Publications of Damien Ernst
Bookmark and Share    
Full Text
See detailBlockchain: A novel approach for the consensus algorithm using Condorcet Voting procedure
Vangulick, David ULiege; Cornélusse, Bertrand ULiege; Ernst, Damien ULiege

in Proceedings of the IEEE International Conference on Decentralized Applications and Infrastructures (2019, April)

The blockchain technology allows interested parties to access a common register, the update, and integrity of which are collectively managed in a decentralized manner by a network of actors. It is the ... [more ▼]

The blockchain technology allows interested parties to access a common register, the update, and integrity of which are collectively managed in a decentralized manner by a network of actors. It is the consensus protocol that ensures a common and unambiguous update of transactions by creating blocks of transactions for which integrity, veracity, and consistency are guaranteed through geographically distributed nodes. Bitcoin, the first popular blockchain concept, introduced the Proof of Work consensus based on work validation, and has been extended to thousands of participants. Despite its success and its large use in other crypto-currencies, Proof of Work’s disadvantages are a high latency, a low transaction rate, and a high energy expenditure, making it a less-than-perfect choice for many applications. In addition the validation of transactions is not carried out with a definite temporality. For Bitcoin, it takes on average 10 minutes to create a block. However, for certain use cases such as auctions or the exchange of energy, there is a need for this temporality. The purpose of this article is to propose a new type of consensus that is faster, less energy-consuming and that can be synchronized with a time reference. The core of the reflection is the use of the Condorcet voting mechanism to determine the miner. [less ▲]

Detailed reference viewed: 287 (21 ULiège)
Full Text
See detailVoiture électrique : 697.612 km pour devenir verte ! Vrai ou faux ?
Ernst, Damien ULiege

E-print/Working paper (2019)

Detailed reference viewed: 49 (1 ULiège)
Full Text
See detailElectric car: 697,612 km to become green! True or false?
Ernst, Damien ULiege

E-print/Working paper (2019)

Detailed reference viewed: 69 (2 ULiège)
Full Text
See detailDécret favorisant le développement des communautés d’énergie renouvelable
Ernst, Damien ULiege

Speech/Talk (2019)

Detailed reference viewed: 229 (10 ULiège)
Full Text
See detailOn overfitting and asymptotic bias in batch reinforcement learning with partial observability
François-Lavet, Vincent ULiege; Rabusseau, Guillaume; Pineau, Joelle et al

E-print/Working paper (2019)

This paper provides an analysis of the tradeoff between asymptotic bias (suboptimality with unlimited data) and overfitting (additional suboptimality due to limited data) in the context of reinforcement ... [more ▼]

This paper provides an analysis of the tradeoff between asymptotic bias (suboptimality with unlimited data) and overfitting (additional suboptimality due to limited data) in the context of reinforcement learning with partial observability. Our theoretical analysis formally characterizes that while potentially increasing the asymptotic bias, a smaller state representation decreases the risk of overfitting. This analysis relies on expressing the quality of a state representation by bounding L1 error terms of the associated belief states. Theoretical results are empirically illustrated when the state representation is a truncated history of observations, both on synthetic POMDPs and on a large-scale POMDP in the context of smartgrids, with real-world data. Finally, similarly to known results in the fully observable setting, we also briefly discuss and empirically illustrate how using function approximators and adapting the discount factor may enhance the tradeoff between asymptotic bias and overfitting in the partially observable context. [less ▲]

Detailed reference viewed: 112 (21 ULiège)
Full Text
See detailComplementarity Assessment of South Greenland Katabatic Flows and West Europe Wind Regimes
Radu, David-Constantin ULiege; Berger, Mathias ULiege; Fonteneau, Raphaël ULiege et al

in Energy (2019)

Current global environmental challenges require vigorous and diverse actions in the energy sector. One solution that has recently attracted interest consists in harnessing high-quality variable renewable ... [more ▼]

Current global environmental challenges require vigorous and diverse actions in the energy sector. One solution that has recently attracted interest consists in harnessing high-quality variable renewable energy resources in remote locations, while using transmission links to transport the power to end users. In this context, a comparison of western European and Greenland wind regimes is proposed. By leveraging a regional atmospheric model specifically designed to accurately capture polar phenomena, local climatic features of southern Greenland are identified to be particularly conducive to extensive renewable electricity generation from wind. A methodology to assess how connecting remote locations to major demand centres would benefit the latter from a resource availability standpoint is introduced and applied to the aforementioned Europe-Greenland case study, showing superior and complementary wind generation potential in the considered region of Greenland with respect to selected European sites. [less ▲]

Detailed reference viewed: 430 (60 ULiège)
Full Text
See detailEnergiespecialist Damien Ernst: 'We hoeven helemaal niet minder energie te verbruiken'
Renard, Han; Ernst, Damien ULiege

Article for general public (2019)

Detailed reference viewed: 149 (3 ULiège)
Full Text
See detailIntroducing neuromodulation in deep neural networks to learn adaptive behaviours
Vecoven, Nicolas ULiege; Ernst, Damien ULiege; Wehenkel, Antoine ULiege et al

E-print/Working paper (2019)

