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Wind Task 51 and PVPS task 16: How large-scale weather pattern influence short-term solar forecast error?
No full textInternational audienceAccurate intraday solar forecasts are crucial for electricity trading and microgrid management. While satellitebased methods outperform numerical weather prediction (NWP) models for short-term horizons, their accuracy depends heavily on stable weather conditions, performing poorly during convection, fog, or large depressions. This study investigates the impact of various North Atlantic weather regimes-Atlantic Ridge, Scandinavian Blocking, NAO+, and NAO--on the reliability of satellite-based forecasts.We conducted an 8-year backtest using forecasts generated four hours ahead with a 15-minute time step and validated them against pyranometer data. Our analysis shows that forecast errors vary significantly with the prevailing weather regime. The difference in relative RMSE between the Scandinavian Blocking and Atlantic Ridge regimes was 10-12% in summer (2016-2020) and approximately 10% after 2020. In winter, this difference was around 20% before 2020 and 15% after 2020. These findings demonstrate that large-scale atmospheric patterns significantly influence forecast reliability. Given that weather regimes can be predicted in advance, this analysis provides valuable insights for anticipating forecast error, which can help optimize PV integration and serve as a useful input for machine-learning-based forecast algorithms. These variations in weather regime frequencies directly impact forecast errors, emphasizing the importance of large-scale atmospheric patterns in solar energy forecast reliability. As weather regimes can be predicted several days in advance, this analysis provides useful information to anticipate the magnitude of forecast error and therefore adapt suitable decisions for optimizing PV integration management and electricity trading and provide important insights to develop deep learning forecast algorithms
The Unemployment‐Risk Channel in Business‐Cycle Fluctuations
No full textInternational audienceThe unemployment‐risk channel (URC) amplifies an initial contraction through a reduction in consumption demand by workers who fear unemployment. Crucial for this are the dynamics of job separations and firm hiring. In US data, the job‐finding rate responds slower to identified macroeconomic shocks than the separation rate, but accounts for a similar share of the unemployment response. We calibrate a tractable heterogeneous‐agent new‐Keynesian model with endogenous separations and sluggish vacancy creation to match these facts. The share of output fluctuations due to the URC is twice as large as in a standard model with exogenous separations and free entry
Scalar turbulent fluxes and variances in the interfacial layer from lidar observations and assessment of Lagrangian Stochastic Models
No full textInternational audienceThe link between scalar second‐order moments and gradient in the interfacial layer (IL) capping the convective boundary layer (CBL) is analysed using new lidar turbulent‐scale observations. Temperature and moisture variances as well as sensible and latent heat fluxes have been measured during 100 hours in CBL temperate and arid regions with various free‐cloud meteorological conditions. The IL fluxes and variances have been confronted with Lagrangian Stochastic Model (LSM) theories using scalar gradients, vertical velocity variance, kinetic energy dissipation rate and integral scales of turbulence with the purpose to build a local parametrization. The results show that a Pearson diffusion model in a stratified flow, that relies on the IL vertical velocity variance, and buoyant oscillation period, and 1 as the critical scale of turbulent diffusion, gives universal relevant parameters for IL temperature and moisture flux and variance. Our observations enable to infer for the first time IL local scaling for temperature, and moisture eddy diffusivities. The LSM local scaling parameters have been compared successfully for temperature with previous large‐eddy simulations and with in‐situ observations made in the nocturnal stratified atmospheric surface layer. Other LSM tested in this work that uses different scales to characterize IL scalar statistics, failed, especially for moisture statistics
Informing the uninformed, sensitizing the informed: The two sides of consumer environmental awareness
No full textInternational audienceHow do environmental information and awareness interact to improve environmental quality by changing consumer behavior and firm strategies? This article provides theoretical insights using an original differentiation model within a general framework whose specific cases have been studied previously. On the demand side, only informed consumers differentiate brown from green product quality, while uninformed consumers consider these perfect substitutes. Moreover, all informed consumers value the green product and devalue the brown product due to an aversion effect but are heterogeneous in their environmental awareness. On the supply side, two firms offer different environmental qualities and compete on price. We consider two types of environmental campaigns: increasing the number of informed consumers and increasing the environmental awareness of informed consumers. We show that these campaigns crucially determine three market configurations: segmented; fragmented, with a brown product that appeals to both uninformed consumers and a fraction of informed consumers; and covered. Assuming that the greenest consumer behavior is abstention, we find that a situation where all consumers are informed and some are highly environmentally aware is not necessarily the greenest. Depending on the aversion effect, the campaign organizer’s budget, and their relative cost-effectiveness, information and awareness-raising campaigns require a judicious mix
