection of an autonomous island to the mainland electric system, as well as the optimum interconnection capacity. It also quantifies the effects of the interconnection options in the day-ahead electricity market and on the energy mix. The proposed model can provide useful insights into the strategic and challenging decisions to be determined by investors and/or policy makers at a national and/or regional level, by providing the optimal energy roadmap and management, as well as clear price signal on critical energy projects under real operating and design constraints.

Design and Operational Planning of an Urban Energy Network based on Combined Heat and Power Generators

Abstract This work presents an optimization approach for the optimal design and operational planning of an urban energy network based on combined heat and power generators. The model is formulated as linear Mixed Integer Programming (MIP) and solved to optimality using standard branch-and-bound techniques. Optimality is assessed in terms of total system cost, while the applicability of the proposed model is illustrated using an illustrative example.