European Energy System Research Articles

Hydrogen sourcing strategies and cross-sectoral flexibility trade-offs in net-neutral energy scenarios for Europe

Achieving climate neutrality in Europe requires transformations in all parts of the economy, including the power, building, industry, and transport sector. Given the necessary direct and indirect electrification measures, flexibility potentials and sourcing strategies for renewable energy carriers increasingly become the centre of attention. With a pan-European cross-sectoral capacity expansion planning framework, this case study investigates the trade-offs and impacts resulting from different realisations of heat, transport, and industry flexibility sources in future net-neutral scenarios against the background of two hydrogen sourcing strategies for Europe. Assessments of individual and combined effects analyse multiple combinations of realised or unrealised sector-specific flexibility characteristics, including a no- and full-flexibility scenario. This approach quantifies the value of a fully sector-integrated European energy system and its dependency on hydrogen and e-fuel imports from outside of Europe for a less flexible system. It further shows the heterogeneous nature and country-specific constitution of low-carbon power and energy markets to play an important role for market values of generation and consumption technologies. In general, the analysis highlights the need for explicitly representing hybrid sector interfaces with significant technological and temporal detail in low-carbon energy systems.

Multicriteria decision support for the evaluation of electricity supply resilience: Exploration of interacting criteria

The resilience of an energy system and especially the national electricity supply is a complex and multidimensional concept, which is receiving growing attention at a European level. In particular, the increasing risks of extended electricity supply disruptions and/or severe electricity price fluctuations are stressing the need for an assessment of the European countries’ electricity supply resilience. This paper proposes an elaborative multicriteria decision support methodological framework, based on three major resilience dimensions, namely: “resist”, “restabilise” and “recover”. In total, 35 European countries are evaluated and ranked according to their performance on 17 interacting evaluation criteria. The overall evaluation of the countries is established based on a synergy of two complementary multicriteria decision aid (MCDA) methods. Specifically, the Choquet Integral is approached and assessed as an importance indicator to properly accommodate and incorporate the interacting criteria into the value system, negating therefore their arbitrary effects on the final benchmarking. Simultaneously, a procedure based on the Simos method supports the robust elicitation of the Choquet capacities. All preferential information required for the implementation of the MCDA framework has been elicited from an expert, highly knowledgeable of the European energy system. This research work aims to support energy policymakers in Europe and provide guidelines and areas for improvement at a country level.

Application of a Stochastic Multicriteria Acceptability Analysis to support decision-making within a macro-scale energy model: Case study of the electrification of the road European transport sector

Energy system models based on the TIMES framework can explore possible energy futures through the construction of a network of technological processes, to satisfy a set of exogenously imposed service demands at the least-cost system configuration. This work presents a methodology aimed at supporting decision-makers in finding optimal energy-system configuration in a complex energy environment, characterized by uncertain information. First, the EUROfusion TIMES Model is used to assess the sensitivity of different long-term evolutions of the European energy system, with particular reference to the road transport sector, considering different trends for the prescribed future variations of investment cost and vehicle efficiency. In a second step, the Stochastic Multicriteria Acceptability Analysis is used to critically evaluate the alternative optimal configurations proposed by the model simulations under a set of economic and environmental criteria. The results of the analysis allow the discussion of the influence of such criteria on the different alternative cases, complementing the cost minimization approach. In the case study considered here, high penetrations of electric vehicles in the road fleet are favored by economic, environmental and energy-related priorities.

