French Electricity Research Articles

French economy and clean energy transition: A macroeconomic multi-objective extended input-output analysis

The complexity of a sustainable economy is rooted in its socio-economic and environmental intricacies, particularly in formulating pathways for the harmonious integration of these parameters. This study introduces an extended input-output analysis and a multi-objective optimisation framework designed to discern trajectories for reducing CO2 emissions while simultaneously maximising GDP and employment. The economic alterations are evaluated through metrics facilitating the examination of both direct and indirect consequences stemming from perturbations within the economy. The focus of this research centres on the French economy, concentrating on pivotal sectors where reducing demand could yield the greatest reduction in CO2 emissions with minimal socio-economic ramifications. Additionally, a model is outlined for energy substitution, wherein fossil fuels in the French electricity mix are supplanted with clean energies. The ensuing effects of such a model on emission reduction pathways are scrutinised, followed by a comparison with the baseline case study.

Second-best electricity pricing in France: Effectiveness of existing rates in evolving power markets

The adoption of time-varying pricing in the French electricity market has been historically low despite their availability to consumers well before the deployment of smart metering. However, as the share of variable renewable electricity increases and carbon prices grow, the demand-side response will become increasingly important to achieve efficiency gains. Relying on the historical hourly consumption of French electricity consumers and multiple prospective weather years, we study the gain allowed by the broader adoption of time-varying electricity retail rates in low-carbon power systems. We develop a four-stage methodology to assess the efficiency and stability of the electricity supply cost component of the electricity bill in France for historical and prospective years. Our analysis demonstrates that peak pricing schemes have increasing interest in the context of further deployment of renewable capacity, capturing 25% to 50% of the welfare gain reached by real-time pricing schemes. The corresponding deadweight loss of peak pricing schemes represents 0.4 to 1 bn EUR per year in 2030 compared to real-time prices (RTP) schemes. Conversely, deadweight loss of current time-of-use (ToU) rates represents 1 to 1.2 bn EUR per year in 2025 and increases over time. The current design of TOU rates does not provide adequate incentives in future power systems. Besides the tariff efficiency, the results underlined an increasing price difference between on-peak and off-peak rates. This questions the social acceptance of time-varying retail rates for consumers unable to hedge against peak prices. By analysing the effectiveness and limitations of time-varying rates, our findings underline the importance and value of price-based DR in future power systems in general. Our results highlight the need to revise the end-user tariff design in the French power system, notably with regard to the conveyed price signals.

Unsupervised separation of the thermosensitive contribution in the power consumption at a country scale

A large part of French electricity consumption variation is due to temperature fluctuations. While HVAC (heating, ventilation and air-conditioning) systems consumption are directly affected by the temperature, other systems (refrigerator, freezer, water heater) can also be driven by weather changes making thermal contribution to overall consumption difficult to extract. This paper presents a “by-design” unsupervised data-driven method to separate the consumptions due to the weather in the overall electricity consumption. The proposed deep-learning model is based on the separation of meteorological parameters from calendar ones within the model architecture. The performances of this model, in particular its ability to split consumption mechanisms, is tested on a synthetic dataset and on the french consumption dataset. Being relatively simple and interpretable, this approach can be generalized to other countries whereasenergy sobriety represents an important challenge we are facing.

Optimal sizing and energy management of a microgrid: A joint MILP approach for minimization of energy cost and carbon emission

The optimal design and operation of microgrids involves complex trade-offs between technical, economic, and environmental factors. This research addresses these challenges by proposing a comprehensive approach that combines the sizing and energy management problems of a microgrid into a single decision-making framework. The study introduces a joint multi-objective mixed-integer linear programming algorithm that minimizes the levelized cost of energy (LCOE) and life cycle emissions (LCE) of the microgrid formed by photovoltaic system, battery storage, and with/without grid connections. By considering 25-year project lifetime horizon and hourly energy management, the algorithm ensures an optimal solution that accounts for long-term planning and real-time operation. The research conducts an analysis of French electricity grid as a case study where a Pareto-front is created using the trade-off constraint approach. Furthermore, the impact of peak shaving is assessed on Pareto-front for various subscription power to utility grid. Lastly, the research examines energy sources in the French electricity grid, revealing insights into the energy mix’s implications for microgrid design. The results showed that LCOE and LCE can vary up to 28% and 17%, respectively, while the local renewable energy utilization can be increased to 54% by limiting the grid subscription power at 36 kVA.

