European Power System Research Articles

Characterizing the winter meteorological drivers of the European electricity system using targeted circulation types

AbstractRenewable electricity is a key enabling step in the decarbonization of energy. Europe is at the forefront of renewable deployment and this has dramatically increased the weather sensitivity of the continent's power systems. Despite the importance of weather to energy systems, and widespread interest from both academia and industry, the meteorological drivers of European power systems remain difficult to identify and are poorly understood. The present study presents a new and generally applicable approach, targeted circulation types (TCTs). In contrast to standard meteorological weather‐regime or circulation‐typing schemes, TCTs convolve the weather sensitivity of an impacted system of interest (in this case, the electricity system) with the intrinsic structures of the atmospheric circulation to identify its meteorological drivers. A new 38 year reconstruction of daily electricity demand and renewable supply across Europe is used to identify the winter large‐scale circulation patterns of most interest to the European electricity grid. TCTs provide greater explanatory power for power system variability and extremes compared with standard meteorological typing. Two new pairs of atmospheric patterns are highlighted, both of which have marked and extensive impacts on the European power system. The first pair resembles the meridional surface pressure dipole of the North Atlantic Oscillation (NAO), but shifted eastward into Europe and noticeably strengthened, while the second pair is weaker and corresponds to surface pressure anomalies over Central Southern and Eastern Europe. While these gross qualitative patterns are robust features of the present European power systems, the detailed circulation structures are strongly affected by the amount and location of renewables installed.

Planning and operating a renewable-dominated European power system under uncertainty

In this paper we study the European power system for 2050 from both the expansion and the operation perspectives. First, the generating and storage capacity to be built is decided by solving a multi-stage investment model taking into account the uncertainty related to the investment costs and the demand growth. Stochastic programming is used to represent this decision-making problem under uncertainty. Second, the daily operation of the resulting European power system is analyzed. A two-stage stochastic-programming problem is proposed to model the day-ahead energy and reserve markets in the first stage, and the real-time operation in the second stage. At this level, the uncertainty of the hourly available wind and solar power and the demand level is considered. The numerical results indicate that an European power system mainly based on solar and onshore wind power is possible at a reasonable cost if storage units are also installed. The total new generating capacity to be built up to 2050 will be around 881 GW, which leads to an investment cost of at least 1622 billion euros. The possibility of wind, solar and storage units to provide a certain reserve capacity allows to reduce the participation of thermal units. Therefore, a 77% reduction in the CO2 emissions respect to 1990 may be achieved in 2050. Finally, unserved demand is found in few countries only in 75 h of the year, while the average daily energy prices are stable and comparatively low among the countries.

A multi-objective approach to the prospective development of the European power system by 2050

This paper reports the recent work carried out to engage both the environmental impact and the economic indicators on the prioritisation of dispatchable technologies in the European energy mix up to 2050. Those two contradictory indicators are incorporated in a multi-criteria optimisation leading to iterations of two scenario: business as usual and 2 °C climate policy. The results present the evolution of the climate change emission versus the operational costs of the power system up to 2050. The yearly electricity mix evaluations allow assessing the long-term development of the European energy system, where a focus is done on variable renewable energy production. It is shown that policy-only solutions, associated with a traditional cost-oriented optimisation, have a limited impact on helping the power sector to reach emission levels targets. Integrating the objective of reducing emissions to the management of power plants would reduce the absolute and cumulative carbon dioxide equivalent emissions. The counterpart is that the system electricity price tends to increase faster thus implying increased social costs.

Towards a sustainable European energy system: Linking optimization models with multi-regional input-output analysis

The European Union set ambitious goals regarding renewable energy and greenhouse gas (GHG) emissions. This study uses two models to analyze the implications of these goals on the European energy system and on the rest of the world, based on several scenarios for the mid and long term. First, using a linear programming optimization model for capacity expansion and unit commitment, we obtain the optimal design of the European power system in 2030 and 2050. Results for Germany are then used as input in a Multi-Regional Input-Output Analysis with the objective of analyzing the environmental and socioeconomic effects derived from the new energy system. The linking of both models in each scenario is at the core of this study. Results show the capabilities of this method in terms of GHG emissions, cumulative energy demand, value added, and job creation.