Assessing the value of demand response in a decarbonized energy system – A large-scale model application

This paper presents extensive insights on the value of applying demand response (DR) in a system perspective against the background of two strongly contrasting decarbonization pathways for a decentralized and centralized European energy system with a 100% renewable share and sector coupling. The pathways are characterized by structural differences concerning the combination of installed renewable capacities, the acceptance for activated demand response potentials and different electricity, heat and hydrogen demands. The objective is to determine the potential role of demand response and its impact on the optimal combinations of flexibility options in a decentralized vs. centralized scenario framework model-endogenously. Therefore, openly available data and hourly time series of country-specific demand response potentials are implemented into a large-scale linear optimization model. Sensitivities concerning varying shares of demand response availability are used to identify main influencing factors on selected components of the electricity system such as the capacity and generation mix, storage requirements, renewable integration and their market value factors, CO2 emissions and total system costs. Model results show a higher reduction of total system costs and CO2 emissions per activated demand response unit in the photovoltaic dominated decentralized scenario (–55 MEUR/GWDR, –0.045 MtCO2/GWDR), compared to the wind dominated centralized scenario (–39 MEUR/GWDR, –0.037 MtCO2/GWDR). The outcomes conclude that the daily photovoltaic feed-in characteristics have a higher correlation with the time pattern of load shifting and shedding demand response appliances than wind feed-in characteristics.

The role of demand response in the future renewable northern European energy system

Increasing demand response (DR) from households, industry and tertiary sector may provide substantial flexibility in renewable-based energy systems, but the deployment of DR is currently limited. This study examines the future economic potential DR in the renewable rich northern European region, and also analyses power markets impacts of large-scale DR deployment in the region. For the quantifications, the energy system model BALMOREL is used, modified to include a detailed temporal modelling of available DR potentials. Results show that among the DR options analysed, space heating and water heating provide the highest shares of loads shifted. The overall demand response potential is particularly high in Norway and Sweden, due to wide-spread electric space- and water heating. Low variable costs make these DR applications economically feasible for deployment, despite high supply-side flexibility provided by regulated hydro power. DR may contribute to peak shaving of up to 18.6% of total peak load in 2050. Revenues from DR-application yield very different results depending on techno-economic parameters, potentials and the price volatility in the various analysed market areas. Results show an insignificant change in CO2 emissions between scenarios with and without demand response.

CO2 mitigation or removal: The optimal uses of biomass in energy system decarbonization

SummaryOwing to its versatility, biomass can be used for a range of CO2 mitigation and removal options. The recent adoption of end-of-century temperature targets at the global scale, along with mid-century economy-wide net zero emission targets in Europe, has boosted demand forecasts for this valuable resource. Given the limited nature of sustainable biomass supply, it is important to understand most efficient uses of biomass, both in terms of avoided CO2 emissions (i.e., substituted energy and economic services) and CO2 removal. Here, we quantify the mitigation and removal potential of key bio-based CO2 removal pathways for the transport, power, construction, and iron and steel sectors in Europe. By combining the carbon balance of these pathways with their economics, the optimal use of biomass in terms of CO2 avoidance and removal costs is quantified, and how these evolve with the decarbonization of the European energy system is discussed.

Biomass from Winery Waste: Evaluation of Dust Explosion Hazards

Food and drink supply chains have significant environmental impacts due to their use of resources, emissions, and waste production. An efficient method to reduce this impact is the valorisation of biomass waste through energy recovery by using it as a source of heat. The European energy system faces several fundamental challenges being currently the largest emitter of greenhouse gases due to its large dependence on fossil fuels (mostly natural gas). Therefore, the energy sector's decarbonization will play a central role in achieving a climate-neutral economy in Europe. Identifying the suitable material for biofuel is basically focused on the amount of energy that the material stores, availability, and logistic considerations. Sawdust and wood chips have been extensively used as biofuel in recent years, but other promising raw and waste materials could be adopted (with the positive effect of reducing the impact on forestry soil and the food chain). Novel materials bring consequently novel challenges, also regarding their safe use. As an example, a relevant waste flow is produced from wine manufacturing. A solid with high moisture content is obtained from grapes pressing, and it could be reused to produce distillates. The obtained exhausted pomace could be considered among the materials potentially involved in energy recovery. It is also carrying dust explosion hazard, as solid residues could be present in the form of coarse and fine powders.In this work, grape pomace is examined: its explosion safety-related properties are evaluated to define the severity of events in which this material could be ignited. Minimum Ignition Energy (MIE), explosion pressure peak (Pmax), deflagration severity index (KSt), autoignition temperature (MIT), and Volatile Point (VP) are measured according to standard procedures. This material's thermal susceptibility and ignition sensitivity are studied and compared with biomasses from different sources (ligneo-cellulosic and herbaceous).