Avis du conseil scientifique du comité de bassin Seine-Normandie sur la sobriété en eau
No full textThere is often a confusion between sufficiency, efficiency, recycling, and substitution. One response to water shortages during droughts is often to mobilize other water resources, ranging from interconnecting drinking water networks to reusing unconventional water, including storage and inter-basin transfers. These responses do not lead to a reduction in dependencies. Water savings are mainly achieved through technical means (increased efficiency). This is a minimal adaptation of production and consumption patterns (Barles, 2024), which can have negative externalities, exacerbated by trends related to climate change and resource depletion. sufficiency differs from reduction/economy in principle: it involves organizing collectively and culturally to adapt production and water consumption patterns to meet needs within the limits of planetary resources. sufficiency increases resilience to inevitable shocks, reduces costs and enhances competitiveness (by avoiding waste and unnecessary investment in infrastructure), and facilitates the achievement of objectives in terms of reducing greenhouse gas emissions and pollution, and safeguarding biodiversity. Achieving sufficiency requires: o training and information; o involvement from all sectors, particularly energy production, raw material extraction, and agricultural production; o participatory governance and long-term planning: the unfair nature of certain sharing decisions leads to unsustainable practices; o local consultation on the allocation of extractable volumes involving all relevant stakeholders.La confusion est très fréquente entre sobriété, efficacité, recyclage et substitution. Une réponse aux pénuries d’eau lors des sécheresses est souvent la mobilisation d’autres ressources en eau, ce qui va de l’interconnexion des réseaux d’eau potable, à la réutilisation d’eaux non conventionnelles, en passant par le stockage, jusqu’aux transferts interbassins. Ces réponses ne conduisent pas à une réduction des dépendances. Les économies d’eau sont principalement obtenues par des moyens techniques (augmentation de l’efficacité). Il s’agit là d’une adaptation a minima des modes de production et de consommation (Barles, 2024), qui peuvent avoir des externalités négatives, aggravées par des tendances liées au changement climatique et à l’épuisement des ressources. La sobriété se distingue de la réduction/l’économie, dans son principe : il s’agit de s’organiser collectivement et culturellement pour adapter les modes de production et la consommation en eau à la satisfaction des besoins dans les limites des ressources planétaires. La sobriété permet d’augmenter la résilience aux chocs inévitables, de réduire les coûts et renforcer la compétitivité (en évitant le gaspillage et les investissements inutiles dans des infrastructures), de faciliter l’atteinte des objectifs en termes de réduction des émissions de gaz à effet de serre, des pollutions, et de sauvegarde de la biodiversité. Atteindre la sobriété nécessite : o de la formation et de l’information ;o une implication de tous les secteurs, en particulier la production d'énergie ; l’extraction de matières premières et la production agricole ; o des gouvernances participatives et une planification à long terme : le caractère inéquitable de certaines décisions de partage conduit à des pratiques non sobres ;o une concertation locale sur l’allocation des volumes prélevables impliquant l’ensemble des acteurs concernés
Games in Product Form for Demand Response Modelling
No full textEnergy systems are changing rapidly. More and more, energy production is becoming decentralized, highly variable and intermittent (solar, wind), while demand is diversifying (electric vehicles). As a result, balancing supply and demand is becoming more complex, making the adjustment of demand an interesting tool. Demand response is a typical leader-follower problem: a consumer (follower) adjusts his energy consumption based on the prices (or any other incentive) set by the supplier (leader). We propose a versatile and modular framework to address any leader-follower problem, focusing on the handling of often overlooked informational issues. First, we introduce a model that defines the rules of the game (W-model): agents are decision-makers, and Nature encapsulates everything beyond their control, such as private knowledge and exogenous factors. Following the so-called Witsenhausen intrinsic model, we present an efficient way to represent - on a product set, equipped with a product σ-algebra - the information available to agents when making decisions. Next, we introduce Games in Product Form (W-games) by equipping each player (a group of agents) with preferences (objective function and belief) over different outcomes. Thereby, we incorporate an additional layer of information, the characteristics of the preferences linked to players, which affects the possible definitions of an equilibrium. We make this explicit in Nash and Stackelberg equilibria. Equipped with this framework, we reformulate several papers on demand response, highlighting overlooked informational issues. We also provide an application based on the Thailand demand response program