Environmental impacts of a digital health and well-being service in elderly living schemes

Over the past decade, digitalization and digital technologies (DTs) have undergone rapid evolution, transforming how goods and services are produced and consumed in modern societies. Health and well-being sectors have embraced this digital revolution. Besides the economic and social benefits, digitalization can significantly enhance patient diagnostics and prognostics while improving overall service efficiency. To ensure long-term sustainability, it is important to assess and reduce the environmental impacts of digital services. This article examines the life cycle impacts of a digital service implemented in three elderly living schemes (ELSs) located in the United Kingdom (UK). The digital service consists of six electronic devices (EDs) that enable communication between residents, visitors, staff, and offsite monitoring (OM). The equipment is connected using Power over Ethernet (PoE) technology, which includes smart network switch and uninterruptable power supply units. The digital service's global warming potential (GWP) was estimated at 718–741 kg CO2 eq./resident for two of the ELSs and 1509 kg CO2 eq./resident for a third ELS, considering a service period of 20 years. The reason for the significant difference is the greater use of air conditioner (A/C) units to cool down server rooms and fewer residents in the third scheme. The consumption of electricity was found to be the main contributor to most of the environmental impacts. However, in certain categories such as mineral resource scarcity, freshwater eutrophication, and freshwater and marine ecotoxicity potentials, printed circuit boards (PCBs) were the main contributors. A sensitivity analysis considering different national electricity mixes demonstrated that the French electricity grid promoted the reduction in 14 impact categories, whereas the German, Italian, Spanish and Japanese grids increased on average impacts on most categories. Another sensitivity analysis demonstrates that reducing A/C unit running time by 28% resulted in an average impact reduction of 5.5%, becoming equivalent to the results obtained for the French electricity grid. Finally, extending the expected lifespan of electronic equipment by 20% yielded the highest average decrease in environmental impacts (8.1%). While digitalization has the potential to enhance patient healthcare and reduce costs, it is crucial to carefully assess its environmental impacts and implement mitigation strategies to ensure sustainable development in the healthcare sector.

Reform of the European electricity market: Should we prefer a price based on a weighted average of marginal costs with cross-subsidies?

On the wholesale electricity market, the equilibrium price is set each hour on the basis of the marginal cost of the last power plant called, which is a gas-fired power plant a large part of the time in Europe. The surge in gas prices since the end of 2021 therefore largely explains the rise in the price of electricity. This paper analyses the reform projects proposed within the European Union to curb this surge in wholesale prices. It proposes then to reform the system by opting for pricing based on the weighted average hourly marginal costs, with financial compensation for power plants whose marginal cost is higher than this average. The quantitative study is conducted over the period January 1, 2020 through December 31, 2022 using ENTSOE hourly data. By implementing a compensation framework founded on average marginal costs, the market price experiences a significant decline, resulting in typically negative residual profits. Consequently, the fixed costs associated with the power plant fleet necessitate funding through the capacity market. This approach would enable French electricity consumers to align their payments with the structure of the national electricity fleet, specifically reflecting the average costs of power stations characterized by substantial fixed costs, such as nuclear facilities. The adoption of this proposed system is poised to expedite the energy transition toward a low-carbon economy.

“When things aren't going well at home and at work, it is hard”: What can companies do about domestic violence?

Domestic violence has considerable professional repercussions. Abusive partners isolate victims, damage their self-confidence, belittle them, instill doubt, and create an atmosphere of uncertainty and fear. Such mechanisms of domination, control, and isolation could have consequences for the professional lives of the victims, including absenteeism, decreased performance, and errors. These professional consequences can further isolate the victims because organizational actors, often unaware of or not understanding the domestic violence the victims are experiencing, can hold them accountable for poor work outcomes. This paper reports on action research conducted at EDF, a large French electricity company, and sheds light on the role of the employer in supporting victims of domestic violence, particularly by proposing a set of social and human resources practices that could help the victims escape from abusive situations. However, while it is important for organizations to undertake initiatives in addressing the cases of domestic violence, such involvement remains voluntary and depends on the goodwill of employing organizations. That is what some labor unions wish to change by advocating new professional rights for victims of domestic violence at national levels.

