ECCO International

San Francisco, CA, United States

ECCO International

San Francisco, CA, United States

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Papalexopoulos A.,ECCO International | Andrianesis P.,ECCO International | Andrianesis P.,University of Thessaly | Philippou M.,Electricity Market Operator
IET Conference Publications | Year: 2016

Over the last 15 years, Virtual Power Plant (VPP) products have created significant interest and have become a popular instrument of competition policy. In this paper we present a high-level design of VPP products and auctions and a brief review of the international experience. We consider the application of VPPs in the Greek electricity market, intended to facilitate the opening of the retail market. We simulate the day-ahead market for a yearly period and discuss the results. We are mainly interested in the change of the incumbent's bidding behaviour as a result of the retail market opening and its impact on the market outcome.


Papalexopoulos A.D.,ECCO International | Andrianesis P.E.,ECCO International | Andrianesis P.E.,University of Thessaly
IEEE Transactions on Power Systems | Year: 2014

The emergence of high penetration of renewable energy sources in the energy mix of power systems has substantially increased the need for faster-ramping resources participating in the frequency regulation service procured via market mechanisms by the system operators. However, current market mechanisms do not properly align the incentives for participation since resources are not compensated for the actual frequency regulation they provide nor for the accuracy with which they follow the automatic generation control (AGC) dispatch signal. In this paper, we evaluate the current mechanisms for procuring, dispatching and compensating resources for the frequency regulation service. We also propose a comprehensive approach for calculating the performance payment that includes the actual service they provide and the accuracy with which they follow the AGC signal. Finally, we perform a study by deploying actual operational AGC data for analyzing the proposed methodology. © 2013 IEEE.


Papalexopoulos A.D.,ECCO International | Andrianesis P.E.,ECCO International | Andrianesis P.E.,University of Thessaly
Proceedings of IREP Symposium: Bulk Power System Dynamics and Control - IX Optimization, Security and Control of the Emerging Power Grid, IREP 2013 | Year: 2013

The design of restructured electricity markets requires a mechanism to ensure that differences between the bid-in demand that clears in the Day-Ahead Market (DAM) and the ISO's demand forecast do not compromise reliability requirements. This mechanism is usually called Reliability (or Residual) Unit Commitment (RUC), and is deployed to procure additional resources, beyond the DAM energy schedules, to meet the demand forecast. In this paper, we present the theoretical foundation of the RUC process and key important considerations in implementing the RUC application. We also provide a description of the general sequential approach in which the DAM application is executed first and then the RUC process is completed. We then offer the design framework for the implementation of an integrated approach which combines the functionality of the DAM and the RUC into one market application. The integrated approach offers substantial efficiencies by procuring all DAM products simultaneously. © 2013 IEEE.


Andrianesis P.,University of Thessaly | Liberopoulos G.,University of Thessaly | Kozanidis G.,University of Thessaly | Papalexopoulos A.D.,ECCO International
IEEE Transactions on Power Systems | Year: 2013

In centralized day-ahead electricity markets with marginal pricing, unit commitment costs and capacity constraints give rise to non-convexities which may result in losses to some of the participating generating units. To compensate them for these losses, a recovery mechanism is required. In Part I of this two-part paper, we present certain recovery mechanisms that result in recovery payments after the market is cleared. We also propose a methodology for evaluating the bidding strategy behavior of the participating units for each mechanism. In this paper (Part II), we apply this methodology to evaluate the performance and incentive compatibility properties of each recovery mechanism on a test case model representing the Greek joint energy/reserve day-ahead electricity market. Lastly, we perform sensitivity analysis with respect to key parameters and assumptions and we provide directions for further research. © 2012 IEEE.


Andrianesis P.,University of Thessaly | Liberopoulos G.,University of Thessaly | Kozanidis G.,University of Thessaly | Papalexopoulos A.D.,ECCO International
IEEE Transactions on Power Systems | Year: 2013

In centralized day-ahead electricity markets with marginal pricing, unit commitment costs and capacity constraints give rise to non-convexities which may result in losses to some of the participating generating units. Therefore, a recovery mechanism is required to compensate them. In this paper, we present and analyze several recovery mechanisms that result in recovery payments after the market is cleared. Each of these mechanisms results in a different type and/or amount of payments for each participating unit that exhibits losses. We also propose a methodology for evaluating the bidding strategy behavior of the participating units for each mechanism. This methodology is based on the execution of a numerical procedure aimed at finding joint optimal bidding strategies of the profit-maximizing units. In a companion follow-up paper (Part II), we apply this methodology to evaluate the performance and incentive compatibility of the suggested recovery mechanisms on a simplified test case model of the Greek electricity market. © 2012 IEEE.