Comparing CO2 emissions impacts of electricity storage across applications and energy systems

Summary Electricity storage systems can support the decarbonization of energy systems. However, the effect of electricity storage use on greenhouse gas emissions is complex because of roundtrip efficiency losses of the storage and its effects on the dispatch of different electricity-generation technologies. The limited literature examining this issue focus on individual electricity storage applications and the geographies where they are applied. Here, we systematically compare the effects of electricity storage on CO2 emissions across four applications in electricity systems resembling seven European countries. Our findings reveal large emission impact differences between applications and countries. Among other findings, we find that when compared with wholesale arbitrage, storing electricity in other applications exhibits much lower effects on CO2 emissions. We also investigate different policy options to reduce CO2 emissions from storing electricity. We find that although a higher carbon price can have a substantial effect on reducing the CO2 emissions from wholesale arbitrage, other applications require alternative approaches.

Mitigating heat demand peaks in buildings in a highly renewable European energy system

Space and water heating accounts for about 40% of final energy consumption in the European Union and thus plays a key role in reducing overall costs and greenhouse gas emissions. Many scenarios to reach net-zero emissions in buildings rely on electrification, but meeting the heat demand peaks in the winter can be challenging, particularly when wind and solar resources are low. This paper examines how to mitigate space heating demand peaks most cost-effectively in a top-down, sector-coupled model with carbon dioxide emissions constraint to be net-zero. It introduces the first model that co-optimises both supply and efficiency simultaneously including all European countries with hourly resolution. The competition between technologies to address these heating peaks, namely building retrofitting, thermal energy storage and individual hybrid heat pumps with backup gas boilers is examined. A novel thought experiment demonstrates that the level of building renovation is driven by the strong seasonal heat peaks, rather than the overall energy consumption. If all three instruments are applied, total costs are reduced by up to 17%. Building renovation enables the largest benefit with cost savings of up to 14% and allows individual gas boilers to be removed from the energy system without significant higher costs.

Power-to-Ships: Future electricity and hydrogen demands for shipping on the Atlantic coast of Europe in 2050

The Atlantic coast of Europe has very high demand for maritime transport, with important commercial ports and tourist areas that emit significant amounts of greenhouse gas emissions. In an effort to address this, the impact of electric and H2 ships for freight and passenger transport along the Atlantic coast on the European energy system in 2050 is analyzed. An optimized energy supply model is applied, which envisions a cost-optimal infrastructure with 100% renewable energy across all of Europe, employing hydrogen as an energy vector. To achieve this target, a minimization of the total annual costs to supply electricity and hydrogen demands is carried out. The obtained results indicate that Ireland will play a key role as a hydrogen supplier as ship demand rises, increasing onshore and electrolyzer capacities, mainly due to comparable low-cost renewable electricity production. The preferred supply routes for Irish hydrogen will be pipelines through the United Kingdom and France to export energy to continental Europe. An increase in salt cavern storage capacity in the United Kingdom, central Europe and Spain is observed. H2 and electricity are shown to be essential for the deployment of more sustainable maritime transport and related activities on the European Atlantic coast.