Learning Data-Driven Stable Corrections of Dynamical Systems—Application to the Simulation of the Top-Oil Temperature Evolution of a Power Transformer

Many engineering systems can be described by using differential models whose solutions, generally obtained after discretization, can exhibit a noticeable deviation with respect to the response of the physical systems that those models are expected to represent. In those circumstances, one possibility consists of enriching the model in order to reproduce the physical system behavior. The present paper considers a dynamical system and proposes enriching the model solution by learning the dynamical model of the gap between the system response and the model-based prediction while ensuring that the time integration of the learned model remains stable. The proposed methodology was applied in the simulation of the top-oil temperature evolution of a power transformer, for which experimental data provided by the RTE, the French electricity transmission system operator, were used to construct the model enrichment with the hybrid rationale, ensuring more accurate predictions.

Cross-border Effects between the Spanish and French Electricity Markets: Asymmetric Dynamics and Benefits in the Light of European Market Integration

We investigate cross-border dynamics between the Spanish and French electricity markets in the light of EU’s market integration. The analysis is highly relevant given the isolation of the Iberian Peninsula from the rest of European markets and its unique electricity market design. Results show the shift in the merit order curve in each market. Electricity prices in Spain follow the dynamics of the French ones, fostered by Spain’s import-dependence. Benefits of grid integration are asymmetric, with Spanish users taking advantage of the market integration with France. The substitution effect between domestic fuel-based units and imported green electricity allows Spain to further decarbonize its energy mix and increase the security of supply. The expansion of the cross-border grid until 2030 will be key for a successful phasing out of the remaining coal-based units. Our findings should be considered in support schemes for integration projects to align the incentives of participants.

Estimation of the general population and children under five years of age in France exposed to magnetic field from high or very high voltage power line using geographic information system and extrapolated field data

BackgroundThe effects of extremely low-frequency magnetic fields, especially their long-term health effects, including childhood leukaemia, remain elusive. The International Agency for Research on Cancer has classified the exposure to magnetic fields >0.4 μT as ‘possibly carcinogenic to humans (group 2 B)’ for childhood leukaemia. However, the number of exposed individuals, particularly children, remains poorly documented in international literature. The objective of this study was to estimate the number of individuals living near a high or very high voltage line in France (≥63 kV), among the general population and children under the age of five years. MethodsThe estimate considered different exposure scenarios depending on the line voltage and the distance of the housing from it, and whether the line is overhead or underground. The exposure scenarios were obtained using a multilevel linear model created from a measurement database published by “Réseau de transport d'électricité”, the operator of the French electricity transmission network. ResultsBetween 0.11% (n = 67,893) and 1.01% (n = 647,569) of the French population and between 0.10% (n = 4712) and 1.03% (n = 46,950) of children under five years of age were estimated to be living in an area potentially exposed to a magnetic field, depending on the exposure scenario (>0.4 μT and >0.1 μT, respectively). ConclusionsBy making it possible to estimate the total number of residents, schools, and health institutions near high-voltage power lines, the proposed methodology can help identify potential co-exposures near high-voltage power lines, which are regularly cited as a possible explanation for contradictory results from epidemiological studies.

A construção social como meio da intervenção ergonômica

Abstract Although Ergonomic Workplace Analysis (EWA) practice is common in Brazil, some critics have asserted that it is not sufficient to bring about an effective change of the workplace. Although this criticism may be partly admissible in regard to Brazilian ergonomics, it cannot be considered to apply to France, where Activity-Centered Ergonomics was born. At the same time, it is important to not confuse EWA with the broader field of Activity-Centered Ergonomics. Against this background, this article seeks to analyze the elements that characterize contemporary ergonomics practices in Brazil so as to compare them to the modes of intervention developed in France. We also seek to investigate models, concepts and methods so as to expand the possibilities of ergonomic interventions in Brazil. To do so, we will start from a theoretical examination of the development of EWA in Brazil from its origins in France, presenting an intervention conducted at a French electricity company. Next, we will discuss the losses suffered by EWA during the transfer of EWA methodology from France to Brazil, as well as the need to cultivate social construction at all stages of these interventions. We conclude by showing the importance of developing this debate in the field of ergonomics and the need to continue it.

