Assessment of Economic Surplus Generated at the European Balancing Platforms

Balancing is becoming increasingly coordinated in Europe with the rollout of cross-zonal platforms for the activation of reserve. The European balancing platforms that are being put in place employ zonal network models. The misrepresentation of network constraints in these balancing platforms may cause congestion, which would be challenging to address very close to real time. We propose a hierarchical implementation of nodal balancing which respects the zonal design of European balancing platforms. We illustrate our approach on the classic six-node Chao-Peck example, and discuss the compatibility of our proposal with the institutional requirements of European balancing markets

The energy balance is ensured in the power system with load frequency control (LFC). The frequency is the indicator of the energy balance between active power generation and consumption. To achieve CO2 emission-free power generation, power generation from renewable energy sources (RES) will increase. At the same time, generation from conventional power plants will decrease until they are shut down. As a result, the share of converters without physical inertia will increase. In contrast, the share of running rotating masses will be negligible. To ensure a secure power system, the adjustment of power system operation in the new framework is required. A perspective method for power system operation can be the power system operation with angle-based control. In this paper, a basic comparison of primary control between LFC with Synchronous generator (SG) and angle-based control with voltage source converter (VSC) is made. An RMS simulation is performed for a use case in the 39 bus New England system.

Abstract. Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort to keep snowmelt modeling simple and parsimonious, the Utah Energy Balance (UEB) snowmelt model used only one layer but allowed the snow surface temperature to be different from the snow average temperature by using an equilibrium gradient parameterization based on the surface energy balance. Although this procedure was considered an improvement over the ordinary single layer snowmelt models, it still resulted in discrepancies between modeled and measured snowpack energy contents. In this paper we evaluate the equilibrium gradient approach, the force-restore approach, and a modified force-restore approach when they are integrated as part of a complete energy and mass balance snowmelt model. The force-restore and modified force-restore approaches have not been incorporated into the UEB in early versions, even though Luce and Tartoton have done work in calculating the energy components using these approaches. In addition, we evaluate a scheme for representing the penetration of a refreezing front in cold periods following melt. We introduce a method to adjust effective conductivity to account for the presence of ground near to a shallow snow surface. These parameterizations were tested against data from the Central Sierra Snow Laboratory, CA, Utah State University experimental farm, UT, and subnivean snow laboratory at Niwot Ridge, CO. These tests compare modeled and measured snow surface temperature, snow energy content, snow water equivalent, and snowmelt outflow. We found that with these refinements the model is able to better represent the snowpack energy balance and internal energy content while still retaining a parsimonious one layer format.

了解流域水文过程（水量和水质）是流域综合管理的基础。城市化引起的生态环境问题已成为目前和未来一段相当长的时期内人类社会面临的重大问题。然而，城市化（土地利用/覆被变化、新污染物产生）、水文（降水、入渗、蒸散、径流过程）和生态系统服务（产水服务、调节气候、土壤保持、初级生产力、维持生物多样性等）在不同时空尺度之间的相互作用还存在知识空白。从城市化对流域生态系统结构和功能的影响、城市化对地表能量平衡与水量平衡的影响、城市化对水质和水生生物的影响、以及城市土地利用/覆被变化的大气环境效应等多方面系统总结了城市化影响流域生态水文过程的研究进展。研究发现，城市"热岛"、"干岛"、暴雨径流引起的城市内涝、水污染等环境现象都与生态水文过程密切相关。强调现代城市规划需要遵循生态水文学规律，从全流域生态系统角度认识近年来新出现的不同尺度的城市环境效应。城市最佳管理措施应以流域为单元实施，以调节土地利用/覆被、保护湿地（包括自然与人工湿地）为手段，充分发挥自然生态系统调节功能（如植被蒸散和净化水质）。未来城市生态水文学应围绕"低影响开发"以及"基于自然的解决方案"等城市流域管理措施，在稳定城市小气候、缓解洪涝干旱等极端水文气象灾害风险以及减轻城市水污染等方面开展多尺度综合研究。;Ecohydrology is the most basic science for guiding integrated watershed management. Rapid urbanization permanently alters land cover and the structure and functions of terrestrial ecosystems in a short period of time. Consequently, urbanization affects hydrological processes such as surface evaporation, runoff, and local and regional climate, and ecosystem services (e.g., water supply, carbon sequestration, biodiversity). Urbanization directly affects the physical properties of the near-surface atmosphere, the energy exchange between land and atmosphere, and the water budget of the ecosystems. These changes bring or aggravate a series of water quantity, water quality, and climatic effects, e.g., heat island, dry island, wet island, rain island, and turbid island. This study systematically summarized the research progress in understanding the impacts of urbanization on watershed ecohydrological processes with a focus on the consequences of urbanization on surface energy balance, water balance, water quality and aquatic organisms, and the meteorological effects of urban land use/cover change. The most direct impact of urban land use/cover change on the environment is the alternation of the energy and water balance at multiple scales. The unique physical properties of the urban surface and associated energy balance distribution characteristics are different from natural ecosystems, resulting in unique microclimate and eco-hydrology in an urban environment. Urbanization-driven surface processes have direct or indirect impacts on hydrological processes such as runoff, infiltration, evapotranspiration, groundwater recharge, and river network confluence at different scales by increasing impervious surface and changing vegetation cover conditions. Large-scale urbanization aggravates the peak flow, rainstorm runoff, and annual total water yield as a result of evapotranspiration reduction caused by the significant reduction of vegetation and surface soil infiltration rate. The influence of urbanization on non-point source water pollution is mainly reflected in the change of ‘source’, ‘process’, and ‘sink’ of non-point source pollutants. Urbanization aggravates water quality problems by the increase in impervious surface that elevates pollutant concentration and load and alters physical and chemical processes in aquatic systems. Large-scale conversion of forest lands to urban uses leads to a significant reduction in evapotranspiration, which reduces its ‘biological drainage’ function, coupled with an increase in the impervious surface, and is likely to exacerbate the risk of flooding or the risk of ‘light rainstorms, heavy waterlogging’ phenomena in urban watersheds. The conversions of vegetated ecosystems reduce their ‘air conditioner’ functions and are likely to exacerbate the ‘urban heat island’ and ‘urban dry island’ effects. We summarized measures and strategies centered on ‘Low Impact Development’ to mitigate the urbanization risks through reducing extreme hydrological effects of impervious surface, enhancing the regulating function of natural ecosystems, and implementing the Urban Best Management Practices at a watershed scale. We concluded that future urban ecohydrological science should focus on the studying the mechanisms of ‘Low Impact Development’ and ‘Nature-based Solutions’ in mitigating environmental impacts from the perspectives of water and energy balances and biogeochemical cycling at multiple scales.