Intrinsic kinetics in local modelling of thermochemical heat storage systems

Abstract Thermochemical heat storage is expected to play an important role in the ongoing transformation of the European energy system. The efficiency of thermochemical heat storage systems largely depends on that of the reactor, since it limits the amount of the heat stored per unit volume as well as the rate of the heat recovery. Thus, the optimization of the reactor design is of great importance and can be achieved via local numerical modelling, where intrinsic parameters of the materials are utilized. In the present study, we developed a procedure for the determination of the intrinsic kinetic parameters of ammonia sorption on metal halides and applied it to strontium chloride SrCl2 – ammonia NH3 working pair. A distinctive feature of the procedure is that the kinetic measurements were performed on a Sieverts type apparatus at constant temperature, which allowed resolving the common problem of heat-up time. Besides, the kinetic measurements were carried out using the optimal mass of SrCl2 – expanded natural graphite composite material (70 mg of SrCl2), ensuring that the chemical reaction rate is not constrained by the heat and mass transfer limitations. As a result, the intrinsic kinetic equations of NH3 sorption on SrCl2 ammines were derived for the first time and were demonstrated to predict the experimental data, from which they had been computed, over a wide pressure–temperature range. In addition, the obtained intrinsic kinetics, as well as the ones found in literature, were implemented in a three-dimensional numerical model computing the local temperature, pressure, and reaction advancement through the coupled equations of the heat transfer, fluid dynamics, and chemical reaction rate. The numerical results were compared with experimental data obtained on 466 mg of SrCl2 powder at various pressure–temperature conditions. In contrast to the literature kinetics, the simulation results with the intrinsic kinetic equations were found to be in a good agreement with the experimental data, demonstrating the importance of using intrinsic parameters in the local modelling of sorption reactions.

Erratum to: Development and modelling of different decarbonization scenarios of the European energy system until 2050 as a contribution to achieving the ambitious 1.5 ∘C climate target—establishment of open source/data modelling in the European H2020 project openENTRANCE

Erratum to: Development and modelling of different decarbonization scenarios of the European energy system until 2050 as a contribution to achieving the ambitious 1.5 ∘C climate target—establishment of open source/data modelling in the European H2020 project openENTRANCE

Does ‘more’ equal ‘better’? – Analyzing the impact of diversification strategies on infrastructure in the European gas market

The paper investigates investments in gas infrastructure considering uncertainties in European gas markets. Furthermore, the study addresses the question of whether (more) diversification provides a (better) security of supply improvement. Thus, a stochastic optimization approach is introduced. The uncertainties focus on 2030 and 2045 in three dimensions, namely the Ukraine gas transit, future LNG prices, and the expected gas demand. Considering three diversification strategies, the model GAMAMOD-EU.sto optimizes investments in pipelines, LNG import terminals and gas storages as well as the gas dispatch. Results illustrate trade-offs between optimal gas supply and diversification strategies. Investments in pipelines to North African suppliers are made across all strategies, while the building of the Nord Stream 2 pipeline depend on the respective diversification strategy. Diversification through LNG quota changes the dispatch results significantly. Investments in storages are almost not necessary over all strategies, however, storages provide flexibility to prevent supply shortages, when diversification strategies are applied. Conclusion for policy makers regarding what is needed for preventing malinvestments and high costs in the European gas market are: an enhanced relationship between Russia and the EU and a clear vision on the role of gas in the future European energy system that reduces demand uncertainty.

The role of 4th generation district heating (4GDH) in a highly electrified hydropower dominated energy system

District heating (DH) is considered an important component in a future highly renewable European energy system. With the turn towards developing 4th generation district heating (4GDH), the integral role of district heating in fully renewable energy systems is emphasized further. Norway is a country that is expected to play a significant role in the transition of the European energy system due to its high shares of flexible hydropower in the electricity sector. While the country is moving towards electrification in all sectors and higher shares of variable renewable electricity generation, district heating could potentially decrease the need for electric generation and grid capacity expansion and increase the flexibility of the system. In this paper we investigate the role of 4GDH in a highly electrified future Norwegian energy system. A highly electrified scenario for the Norwegian energy system is constructed based on a step-by-step approach, implementing measures towards electrification and expansion of renewable electricity generation. Then, a 4GDH scenario is constructed for the purpose of analysing the role of 4GDH in a highly electrified hydropower based energy system. EnergyPLAN is used for simulation. Results show that an expansion of 4GDH will increase the total system efficiency of the Norwegian energy system. However, the positive effects are only seen in relation to the introduction of efficiency measures such as heat savings, more efficient heating solutions and integration of low-temperature excess heat. Implementation of heat savings and highly efficient heat pumps in individual based heating systems show a similar effect, but does not allow for excess heat integration. In the modelled DH scenario, the introduction of large heat storages has no influence on the operation of the energy system, due to the logic behind the EnergyPLAN model and the national energy system analysis approach chosen, and thus the effect of implementing 4GDH may be underestimated.