Ring the alarm! Electricity markets, renewables, and the pandemic

The pandemic’s impacts on European electricity markets have been enormous, especially in countries with abundant low marginal costs of production like France. This article provides an in-depth quantitative study of the impacts of the crisis on the French electricity sector. During the first lockdown episode, France has experienced unparalleled reductions of electricity demand (−12%) and wholesale prices (−45%) resulting in gross revenue losses of 1.3 billion € (−47%) for market participants. This paper argues that the observed market outcomes during the crisis are somehow indicative of outcomes in a future with abundant renewable power, where prices will fall in a more sustainable way.

Techno-economic relevance of absorption chillers to enhance existing 3GDH

This article studies the economical, technical and environmental aspects of a third generation district heating (DH) network with absorption chillers installed at substation level in order to satisfy the cooling demands. This network solution hence takes advantage of the distribution facilities of existing DH systems. The study aims at evaluating the technical and environmental performances of this new district heating architecture, when sized and operated according to an economic objective using the Mixed Integer Linear Programming (MILP) optimization formalism. It is compared to the case where cooling demands are met using individual chillers.The paper first presents the production, distribution, demand and storage models. Regarding the demand side, different heating and cooling scenarios are studied by varying the proportions of residential and tertiary buildings. The model is fed in a second part with data from the French context. In particular, we rely on typical French weather conditions, thermal loads and energy costs.The analysis of the results focuses on the cooling part. It appears that the thermal network solution achieves on average a 3.6% reduction in the levelized cost of space cooling energy. In the worst case space cooling exergy efficiency goes through a 82% decrease. GHG emissions decrease on average by 7.7% thanks to the absence of leakage of refrigerant with high global warming potential. Overall, these emissions are low due to the low carbon content of French electricity.

Combining Dantzig-Wolfe and Benders decompositions to solve a large-scale nuclear outage planning problem

Optimizing nuclear unit outages is of significant economic importance for the French electricity company EDF, as these outages induce a substitute production by other more expensive means to fulfill electricity demand. This problem is quite challenging given the specific operating constraints of nuclear units, the stochasticity of both the demand and non-nuclear units availability, and the scale of the instances. To tackle these difficulties we use a combined decomposition approach. The operating constraints of the nuclear units are built into a Dantzig-Wolfe pricing subproblem whose solutions define the columns of a demand covering formulation. The scenarios of demand and non-nuclear units availability are handled in a Benders decomposition. Our approach is shown to scale up to the real-life instances of the French nuclear fleet.

Applying Harmonised Geothermal Life Cycle Assessment Guidelines to the Rittershoffen Geothermal Heat Plant

Heat production from a geothermal energy source is gaining increasing attention due to its potential contribution to the decarbonization of the European energy sector. Obtaining representative results of the environmental performances of geothermal systems and comparing them with other renewables is of utmost importance in order to ensure an effective energy transition as targeted by Europe. This work presents the outputs of a Life Cycle Assessment (LCA) performed on the Rittershoffen geothermal heat plant applying guidelines that were developed within the H2020 GEOENVI project. The production of 1 kWhth from the Rittershoffen heat plant was compared to the heat produced from natural gas in Europe. Geothermal heat production performed better than the average heat production in climate change and resource use, fossil categories. The LCA identified the electricity consumption during the operation and maintenance phase as a hot spot for several impact categories. A prospective scenario analysis was therefore performed to assess the evolution of the environmental performances of the Rittershoffen heat plant associated with the future French electricity mixes. The increase of renewable energy shares in the future French electricity mix caused the impact on specific categories (e.g., land use and mineral and metals resource depletion) to grow over the years. However, an overall reduction of the environmental impacts of the Rittershoffen heat plant was observed.

Techno-Economic Assessment and Life Cycle Assessment of CO2 to Biofuel via Micro-Algae Process

The goal of the work is to assess economic and environmental performance of microalgal biofuel production chain and identify hotspots in terms of CAPEX/OPEX, GHG emissions, energy demand and other environmental impacts. These evaluations are used to assist future R&D and business development directions. The modelled plant has a production capacity of 163 kt-biofuels/year (corresponding to 1 Mta-CO2/year treatment capacity by microalgae). Operational energy demand is around 0.17 MJ/MJ of biofuel. Techno-economic assessment shows that future biofuel production cost would be down to 1190 €/t. It is suggested to focus future R&D on cultivation, HTL and upgrading operations, as well as equipment design of cultivation. Life cycle assessment shows that a GHG emissions reduction of 72% would be reached by micro-algae biofuel, compared to conventional fuel in French electricity mix scenario. When looking into all environmental impacts, there is a trade-off when switching to microalgae-based biofuel, and trade-off seems acceptable. It is suggested to focus future R&D on heat integration of HTL/upgrading, reduction of nutrients and flocculent or research of alternative chemicals with lower environmental impact. Use of affordable blue or green hydrogen would further reduce environmental impacts as well.

