Alex Papalexopoulos

Dr. Alex Papalexopoulos

CEO, ECCO International, CEO & Chairman of the Board, ZOME E...

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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26 December 2020 in Applied Sciences
Verified
Journal Article
Open access
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KAKonstantinos-Nikolaos Andriopoulos
Konstantinos-Nikolaos Andriopoulos
AMAris Magklaras
Aris Magklaras
Alexios BirbasAlexios Birbas
Alexios Birbas
APAlex Papalexopoulos
Alex Papalexopoulos
CVChristos Valouxis
Christos Valouxis
GPGeorge Papaioannou
George Papaioannou
The continuous penetration of renewable energy resources (RES) into the energy mix and the transition of the traditional electric grid towards a more intelligent, flexible and interactive system, has brought electrical load forecasting to the foreground of smart grid planning and operation. Predicting the electric load is a challenging task due to its high volatility and uncertainty, either when it refers to the distribution system or to a single household. In this paper, a novel methodology is introduced which leverages the advantages of the state-of-the-art deep learning algorithms and specifically the Convolution Neural Nets (CNN). The main feature of the proposed methodology is the exploitation of the statistical properties of each time series dataset, so as to optimize the hyper-parameters of the neural network and in addition transform the given dataset into a form that allows maximum exploitation of the CNN algorithm’s advantages. The proposed algorithm is compared with the LSTM (Long Short Term Memory) technique which is the state of the art solution for electric load forecasting. The evaluation of the algorithms was conducted by employing three open-source, publicly available datasets. The experimental results show strong evidence of the effectiveness of the proposed methodology.

26 February 2024 in IEEE Access
Verified
Journal Article
Open access
KAKonstantinos-Nikolaos Andriopoulos
Konstantinos-Nikolaos Andriopoulos
KPKonstantinos Plakas
Konstantinos Plakas
Alexios BirbasAlexios Birbas
Alexios Birbas
APAlex Papalexopoulos
Alex Papalexopoulos
The energy sector is undergoing a transformative shift, driven by advancements in Distributed Energy Resources (DERs), the digitization of the energy supply chain and decarbonization policy objectives across the world. This paradigm shift has led to the emergence of Local Energy Markets (LEMs), which enable small-scale prosumers to actively participate in the energy market, trade power, and leverage their flexible resources. To ensure the success and acceptance of LEMs, this paper proposes a cooperative game-theoretic approach that fosters prosumer engagement and fair profit allocation. We utilize prospect theory from behavioural economics to examine the decision-making process of prosumers and incorporate their preferences for changes in wealth status. By adopting a cooperative game structure, prosumers can pool their resources, reduce transaction costs, and enhance data utilization. The paper introduces a novel pricing algorithm inspired by prospect theory that incentivizes prosumer participation and accounts for the uncertainty involved in LEM operations. Additionally, a computationally efficient method for profit allocation based on the variation of the Shapley value is proposed to ensure scheme stability. A use case evaluation is conducted on a real-world low-voltage network, demonstrating the effectiveness of the proposed approach in terms of economic efficiency and market characteristics. The results highlight the benefits of the consumer-centric LEM, including improved local trading dynamics, fair profit distribution, and enhanced grid stability. Overall, this research contributes to the design and development of LEMs that prioritize prosumer engagement, community cooperation, financial inclusion and democratization of the energy market.

6 October 2021 in IEEE Transactions on Cloud Computing
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Journal Article
Closed access
ABAthanasios Bachoumis
Athanasios Bachoumis
KAKonstantinos-Nikolaos Andriopoulos
Konstantinos-Nikolaos Andriopoulos
KPKonstantinos Plakas
Konstantinos Plakas
AMAristeidis Magklaras
Aristeidis Magklaras
PAPanayiotis Alefragis
Panayiotis Alefragis
APAlex Papalexopoulos
Alex Papalexopoulos
The massive penetration of Renewables into the energy mix and the existence of IoT-enabled Distributed Energy Resources (DERs) in the emerging smart grid, while a blessing towards de-carbonization, increase considerably the operations and planning functions of the grid. Cloud processing of IoT/DER data facilitates the deployment of various Demand-Response (DR) and other DER asset scenarios, the organization of distribution grids into Local Energy Markets (LEM) and the efficient computation of load forecasting and power flow. Cloud computing enables a plethora of service provisions to the grid including frequency response. The decentralized nature of DERs at the edge of the distribution grid requires nodal approaches for the computation of power grid congestion constraints and power flow solutions. We present here a cloud-edge continuum approach, anchored on the new generation of communications infrastructure, which expedites the computation time of the load and DER forecasting and optimal power flow calculations. The proposed approach allows the LEM operator to respond to Fast Frequency Response service procurement signals issued by the balancing authority requiring even sub-second latency for service settlement. The proposed cloud-edge architecture has been tested on the IEEE European Low Voltage Benchmark model and provides scalability and elasticity for various DR/DER configurations.