Analyzing Demand Response in a Dynamic Capacity Expansion Model for the European Power Market

One of the challenges in the transition towards a zero-emission power system in Europe will be to achieve an efficient and reliable operation with a high share of intermittent generation. The objective of this paper is to analyse the role that Demand Response (DR) potentially can play in a cost-efficient development until 2050. The benefits of DR consist of integrating renewable source generation and reducing peak load consumption, leading to a reduction in generation, transmission, and storage capacity investments. The capabilities of DR are implemented in the European Model for Power Investments with high shares of Renewable Energy (EMPIRE), which is an electricity sector model for long-term capacity and transmission expansion. The model uses a multi-horizon stochastic approach including operational uncertainty with hourly resolution and multiple investment periods in the long-term. DR is modelled through several classes of shiftable and curtailable loads in residential, commercial, and industrial sectors, including flexibility periods, operational costs, losses, and endogenous DR investments, for 31 European countries. Results of the case study shows that DR capacity partially substitutes flexible supply-side capacity from peak gas plants and battery storage, through enabling more solar PV generation. A European DR capacity at 91 GW in 2050 reduces the peak plant capacities by 11% and storage capacity by 86%.

Reserve procurement and flexibility services in power systems with high renewable capacity: Effects of integration on different market designs

This paper investigates different reserve issues inspired by the European situation, focusing on both the moment when reserves are procured and the degree of coordination among Transmission System Operators (TSOs) in that procurement. We present three scheduling models formulated as stochastic programs that represent the day-ahead energy market, the reserve procurement, and the real-time balancing market in a renewable-dominated power system. Two of the proposed models are inspired by reserve procurement mechanisms currently applied in Europe, where reserves are committed either before (Model 1) or after (Model 2) the clearing of the day-ahead energy market. Then, we use as benchmark a third model in which energy and reserve capacity are co-optimized (Model 3). In all models, we consider the procurement of both conventional and upward/downward reserves. We also assess the impact of these organizations on market participants’ remuneration and test the impact of cross-border constraints as those applying in the European power system. The case study is based on the IEEE 24-node RTS, considering the uncertainty in renewable power production and demand. Our results show that Model 1 is the least efficient market design as it leads to a misallocation of the available capacity, while Model 2 becomes as efficient as Model 3 when the TSOs procure reserve in a coordinated way. Finally, a coordinated procurement of reserves reduces the system operating costs in all models.

An Integrated Assessment of the Environmental and Economic Impact of Offshore Oil Platform Electrification

Electrification of offshore oil and gas installations on the Norwegian continental shelf is one of several options to decrease the CO2 emitted from these installations. However, there is an ongoing debate regarding how the increased electricity consumption will influence the CO2 emissions in the power market, both in the short-run and in the long-run. This paper aims to address the issue and investigate the feasibility of the electrification of a large offshore area in the North Sea in comparison to standard concepts to supply energy offshore. A novel integrated model was developed for the purpose that includes and combines a process model of the offshore power generation units and a model of the European power system. The integration of the two models allows to simultaneously simulate the behavior of the offshore energy conversion systems and the effect of electrification on the onshore power system. The outcomes of the analysis show that the environmental performance of electrification is strongly affected by the selected approach to quantify the CO2 emissions associated with power from shore. Taking standard methods to supply offshore energy as basis for comparison, the marginal effect of electrification would result in increased CO2 emissions (+40%), while the average effect would entail large reductions in CO2 emissions (−48% to −90%), the extent of which depends on the geographical scope selected. An analysis on the economics of electrification indicates that its economic viability would be challenging and would not be favoured by a strong European commitment towards environmental policies since the expected increase of power price will outbalance the gains for the reduced emission costs.