In this paper, we propose a new deep neural network architecture, called NMD net, that has been specifically designed to learn adaptive behaviours. This architecture exploits a biological mechanism called ... [more ▼]

In this paper, we propose a new deep neural network architecture, called NMD net, that has been specifically designed to learn adaptive behaviours. This architecture exploits a biological mechanism called neuromodulation that sustains adaptation in biological organisms. This architecture has been introduced in a deep-reinforcement learning architecture for interacting with Markov decision processes in a meta-reinforcement learning setting where the action space is continuous. The deep-reinforcement learning architecture is trained using an advantage actor-critic algorithm. Experiments are carried on several test problems. Results show that the neural network architecture with neuromodulation provides significantly better results than state-of-the-art recurrent neural networks which do not exploit this mechanism. [less ▲]

Detailed reference viewed: 67 (21 ULiège)
Full Text
See detailA Deep Reinforcement Learning Framework for Continuous Intraday Market Bidding
Boukas, Ioannis ULiege; Ernst, Damien ULiege; Théate, Thibaut ULiege et al

E-print/Working paper (2019)

Detailed reference viewed: 108 (20 ULiège)
Full Text
See detailSimulation-based Assessment of the Impact of Regulatory Frameworks on the Interactions between Electricity Users and Distribution System Operator
Manuel de Villena Millan, Miguel ULiege; Ernst, Damien ULiege; Gautier, Axel ULiege et al

E-print/Working paper (2019)

This paper proposes a simulation-based methodology for evaluating the effectiveness of various regulatory frameworks promoting the large-scale deployment of decentralised electricity generation resources ... [more ▼]

This paper proposes a simulation-based methodology for evaluating the effectiveness of various regulatory frameworks promoting the large-scale deployment of decentralised electricity generation resources (DERs) in distribution systems. Electricity consumers, prosumers, and the distribution system operator (DSO) are modelled as agents interacting with each other in an artificial environment which encapsulates the salient features of realistic regulatory frameworks, along with a set of assumptions on DER technology availability, performance, and costs. More precisely, the methodology enables to simulate the interactions between those agents in a great variety of environments in order to study the progressive deployment of DER as a function of its profitability, and also shows how this deployment impacts the remuneration mechanism of the DSO and the evolution of the distribution tariff. The methodology is illustrated on a case study considering 16 different regulatory environments and using data for Belgian DSOs. [less ▲]

Detailed reference viewed: 81 (13 ULiège)
Full Text
See detailEvaluating the Evolution of Distribution Networks under Different Regulatory Frameworks with Multi-Agent Modelling
Manuel de Villena Millan, Miguel ULiege; Fonteneau, Raphaël ULiege; Gautier, Axel ULiege et al

E-print/Working paper (2019)

In the context of increasing decentralised electricity generation, this paper evaluates the effect of different regulatory frameworks on the evolution of distribution networks. This problem is addressed ... [more ▼]

In the context of increasing decentralised electricity generation, this paper evaluates the effect of different regulatory frameworks on the evolution of distribution networks. This problem is addressed by means of agent based modelling in which the interactions between the agents of a distribution network, and an environment are described. The consumers and the distribution system operator are the agents, which act in an environment that is composed by a set of rules. For a given environment, we can simulate the evolution of the distribution network by computing the actions of the agents at every time step of a discrete time dynamical system. We assume the electricity consumers are rational agents that may deploy distributed energy installations. The deployment of such installations may alter the remuneration mechanism of the distribution system operator. By modelling this mechanism, we may compute the evolution of the electricity distribution tariff in response to the deployment of distributed generation. [less ▲]

Detailed reference viewed: 39 (14 ULiège)
Full Text
See detailImpact of gate closure time on the efficiency of power systems balancing
Petitet, Marie; Perrot, Marie; Mathieu, Sébastien ULiege et al

in Energy Policy (2019), 129

This paper focuses on market design options for operational balancing management in self-dispatch electric power systems. In particular, it investigates the most relevant timing for the balancing gate ... [more ▼]

This paper focuses on market design options for operational balancing management in self-dispatch electric power systems. In particular, it investigates the most relevant timing for the balancing gate closure, when competitors' decisions on the setting of controllable assets are neutralized and this responsibility is simultaneously transferred to the system operator. This discussion is central in the development and implementation of the European Electricity Balancing Guideline. Based on a multi-level simulation tool with a realistic modelling of short-term power system operations, this paper proposes the first quantitative assessment of postponing the balancing gate closure time from 1 h to 15 min ahead of the imbalance settlement period. For different environments (energy mix, power plant capabilities, outages, etc), the results highlight that postponing the balancing gate closure time from 1 h to 15 min increases the operational cost of the system. Based on robust and scalable results, we show that this difference is mainly due to a better coordination of the available resources by the central decision maker. [less ▲]

Detailed reference viewed: 136 (4 ULiège)
Full Text
See detailGovernments at COP24 should focus on building a global electricity grid – Prof. Damien Ernst
Gillman, Steve; Ernst, Damien ULiege

Article for general public (2018)