To Prevent or Promote Grid Expansion? Analyzing the Future Role of Power Transmission in the European Energy System

Future energy supply systems must become more flexible than they are today to accommodate the significant contributions expected from intermittent renewable power sources. Although numerous studies on planning flexibility options have emerged over the last few years, the uncertainties related to model-based studies have left the literature lacking a proper understanding of the investment strategy needed to ensure robust power grid expansion. To address this issue, we focus herein on two important aspects of these uncertainties: the first is the relevance of various social preferences for the use of certain technologies, and the second is how the available approaches affect the flexibility options for power transmission in energy system models. To address these uncertainties, we analyze a host of scenarios. We use an energy system optimization model to plan the transition of Europe’s energy system. In addition to interacting with the heating and transport sectors, the model integrates power flows in three different ways: as a transport model, as a direct current power flow model, and as a linearized alternating current power flow model based on profiles of power transfer distribution factors. The results show that deploying transmission systems contribute significantly to system adequacy. If investments in new power transmission infrastructure are restricted—for example, because of social opposition—additional power generation and storage technologies are an alternative option to reach the necessary level of adequacy at 2% greater system costs. The share of power transmission in total system costs remains widely stable around 1.5%, even if cost assumptions or the approaches for modeling power flows are varied. Thus, the results indicate the importance of promoting investments in infrastructure projects that support pan-European power transmission. However, a wide range of possibilities exists to put this strategy into practice.

Robust design of a future 100% renewable european energy supply system with hydrogen infrastructure

Variable renewable energy sources (VRES) will be the cornerstones of future energy supply systems. Nevertheless, their inherent intermittency remains an obstacle to their widespread deployment. Renewably-produced or ‘green’ hydrogen has been suggested as an energy carrier that could account for this in a sustainable manner. In this study, a fully VRES-based European energy system in the year 2050 is designed using an iterative minimal cost-optimization approach that ensures robust supply security across 38 weather-year scenarios (1980–2017). The impact of different power generation locations is factored in by defining exclusive VRES groups within each optimization region. From this, it can be seen that higher numbers of groups in each region offer cheaper electricity generation locations to the optimizer and thus decrease the system's total annual costs. Furthermore, the robust system design and impact of inter-annual variability is identified by iteratively combining the installed capacities of different system designs derived through the application of the 38 historical weather years. The system design outlined here has significantly lower capacities in comparison to the maximum regional capacities obtained in the first round of optimization.

Modelling uncertainty in coupled electricity and gas systems—Is it worth the effort?

The interdependence of electricity and natural gas markets is becoming a major topic in energy research. Integrated energy models are used to assist decision-making for businesses and policymakers addressing challenges of energy transition and climate change. The analysis of complex energy systems requires large-scale models, which are based on extensive databases, intertemporal dynamics and a multitude of decision variables. Integrating such energy system models results in increased system complexity. This complexity poses a challenge for energy modellers to address multiple uncertainties that affect both markets. Stochastic optimisation approaches enable an adequate consideration of uncertainties in investment and operation planning; however, stochastic modelling of integrated large-scale energy systems further scales the level of complexity. In this paper, we combine integrated and stochastic optimisation problems and parametrise our model for European electricity and gas markets. We analyse and compare the impact of uncertain input parameters, such as gas and electricity demand, renewable energy capacities and fuel and CO2 prices, on the quality of the solution obtained in the integrated optimisation problem. Our results quantify the value of encoding uncertainty as a part of a model. While the methodological contribution should be of interest for energy modellers, our findings are relevant for industry experts and stakeholders with an empirical interest in the European energy system.