Papalexopoulos A.,ECCO International | Beal J.,Raytheon Co. | Florek S.,ColorPower
IEEE Transactions on Smart Grid | Year: 2013

Even though demand response (DR) participation has substantial benefits to the market as a whole, current DR programs suffer from a collection of market, regulatory, infrastructure and technology problems, such as lack of scalability, lack of privacy, imprecision, and nonacceptance by customers. This paper describes how a fundamentally different DR approach, based on service priority tiers for appliances and on stochastic distributed computing, can overcome these problems and be integrated with energy markets. Our approach takes advantage of inexpensive communications technology to estimate the state of home and small-business major electrical appliances and have those appliances respond to power grid state signals within a few seconds. Organizing appliances into service priority tiers allows retail customer power demand to be de-commoditized, making these DR resources a potent force for improving the efficiency of energy markets. This paper describes the proposed methodology, examines how it can be integrated into energy markets, and presents results from mathematical analysis and from simulation of 100 000 devices. © 2013 IEEE.


Hansen C.W.,ECCO International | Papalexopoulos A.D.,ECCO International
IEEE Systems Journal | Year: 2012

This paper presents the methodology and the results of a study for determining the operational impacts and integration costs of high penetration of wind generation on various types of ancillary services and unit commitment scheduling for isolated systems. The methodology has been applied on the Greek Island of Crete. Three years of minute-by-minute telemetered load, wind speed, and wind generation data were deployed. This paper also analyzes the operational impact of curtailing excess wind for security purposes. © 2012 IEEE.


Papalexopoulos A.D.,ECCO International | Andrianesis P.E.,ECCO International
Proceedings - 2014 Power Systems Computation Conference, PSCC 2014 | Year: 2014

The restructured electricity markets typically involve a Day-Ahead Market (DAM), which clears bid-in demand that may be generally different (lower) than the demand forecast. This difference gives rise to reliability concerns to the Independent System Operators (ISOs), which are addressed with the deployment of a mechanism that is usually called Reliability (or Residual) Unit Commitment (RUC). Currently, the ISOs execute the RUC process after the DAM application, to procure additional resources, beyond the DAM energy schedules, to meet the demand forecast. In this paper, we compare the currently employed sequential approach, with a proposed integrated approach which combines the functionality of the DAM and the RUC into one market application. We present the market model including all market commodities, namely energy, ancillary services and RUC capacity, for both methodologies, and apply them on a realistic test case, using actual market/system data. We derive quantitative and qualitative results for a practical system, which illustrate the value of the integration of the market and the reliability functions in the forward spot market. The key conclusion from our simulation runs, is that the integrated approach offers substantial efficiencies by procuring all DAM products simultaneously. © 2014 Power Systems Computation Conference.


Papalexopoulos A.,ECCO International
IEEE PES General Meeting, PES 2010 | Year: 2010

We examine the impact of the friction that exists between wholesale energy markets and system operations on the efficiency of the market outcomes. We elaborate on some basic implications of system operation practices on the design of wholesale energy markets. This analysis is intended to provide a basis for enhancements to existing principles of system operation and bridge the gap between energy market design and system operations. ©2010 IEEE.


Andrianesis P.,ECCO International | Papalexopoulos A.D.,ECCO International | Papathanassiou S.,National Technical University of Athens
IET Conference Publications | Year: 2014

In this paper, we address the recently established regulatory framework for the management of the Greek Non-Interconnected Islands (NII) power systems. We present the recent initiatives for the development of Energy Control Centers, including Energy and Market Management Systems, and we provide an overview of the proposed systems architecture. In addition, we list a formulation of the basic market process for the implementation of a NII electricity market, i.e., the Rolling Day-Ahead Scheduling, which captures key features of the regulatory framework. To illustrate the model, we use as a test case a particular NII.

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