Detailed reference viewed: 103 (12 ULiège)
Full Text
See detailCritical Time Windows for Renewable Resource Complementarity Assessment
Berger, Mathias ULiege; Radu, David-Constantin ULiege; Fonteneau, Raphaël ULiege et al

E-print/Working paper (2018)

This paper proposes a systematic framework to assess the complementarity of renewable resources over arbitrary geographical scopes and temporal scales which is particularly well-suited to exploit very ... [more ▼]

This paper proposes a systematic framework to assess the complementarity of renewable resources over arbitrary geographical scopes and temporal scales which is particularly well-suited to exploit very large data sets of climatological data. The concept of critical time windows is introduced, and a spatio-temporal criticality indicator is proposed, consisting in a parametrised family of scalar indicators quantifying the complementarity between renewable resources in both space and time. The criticality indicator is leveraged to devise a family of optimisation problems identifying sets of locations with maximum complementarity under arbitrary geographical deployment constraints. The applicability of the framework is shown in a case study investigating the complementarity between the wind regimes in continental western Europe and southern Greenland, and its usefulness in a power system planning context is demonstrated. Besides showing that the occurrence of low wind power production events can be significantly reduced on a regional scale by exploiting diversity in local wind patterns, results highlight the fact that aggregating wind power production sites located on different continents may result in a lower occurrence of system-wide low wind power production events and indicate potential benefits of intercontinental electrical interconnections. [less ▲]

Detailed reference viewed: 791 (47 ULiège)
Full Text
See detailReinforcement learning, energy systems and deep neural nets
Ernst, Damien ULiege

Speech/Talk (2018)

Detailed reference viewed: 46 (2 ULiège)
Full Text
See detailFostering Share&Charge through proper regulation
Vanrykel, Fanny ULiege; Ernst, Damien ULiege; Bourgeois, Marc ULiege

in Competition and Regulation in Network Industries (2018)

This article studies the emergence of Share&Charge, a German platform that organizes the sharing of charging stations for electric vehicles (EVs) and the billing for the energy transactions. Share&Charge ... [more ▼]

This article studies the emergence of Share&Charge, a German platform that organizes the sharing of charging stations for electric vehicles (EVs) and the billing for the energy transactions. Share&Charge follows a peer-to-peer fashion, enabling direct transactions between charging station owners and EV drivers. On the demand side, the platform, with its interactive map, makes it possible for EV owners to find a charging station in the most suitable location, for instance, at their place of work or where they live. On the offer side, Share&Charge enables station operators (private individuals or companies) to rent their charging stations and eventually to sell the electricity they produce. Charging tariffs within the charging station network are determined by the charging station operators themselves, but the platform provides indicative tariffs. Launched in September 2017, Share&Charge follows other initiatives, such as the French platforms Wattpop and ChargeMap, and the Swedish Elbnb. Share&Charge’s network is already proven to be successful with German citizens. Share&Charge adds certain elements of value at different stages of EV utilization. First, this model allows for a co-financing of charging infrastructures by individuals and businesses in the private sector by sharing the infrastructure costs among EV drivers. Besides the purchase price of EVs, the implementation of charging infrastructures and their financing represent a significant barrier to the rise of e-mobility. Share&Charge helps remove this obstacle without adding a further burden on the governmental budget. In addition, this approach follows the ‘‘user pays principle,’’ which engages in fair and effective financing. Second, the platform increases decentralized production value and facilitates its expansion. It also helps in avoiding grid congestion and energy loss, as well as increasing flexibility within the electricity market. Third, data use enables the optimization of energy demand and supply, and the optimal determination of tariffs, although these remain facultative. Models like Share&Charge could thus positively impact energy policy by tackling several upcoming obstacles associated with the development of EVs and decentralized energy production capacities. However, new forms of network structures (decentralized networks, sharing economy) and new actors (prosumers, platforms, etc.) also raise regulatory challenges. This article presents some of the legal issues associated with the development of models like Share&Charge. In particular, we study the tax framework applicable to this model, assuming that as such, it would be introduced into the Belgian market. [less ▲]

Detailed reference viewed: 110 (5 ULiège)
Full Text
See detailCentralised Planning of National Integrated Energy System with Power-to-Gas and Gas Storages
Berger, Mathias ULiege; Radu, David-Constantin ULiege; Fonteneau, Raphaël ULiege et al

in Proceedings of the 11th Mediterranean Conference on Power Generation, Transmission, Distribution and Energy Conversion (Medpower2018) (2018, November)

This paper proposes an optimisation-based framework to tackle long-term centralised planning problems of integrated energy systems with bi-directional electricity-gas carriers coupling under various ... [more ▼]

This paper proposes an optimisation-based framework to tackle long-term centralised planning problems of integrated energy systems with bi-directional electricity-gas carriers coupling under various policy constraints. The framework is leveraged to gain insight into possible configurations of the future Belgian energy system, and identify the cost-optimal energy mix as well as short and long-term storage requirements to satisfy CO2 emissions reductions and energy security targets. Results shed light on the economics of a transition to a low-carbon energy system and reveal the potential of power-to-gas and storage in gas form to help achieve ambitious emissions reduction goals. [less ▲]

Detailed reference viewed: 733 (36 ULiège)