30 January 2023 in Applied Sciences
Verified
Journal Article
Open access
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KAKonstantinos-Nikolaos Andriopoulos
Konstantinos-Nikolaos Andriopoulos
KPKonstantinos Plakas
Konstantinos Plakas
CMChristos Mountzouris
Christos Mountzouris
JGJohn Gialelis
John Gialelis
Alexios BirbasAlexios Birbas
Alexios Birbas
APAlex Papalexopoulos
Alex Papalexopoulos
The upward trend of adopting Distributed Energy Resources (DER) reshapes the energy landscape and supports the transition towards a sustainable, carbon-free electricity system. The integration of Internet of Things (IoT) in Demand Response (DR) enables the transformation of energy flexibility, originated by electricity consumers/prosumers, into a valuable DER asset, thus placing them at the center of the electricity market. In this paper, it is shown how Local Energy Markets (LEM) act as a catalyst by providing a digital platform where the prosumers’ energy needs and offerings can be efficiently settled locally while minimizing the grid interaction. This paper showcases that the IoT technology, which enables control and coordination of numerous devices, further unleashes the flexibility potential of the distribution grid, offered as an energy service both to the LEM participants as well as the external grid. This is achieved by orchestrating the IoT devices through a Consumer Digital Twin (CDT), which facilitates the optimal adjustment of this flexibility according to the consumers’ thermal comfort level constraints and preferences. An integrated LEM-CDT platform is introduced, which comprises an optimal energy scheduler, accounts for the Renewable Energy System (RES) uncertainty, errors in load forecasting, Day-Ahead Market (DAM) feed in/out the tariff, and a fair price settling mechanism while considering user preferences. The results prove that IoT-enabled consumers’ participation in the energy markets through LEM is flexible, cost-efficient, and adaptive to the consumers’ comfort level while promoting both energy transition goals and social welfare. In particular, the paper showcases that the proposed algorithm increases the profits of LEM participants, lowers the corresponding operating costs, addresses efficiently the stochasticity of both energy demand and generation, and requires minimal computational resources.

1 May 1995 in IEEE Transactions on Power Systems
Verified
Journal Article
Closed access
SHShangyou Hao
Shangyou Hao
APAlex Papalexopoulos
Alex Papalexopoulos
--- Traditional external network modeling techniques have been widely used in the power,industry to produce equivalent models that are suitable for power flow analysis and security assessment applications. These techniques cannot beused,to produce ,models ,for Optimal Power Flow applications. In this paper, we present a new methodology that is suitable for security analysis and security control. The proposed method,has been tested extensively under a wide variety of operating conditions using data from a large scale system. The results strongly indicate that the proposed method outperforms,the Extended Ward ,method ,in producing equivalent models for security control and does not create an additional burden,in maintaining and,updating the EMS database. Keywords: External Network Modeling, Security Analysis, Optimal Power Flow, Energy Management Systems

14 May 2023 in Energies
Verified
Journal Article
Open access
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KPKonstantinos Plakas
Konstantinos Plakas
IKIoannis Karampinis
Ioannis Karampinis
PAPanayiotis Alefragis
Panayiotis Alefragis
Alexios BirbasAlexios Birbas
Alexios Birbas
MBMichael Birbas
Michael Birbas
APAlex Papalexopoulos
Alex Papalexopoulos
Electricity price forecasting (EPF) has become an essential part of decision-making for energy companies to participate in power markets. As the energy mix becomes more uncertain and stochastic, this process has also become important for industrial companies, as their production schedules are greatly impacted by energy costs. Although various approaches have been tested with varying degrees of success, this study focuses on predicting day-ahead market (DAM) prices in different European markets and how this directly affects the optimal production scheduling for various industrial loads. We propose a fuzzy-based architecture that incorporates the results of two forecasting algorithms; a random forest (RF) and a long short-term memory (LSTM). To enhance the accuracy of the proposed model for a specific country, electricity market data from neighboring countries are also included. The developed DAM price forecaster can then be utilized by energy-intensive industries to optimize their production processes to reduce energy costs and improve energy-efficiency. Specifically, the tool is important for industries with multi-site production facilities in neighboring countries, which could reschedule the production processes depending on the forecasted electricity market price.