Alternative energy imaginaries: Implications for energy research, policy integration and the transformation of energy systems

The paper highlights shortcomings in the contribution of qualitative social sciences and humanities (SSH) research to tackling challenges connected with energy and climate change. These shortcomings are illustrated based on analysis of data gathered in relation to EU (e.g. Horizon 2020; FP7) and European national research funding and energy policy. The paper finds that a techno-economic energy imaginary continues to dominate European energy systems and governs expectations of energy research and its conduct, the integration of SSH with energy policy-making and the framing and foci of policy. A more nuanced, context-sensitive approach is presented as an alternative ‘practices and cultural change’ energy imaginary. This emphasises attention to social practices relevant to energy use, interdisciplinarity and the coproduction of knowledge with diverse actors. Adoption of such an imaginary can help to enhance policy integration of SSH and the contribution of SSH to ameliorating energy and climate change challenges while providing insight into why gaps occur between (supra)national energy policy and local practices.

The Influence of Large-Scale Wind Farm Wake Losses and Sector Coupling on the Development of Offshore Grids

Offshore grids can have a key role in the transition of the energy system to sustainability. Although they require extensive infrastructure investments, they open up for the exploitation of additional resources and may be important to provide for part of the increasing electricity demand driven by sector coupling. This paper quantifies the socio-economic value of offshore grids and identifies their major drivers, performing energy system optimization in a model application of the Northern-central European energy system and the North Sea offshore grid towards 2050. The increasing wake loss with the size of hub-connected wind farms is integrated in the modelling. We find that without sector coupling no offshore grid may develop, and that the higher the level of sector coupling, the higher the value of offshore grids. Considering the influence of increasing wake losses with the size of hub-connected wind farms is especially relevant with higher level of sector coupling, leading to a more spread distribution of hub-connected wind farms, and to an improved representation of the available wind generation in the hubs. Therefore, it can be strongly stated that offshore grid infrastructure development should not be discussed as a separate political topic, but seen in connection to sector coupling.

MARKET MECHANISM FORMATION FOR STIMULATING THE DEVELOPMENT OF ENERGY ACCUMULATION SYSTEMS IN UKRAINE

development of energy storage systems. The current state of energy storage systems in Ukraine is studied. The capacity of the segment of energy storage systems in the energy market, due to the need to meet the requirements of the European Energy Community on the flexibility of the integrated energy system, renewable energy sources and the objective need to use such systems as system service providers. The sufficiency of market and state incentives for the broad application and development of energy storage technologies in the conditions of quasi-competitive and full-scale electricity market of Ukraine is determined, taking into account the perspective tendencies of energy development. The cost and benefit analysis of investment projects for installation and operation of energy storage systems for three most common and prospective types of applications for the Ukrainian electricity market: participation in the market of ancillary system services, participation in the balancing market and system constraints reduction (renewables) is conducted. The sensitivity of project indicators of these types of applications is analyzed depending on the number of parameters: variations in specific capital expenditures, green tariff rates, market prices "day ahead" and market conditions of system services. It is substantiated that in Ukraine the energy storage systems are the most promising as the providers of system services for primary regulation of frequency and power, a sufficient reserve of which is one of the conditions for integration of the Ukrainian power system into the European energy system ENTSO-E, ancillary services through auctions for the provision of primary regulation services with a long-term time horizon. Regarding the prospects for the development of decentralized energy system, it is proved that the development of decentralized storage systems consisting of industrial facilities, substations and other low-capacity energy facilities has great potential with reformatting the energy system architecture to "smart grid" standards to form fundamentally new economic incentives for the development of energy storage systems.