Across land, sea, and mountains: sulphate aerosol sources and transport dynamics over the northern Apennines
No full textInternational audienceIn this study, we combine aerosol observations with high-resolution Eulerian (WRF-CHIMERE) and Lagrangian (FLEXPART) modelling to investigate the source regions, emission sources, transport pathways, and chemical transformation of sulphate aerosols at the high-altitude Monte Cimone station during July 2017. Our analysis shows that marine air masses are linked to higher levels of sulphate at Monte Cimone. In particular, the sea plays a dominant role in enhancing the oxidation of sulphur dioxide (SO2) into sulphate due to prolonged exposure to elevated hydroxyl radical (OH) concentrations over the sea. At the same time, sensitivity simulations reveal that industrial emissions contribute significantly to sulphate levels at Monte Cimone, even when air masses have spent a long time travelling over the sea. Furthermore, examination of vertical atmospheric dynamics indicates that free tropospheric air masses favour higher concentrations of sulphuric acid likely due to lower condensation sink (CS) conditions in the free troposphere (FT). In contrast, boundary layer conditions were found to enhance the transport of dimethyl sulphide (DMS) oxidation products, meaning that, over the Mediterranean Sea, DMS and its oxidation products do not reach the FT efficiently. Our results highlight the complex interaction between marine and terrestrial sources, atmospheric chemistry, and transport mechanisms in shaping sulphate aerosol levels at high-altitude sites. They also provide valuable insights into sulphate sources and transport processes over large geographical area
Take-up of Social Benefits: Experimental Evidence from France
No full textInternational audienceWe report on two nationwide experiments with job seekers in France. We first show that a meeting with social services to assess eligibility and help with applications to social benefits increased new benefit take-up by 29 percent. By contrast, an online simulator that gave personalized information on benefit eligibility did not increase take-up. Marginal treatment effects show that individuals who benefit the most from the meetings are the least likely to attend. Overall, without ruling out information frictions, our results suggest that transaction costs represent the main obstacle to applying for benefits or accessing government’s assistance in applying
Enhancing public understanding of extreme weather events in a changing climate through ClimaMeter
No full textInternational audienceClimaMeter is a real-time platform designed to provide rapid, science-based assessments of extreme weather events and their links to climate change. ClimaMeter's methodology relies on identifying large-scale atmospheric circulation patterns and comparing them to historical data, analysing how the intensity of extreme weather events have changed because of anthropogenic climate change or natural climate variability. By leveraging historical climate data, machine learning, and real-time weather observations, ClimaMeter delivers near-instantaneous attribution results, enabling informed decision-making in a time when media cycles and public attention are brief. This speed is crucial for climate action, as it helps policymakers, emergency responders, and the public understand the role of climate change in specific extreme events and take timely, effective measures. This allows for quicker, data-driven responses to disasters, such as the 2023 French heatwave and Storm Poly, by informing disaster response, infrastructure planning, and resilience-building efforts. ClimaMeter also plays a key role in countering climate change misinformation, offering clear, evidence-based explanations to the public and media. By bridging the gap between scientific research and policy applications, ClimaMeter supports climate action, promotes public awareness, and aids in the development of adaptation and mitigation strategies to address the growing risks posed by climate change
Reproblematising maintenance, reconsidering infrastructures: The emergence of a more-than-corrective maintenance programme in French water networks management
No full textInternational audienceIn an increasing number of countries, mainly but not restrictively in the global North, the combination of infrastructures’ degradation, budgetary constraints and rising environmental issues has gradually shifted professional and public concerns from extension to upkeep. This constitutes the crystallisation of a specific configuration of infrastructure management, which the authors propose to term an “age of infrastructure maintenance” and which contrasts dramatically with the modern infrastructural ideal. Focussing on French water network management, this paper draws on an 18-month in-depth institutional ethnography to investigate what this age of maintenance concretely encompasses. It shows that in France, and in Europe, such an age rests on a reproblematisation of maintenance, whose scope is reframed in a “more-than-corrective” perspective. This leads to a practical and ontological reconsideration of infrastructures, which is illustrated by three main transformations: infrastructures are rediscovered through proximal enquiries, they are carefully monitored as living entities, and they are put at the centre of new valuation processes. This specific moment of infrastructure maintenance appears to be generative, opening up multifaceted transformations that pave the way for a less modernist and industrial vision of infrastructure management