The contribution of North Atlantic atmospheric circulation shifts to future wind speed projections for wind power over Europe

Wind power accounts for a large portion of the European energy mix (17% of total power capacity). European power systems therefore have a significant-and growing-exposure to near-surface wind speed changes. Despite this, future changes in European wind climate remain relatively poorly studied (compared to, e.g., temperature or precipitation), and there is limited understanding of the differences shown by different general and regional circulation models (GCMs and RCMs). This study provides a step towards a process-based understanding of European wind speed changes by isolating the component associated with ‘large-scale’ atmospheric circulation changes in the CMIP5 simulations. The component associated with the large-scale atmospheric circulation is found to explain cold season windiness projections in the free troposphere over Western Europe, with the changes reflecting the poleward shift of the North Atlantic jet. However, in most GCMs the projected wind speed changes near the surface are more negative than would be expected from the large-scale circulation alone. Thus, while the spread in CMIP5 21st century near surface wind speed projections is associated with divergent projections for the large-scale atmospheric circulation, there is a remarkably good agreement concerning a relative reduction in near-surface wind speeds. This analysis suggests that projected 21st century wind speed changes over Western Europe are the result of two distinct processes. The first is associated with changes in the large-scale atmospheric circulation, while the second is likely to be more local in its connection to the near-surface boundary layer. An improved process-based understanding of both is needed for enhancing confidence in wind-power projections on multi-decadal timescales.

Heuristic solution of a joint electric control reserve and wholesale market model

A mixed integer linear programming (MILP) approach for the joint simulation of electric control reserve and electricity wholesale markets is presented. This generation dispatch model extends an existing integrated grid and electricity market (IGEM) model covering the Continental European electric power system. By explicitly incorporating the markets for primary and secondary control reserves (PCR and SCR), the model can reproduce the decisions of generating unit operators on which markets get involved. Besides, the introduction of the integrality conditions allows considering start-up costs and the calculus of generating units to pass through the economically unattractive periods with low or even negative prices in order to avoid another start-up. Since this model is too large to be solved with common MILP solvers for the intended simulation time of one year, temporal and geographical interdependencies are used to solve it heuristically. The heuristic therefore splits the model into various sub-problems so that on the one hand, the number of variables, especially of integer variables, per sub-problem is reduced significantly and on the other hand, the relevant interdependencies remain considered. The heuristic is evaluated in terms of accuracy and computation time by means of two case studies. Both case studies show satisfactory accuracy and significant advantages in computation time.

Analysis of technical and economic parameters of fusion power plants in future power systems

The European power system faces two main challenges: first, the increasing share of fluctuating energy sources in the power generation sector challenges the balance of generation and demand. Second, the expected shift towards using more electricity in the heating and transportation sectors leads to rising demand. To ensure both sufficient energy supply and long-term power system stability of the power system, fusion power is expected to play an important role in the future. This paper provides a sensitivity analysis of fusion power plant parameters in a power system with a large fraction of renewable energies. The results depend strongly on the underlying scenario assumptions, especially on future technical and economic improvements. Finally, the amount of fusion power investments depends on both demand level and relative costs of competing technologies.

Photovoltaics literature survey (no. 149)

Photovoltaics literature survey (no. 149)

The integrated offshore grid in Europe: Exploring challenges for regional energy governance

The deployment of offshore wind and power transmission in the European North Sea is accelerating. Stakeholders advocate regional governance for the European grid expansion, which may evolve into a pan-European governance and is key to developing integrated, hybrid offshore projects. However, such projects are still scarce. We thus analyze the governance of the North Sea offshore grid expansion using the dimensions of level, implementation obligation, and implementation discretion. Our exploratory approach identifies five challenges. The challenges relate to 1) the interaction of the European and regional levels; 2) the interaction of the national and regional levels; 3) the participation of non-European Union countries; 4) the dependence of regional planning on national development plans, which consider national interests; and 5) the interaction of cost allocation and European financing for Projects of Common Interest. The recent Clean Energy Package proposal extensively reforms the regulation of the European power system. The Package is part of the Energy Union strategy and focuses on the energy and climate policies’ governance and the power system operation. Thus, regional governance of offshore expansion is largely unaltered, and our identified challenges remain unaddressed.