This article examines the mechanisms for cross-border interchange of the regulating reserves (RRs), i.e., the imbalance-netting process (INP) and the cross-border activation of the RRs (CBRR). Both mechanisms are an additional service of frequency restoration reserves in the power system and connect different control areas (CAs) via virtual tie-lines to release RRs and reduce balancing energy. The primary objective of the INP is to net the demand for RRs between the cooperating CAs with different signs of interchange power variation. In contrast, the primary objective of the CBRR is to activate the RRs in the cooperating CAs with matching signs of interchange power variation. In this way, the ancillary services market and the European balancing system should be improved. However, both the INP and CBRR include a frequency term and thus impact the frequency response of the cooperating CAs. Therefore, the impact of the simultaneous operation of the INP and CBRR on the load-frequency control (LFC) and performance is comprehensively evaluated with dynamic simulations of a three-CA testing system, which no previous studies investigated before. In addition, a function for correction power adjustment is proposed to prevent the undesirable simultaneous activation of the INP and CBRR. In this way, area control error (ACE) and scheduled control power are decreased since undesired correction is prevented. The dynamic simulations confirmed that the simultaneous operation of the INP and CBRR reduced the balancing energy and decreased the unintended exchange of energy. Consequently, the LFC and performance were improved in this way. However, the impact of the INP and CBRR on the frequency quality has no unambiguous conclusions.

Abstract. Glacier changes are a vivid example of how environmental systems react to a changing climate. Distributed surface mass balance models, which translate the meteorological conditions on glaciers into local melting rates, help to attribute and detect glacier mass and volume responses to changes in the climate drivers. A well-calibrated model is a suitable test bed for sensitivity, detection, and attribution analyses for many scientific applications and often serves as a tool for quantifying the inherent uncertainties. Here, we present the open-source COupled Snowpack and Ice surface energy and mass balance model in PYthon (COSIPY), which provides a flexible and user-friendly framework for modeling distributed snow and glacier mass changes. The model has a modular structure so that the exchange of routines or parameterizations of physical processes is possible with little effort for the user. The framework consists of a computational kernel, which forms the runtime environment and takes care of the initialization, the input–output routines, and the parallelization, as well as the grid and data structures. This structure offers maximum flexibility without having to worry about the internal numerical flow. The adaptive subsurface scheme allows an efficient and fast calculation of the otherwise computationally demanding fundamental equations. The surface energy balance scheme uses established standard parameterizations for radiation as well as for the energy exchange between atmosphere and surface. The schemes are coupled by solving both surface energy balance and subsurface fluxes iteratively such that consistent surface skin temperature is returned at the interface. COSIPY uses a one-dimensional approach limited to the vertical fluxes of energy and matter but neglects any lateral processes. Accordingly, the model can be easily set up in parallel computational environments for calculating both energy balance and climatic surface mass balance of glacier surfaces based on flexible horizontal grids and with varying temporal resolution. The model is made available on a freely accessible site and can be used for non-profit purposes. Scientists are encouraged to actively participate in the extension and improvement of the model code.