Low-carbon options for the French power sector: What role for renewables, nuclear energy and carbon capture and storage?

In the wake of the Paris agreement, France has set a target of zero net greenhouse gas emissions by 2050. This target can only be achieved by rapidly decreasing the proportion of fossil fuels and accelerating the deployment of low-carbon technologies. We develop a detailed model of the power sector to investigate the role of different low- and negative-emission technologies in the French electricity mix and we identify the impact of the relative cost of these technologies for various values of the social cost of carbon (SCC). We show that for a wide range of SCC values (from 0 to €500/tCO2), the optimal power mix consists of roughly 75% of renewable power. For a SCC value of €100/tCO2, the power sector becomes nearly carbon neutral while for €200/tCO2 and more it provides negative emissions. The availability of negative emission technologies can decrease the system cost by up to 18% and can create up to 20MtCO2/year of negative emissions, while the availability of new nuclear power stations is much less important. This study demonstrates the importance of an effective SCC value (as a tax for positive emissions and remuneration for negative emissions) in reaching carbon neutrality at moderate cost. Negative emissions may represent an important carbon market which could attract investments if supported by public policies.

Downscaling of future national capacity scenarios of the French electricity system to the regional level

In order to respond to the COP21 targets in terms of carbon mitigation, the participant governments have set pledges and roadmaps for renewable energy penetration in order to decarbonize the different energy sectors (electricity, transport, industry, etc.). This paper raises the question of the regional distribution of the targeted renewable capacities and their precise locations across twelve regions in France. To do so, land and ocean eligibility for renewable penetration is studied taking into account the different environmental, techno-economic, social and political criteria constraining the implementation of renewable generation facilities. Onshore and offshore wind as well as solar photovoltaics (open field) are investigated. The maximum integration capacities are then evaluated for each region in France, and total 306, 33, and 1,626 GW respectively. According to a review of French capacity scenarios from in the literature, these potentials are clearly far beyond the renewable capacities suggested for 2035. Therefore, the eligible spots for renewable integration are subjected to a multi-criteria analysis in order to select the most propitious spots in response to the suggested capacities.

Grid operation-based outage maintenance planning

The increasing integration of renewable energies in the French electricity network leads to important changes in its operation, resulting in new grid constraints. Besides, some maintenance tasks on the overhead power lines are live-line works, and others require a planned outage. Such interruptions may not be feasible with a renewables-driven grid operation. As a consequence, current maintenance planning methods might not be relevant in the future. In particular, they have to take into account the risk implied by performing maintenance when having a high proportion of renewables in the grid. This work presents a three-step approach for tackling this issue. First, risk values corresponding to different future scenarios are computed, using the (N-1) security assessment. Second, these computed values are included in several optimisation approaches in order to find a good schedule. Eventually, a third step validates the obtained planning.

Economic assessment of high renewable energy penetration scenario in 2030 on the interconnected Irish power system

The Irish Government has set very ambitious targets for the penetration of renewables into the Integrated Single Electricity Market (I-SEM), aiming for 40% electricity generation by 2020. This renewable share is expected to increase further in the I-SEM, British Electricity Trading and Transmission Arrangements (BETTA) and French electricity market by 2030. This research presents a case study testing the various levels of renewable energy integration in the three regions and assessed the economic impacts and benefits at elevated renewables penetration. To measure the economic and environmental sustainability, four indicators, i.e. annual wholesale system marginal prices (SMPs), total generation costs, total generation net revenues and CO2 emissions were selected. The results showed that the I-SEM 2030 wholesale electricity market pricing would range from €101.26/MWh to €50.77/MWh with the increase of renewable integration from 44% to 75%. In the BETTA and French market, the addition of the renewable generation contributes to reductions to SMPs by 51.10% and 51.61% at most, respectively. It was also found that these enhanced renewable targets for 2030 could lower consumers’ electricity bills and expand the total social welfare.