Numerical investigation of advanced gas turbine combined cycle coupled with high-temperature nuclear reactor and cogeneration unit

In the European Union by 2050, more than 80% of electricity should be generated using nongreenhousegases energy technology. Nuclear power systems share at present about 15% of the power market and thistechnology can be the backbone of a carbon-free European power system. Energy market transitions are similar to global pathways were analysed in the Intergovernmental Panel on Climate Change report. From a practical point of view currently, the most advanced and most effective technology for electricity generation is based on a gas turbine combined cycle. This technology in a normal way uses natural gas, synthesis gas from the coal gasification or crude oil processing products as the energy carriers but at the same time, such system emits sulphur oxides, nitrogen oxides, and CO2 to the environment. In thepresent paper, a thermodynamic analysis of environmentally friendly power plant with a high–temperature gas nuclear reactor and advanced configuration of gas turbine combined cycle technology is investigated. The presented analysis shows that it is possible to obtain for proposed thermalcycles an efficiency higher than 50% which is not only more than could be offered by traditional coal power plant but much more than can be proposed by any other nuclear technology.

Developing a global interconnected power system model

Decarbonizing the power sector is a necessary step towards a low-carbon future. Interconnecting power systems on different continents could be a method to contribute to such a future, by utilizing highly efficient renewable resources around the globe, while simultaneously providing additional benefits of power system integration. In this paper, we describe the process of constructing and simulating a global interconnected power system model with high technical and temporal resolution. Being the first of its kind on the global scale, this paper is designed to showcase the proof of concept as an intermediate step to a high resolution global model, by integrating an existing European power system model with the North-American continent. The work to date has been focused on testing the methodology and building up necessary knowledge to realistically simulate the functionality of a possible future global grid. Some initial results are analysed to support the viability of the model and the concept in general. Furthermore, key factors influencing the development and optimal performance of the global interconnected power system model are identified.

Residue phase optimization for power oscillations damping control revisited

One of the most used way to tune the parameters of power oscillations damping controllers (like, e.g., the power system stabilizers (PSS) of generators) is to provide a phase compensation to 180 degrees of the phase of the residues of the inter-area modes to be damped and, next, to increase the gains of the controllers in order to obtain the desired damping for the aforementioned modes. It is shown here that this way of doing is suboptimal. First, from the physical point of view, there is no a priori reason to compensate the phase to 180 degrees. Next, concerning the damping of the oscillations, when the phase compensation is computed in a coordinated way with the gain of the controller, better results are systematically obtained. This means that, in comparison with the standard way of phase compensation (to 180 degrees), this new tuning strategy provide the same damping level obtained with lower gains for the controllers (i.e., with more robust controllers) or, alternatively, higher damping levels with the same level of gains (i.e., better performances). The optimal parameters of the controllers are solutions of constrained optimization problems for the general case of several controllers tuned to damp several modes. Examples on both academic and real large-scale (the European power system model) cases are given. This result is general and can be applied to any control framework (for classic generators or more advanced (optimal) control, for local, inter-area or other oscillatory modes).

Balancing future variable wind and solar power production in Central-West Europe with Norwegian hydropower

Norwegian hydropower has an excellent potential to balance power production in a future Central-West European power system with large shares of variable wind and solar resources. The assessment of the realistic potential for Norwegian hydropower to deliver flexibility is based on two pillars, adequate hydropower modelling and the sufficient geographical area covered in the model. Analyses are done with state-of-the-art models including a detailed description of cascaded water-courses with more than thousand reservoirs. Interoperability between hydropower and renewable energy sources is ensured as the entire European electricity generation from renewables with high geographic and temporal resolution is included in the study. To properly account for the full uncertainty of weather variables, many historic years of climate data are applied. The results show that without more flexibility in generation or demand, power prices become very volatile and show expedient periods with capacity deficit and curtailment of demand. Prices vary significantly both from hour-to-hour and from year-to-year. Increases in flexible hydropower provide large benefits to the system: significantly decreasing peak prices and reducing the involuntary shedding of demand. As short-term effects become increasingly important due to large-scale integration of renewable energy sources the correct modelling of flexible hydropower is highly important.