The degree to which short‐duration, transient floods modify wetland‐atmosphere exchange of energy, water vapor, and carbon dioxide (CO2) is poorly documented despite the significance of flooding in many wetlands. This study explored the effects of transient floods on salt marsh–atmosphere linkages. Eddy flux, micrometeorological, and other field data collected during two tidal phases (daytime versus nighttime high tides) quantified the salt marsh radiation budget, surface energy balance, and CO2 flux. Analysis contrasted flooded and nonflooded and day and night effects. The salt marsh surface energy balance was similar to that of a heating‐dominated sparse crop during nonflooded periods but similar to that of an evaporative cooling‐dominated, well‐watered grassy lawn during flooding. Observed increases in latent heat flux and decreases in net ecosystem exchange during flooding were proportional to flood depth and duration, with complete CO2 flux suppression occurring above some flood height less than the canopy height. Flood‐induced changes in the salt marsh energy balance were dominated by changes in sensible heat flux, soil heat flux, and surface water heat storage. Parameters suitable for predicting the salt marsh surface energy balance were obtained by calibrating common models (e.g., Penman‐Monteith, Priestley‐Taylor, and pan coefficient). Biophysical controls on salt marsh–atmosphere exchange were identified following calibration of models describing the coupling of canopy photosynthesis and stomatal conductance in the salt marsh. The effects of flooding on salt marsh–atmosphere exchange are temporary but strongly affect the marsh water, carbon, and energy balance despite their short duration.

Atwater Study Plot (ASP), located in the town of Alta, UT in the Wasatch Mountains, which was established in 1939 by Monty Atwater and Ed LaChapelle, is one of the longest running snow observation sites in the Western United States. The historical observations have been primarily snow safety and avalanche forecasting focused. Beginning in 2017 the Snow Hydrology Research to Operations Laboratory (Snow HydRO Lab) at the University of Utah began regular hydrology focused snow pit observations within study plot boundaries. In 2019 the Snow HydRO Lab and the Utah Department of Transportation further supplemented ASP with an instrumentation suite for continuous snow energy and mass balance observations, including incoming and outgoing solar and terrestrial radiation. The goal of the new observations is to support process based hydrologic modelling and better understand controls on snowmelt timing and magnitude. The instrumentation installation and observations make ASP the first snow energy balance study plot in the Wasatch Mountains, and the site has since been used as a validation site for NASA's SnowEx project and is part of the NSF Critical Zone Collaborative Network. Here, we describe the study plot and present (1) the hourly instrumented dataset, which includes standard atmospheric variables (air temperature, relative humidity, and wind speed/direction), radiation balance, precipitation, and snow depth, (2) snow energy balance modelling used to calculate hourly energy exchanges and phase changes, and (3) provide directions to access the publicly available ASP datasets.

The ability to quantify soil–atmosphere water and energy exchange is important in understanding agricultural and natural ecosystems, as well as the earth's climate. We developed a one‐dimensional vertical model that calculates solar radiation, canopy energy balance, surface energy balance, snowpack dynamics, soil water flow, and snow–soil–bedrock heat exchange, including soil water freezing. The processes are loosely coupled (solved sequentially) to limit the computational burden. The model was applied to describe water and energy dynamics for a northeast‐facing mountain slope in the Dry Creek Experimental Watershed near Boise, ID. Calibration was achieved by optimizing the saturated soil hydraulic conductivity. Validation results showed that the model can successfully calculate seasonal dynamics in snow height, soil water content, and soil temperature. Both the calibration and validation years confirmed earlier results that evapotranspiration on the northeast‐facing slope consumes approximately 60% of yearly precipitation, while deep percolation from the soil profile constitutes about 40% of yearly precipitation.

Understanding the Effects of Fires on Surface Evapotranspiration Patterns Using Satellite Remote Sensing in Combination with an Energy Balance Model

Abstract

The share of weather-dependent renewable energy is rising as European power grid balancing markets move toward greater unification. In the Nordics, proactive and automatic balancing using manual Frequency Restoration Reserves was implemented in March 2025, a prerequisite for joining the European balancing platform Manually Activated Reserves Initiative. This paper investigates data from Sweden following its automatic balancing implementation to determine if the challenge of maintaining grid stability correlates with synoptic circulation types. For this study, the challenge of maintaining grid stability is quantified by the absolute error of the imbalance forecast algorithm within the new system. Circulation types are computed using the automatic Jenkinson-Collison classification scheme based on atmospheric surface pressure signals. A regression analysis establishes circulation types as a statistically significant driver of absolute imbalance forecast errors and reveals that balancing is more challenging under cyclonic flows and those originating from the north-westerly quadrant. A control study highlights wind speed as the most dominant underlying parameter. However, accounting for wind speed does not remove all influence of the circulation types, demonstrating that they act as a proxy for complex weather dynamics that affect imbalance forecasting.

If substantial amounts of CO2, which according to actual scenarios may in the future be captured from industrial processes and power generation, shall be utilized effectively, scalable energy efficient technologies will be required. Thus, a survey was performed to assess a large variety of applications utilizing CO2 chemically (e.g., production of synthesis-gas, methanol synthesis), biologically (e.g., CO2 as fertilizer in green houses, production of algae), or physically (enhancement of fossil fuel recovery, use as refrigerant). For each of the processes, material and energy balances were set up. Starting with pure CO2 at standard conditions, expenditure for transport and further process specific treatment were included. Based on these calculations, the avoidance of greenhouse gas emissions by applying the discussed technologies was evaluated. Based on the currently available technologies, applications for enhanced fossil fuel recovery turn out to be most attractive regarding the potential of utilizing large quantities of CO2 (total capacity > 1000 Gt CO2) and producing significant amounts of marketable products on one hand and having good energy and material balances on the other hand $$ \left( {{{t_{CO_2 - emitted} } \mathord{\left/ {\vphantom {{t_{CO_2 - emitted} } {t_{CO_2 - utilized} < 0.2 - 0.4}}} \right. \kern-\nulldelimiterspace} {t_{CO_2 - utilized} < 0.2 - 0.4}}} \right) $$ . Nevertheless, large scale chemical fixation of CO2 providing valuable products like fuels is worth considering, if carbon-free energy sources are used to provide the process energy and H2 being essential as a reactant in a lot of chemical processes (e.g., production of DME: $$ {{t_{CO_2 - emitted} } \mathord{\left/ {\vphantom {{t_{CO_2 - emitted} } {t_{CO_2 - utilized} > 0.34}}} \right. \kern-\nulldelimiterspace} {t_{CO_2 - utilized} > 0.34}} $$ ). Biological processes such as CO2 fixation using micro-algae look attractive as long as energy and CO2 balance are considered. However, the development of effective photo-bioreactors for growing algae with low requirements for footprint area is a challenge.

Balancing services are traded on the balancing market, which has undergone major shifts in recent years due to external factors like the growing share of renewable energies in electricity production and the progressing electrification of society, especially in the mobility sector. This trend increases the demand for balancing services. However, market design is also changing to lower overall expenses for grid stability, which influences price volatility and overall costs for balancing services. Shorter provision times, low capacity limits, and a smaller gap between gate closure time and delivery time enable more flexible market participation of balancing service providers. This article provides an overview of the common European balancing market with a focus on Germany, including recent and upcoming regulatory changes and market design. Recent price trends highlight the importance of market design, especially provision times and price limits. The reduction of the provision time for Frequency Containment Reserve increased offered capacity per bid, and the end of the mixed price procedure in August 2019 led to a less concentrated price range for balancing energy. The introduction of the energy-only market in November 2020 shifted demand from tertiary to secondary control reserve. However, high energy prices in 2021 and 2022 have revealed the limited responsiveness of the balancing energy market. This effect will be reinforced with the exiting of coal-fired and nuclear plants from the pool of balancing service providers in the current decade. Additionally, the future development of the market depends on the integration of energy storage systems such as stationary batteries and electric vehicle batteries, including the regulatory framework.

Information about the energy and water exchanges between the land surface and the lower atmosphere (i.e. land-atmosphere interactions) is necessary for example to improve our understanding of the effect of land-atmosphere interactions on the exacerbation of temperature and precipitation extremes. Observations of energy and water fluxes at the land surface usually rely on the eddy covariance method. There is a wide network of these measurements providing data over all continents but with large spatial gaps in Africa, Asia, South America and Oceania. Additionally, other problems are associated with these observational methods such as the energy and water balance non-closure. To improve the spatial coverage of land-atmosphere interactions data considering the energy and water balance closure, we explore the combination of remote sensing data and a physical-based model. The High resOlution Land Atmosphere Parameters from Space (HOLAPS) framework is a one dimensional modelling framework that solves the energy and water balance at the land surface using remote sensing data and reanalysis products as forcings. Preliminary results from the evaluation ofHOLAPS outputs over Europe at 5 km resolution show an improvement in the simulation of latent heat flux when using remote sensing data in comparison with results using only reanalysis data as forcing. Additionally, we see a moderate improvement in HOLAPS latent heat flux estimates against energy-balance corrected eddy covariance measurements in comparison with other products that solve the energy and water balance equations, such as the ERA5Land product. The new HOLAPS product is available at hourly resolution for the period 2001 to 2016 and these estimates can be useful for agriculture and forest management activities and to evaluate the representation of land-atmosphere feedbacks in weather and climate models.