Is a 100% renewable European power system feasible by 2050?

In this study, we model seven scenarios for the European power system in 2050 based on 100% renewable energy sources, assuming different levels of future demand and technology availability, and compare them with a scenario which includes low-carbon non-renewable technologies. We find that a 100% renewable European power system could operate with the same level of system adequacy as today when relying on European resources alone, even in the most challenging weather year observed in the period from 1979 to 2015. However, based on our scenario results, realising such a system by 2050 would require: (i) a 90% increase in generation capacity to at least 1.9 TW (compared with 1 TW installed today), (ii) reliable cross-border transmission capacity at least 140 GW higher than current levels (60 GW), (iii) the well-managed integration of heat pumps and electric vehicles into the power system to reduce demand peaks and biogas requirements, (iv) the implementation of energy efficiency measures to avoid even larger increases in required biomass demand, generation and transmission capacity, (v) wind deployment levels of 7.5 GW y−1 (currently 10.6 GW y−1) to be maintained, while solar photovoltaic deployment to increase to at least 15 GW y−1 (currently 10.5 GW y−1), (vi) large-scale mobilisation of Europe’s biomass resources, with power sector biomass consumption reaching at least 8.5 EJ in the most challenging year (compared with 1.9 EJ today), and (vii) increasing solid biomass and biogas capacity deployment to at least 4 GW y−1 and 6 GW y−1 respectively. We find that even when wind and solar photovoltaic capacity is installed in optimum locations, the total cost of a 100% renewable power system (∼530 €bn y−1) would be approximately 30% higher than a power system which includes other low-carbon technologies such as nuclear, or carbon capture and storage (∼410 €bn y−1). Furthermore, a 100% renewable system may not deliver the level of emission reductions necessary to achieve Europe’s climate goals by 2050, as negative emissions from biomass with carbon capture and storage may still be required to offset an increase in indirect emissions, or to realise more ambitious decarbonisation pathways.

Quantifying the Potential Economic Benefits of Flexible Industrial Demand in the European Power System

The envisaged decarbonization of the European power system introduces complex techno-economic challenges to its operation and development. Demand flexibility can significantly contribute in addressing these challenges and enable a cost-effective transition to the low-carbon future. Although extensive previous work has analyzed the impacts of residential and commercial demand flexibility, the respective potential of the industrial sector has not yet been thoroughly investigated despite its large size. This paper presents a novel, whole-system modeling framework to comprehensively quantify the potential economic benefits of flexible industrial demand (FID) for the European power system. This framework considers generation, transmission, and distribution sectors of the system, and determines the least-cost long-term investment and short-term operation decisions. FID is represented through a generic, process-agnostic model, which, however, accounts for fixed energy requirements and load recovery effects associated with industrial processes. The numerical studies demonstrate multiple significant value streams of FID in Europe, including capital cost savings by avoiding investments in additional generation and transmission capacity and distribution reinforcements, as well as operating cost savings by enabling higher utilization of renewable generation sources and providing balancing services.

An Efficient Network Reduction Method for Transmission Expansion Planning Using Multicut Problem and Kron Reduction

This paper provides a new methodology to compute a reduced but accurate network representation in a transmission expansion planning (TEP) context. Considering this reduced network should lead to the same investment decisions as if the whole original network were considered. A set of relevant lines to be preserved is defined based on a proxy of the TEP solution. An optimal network partition, resulting from solving the multicut problem, is computed in such a way that the two ends of each of these relevant lines are allocated to two different areas. An iterative Kron reduction is then applied to each area to eliminate most of the buses that are not connected to any interarea line. This two-step process results in a compact but representative reduced network. Our algorithm has been implemented in General Algebraic Modelling Software and Matrix Laboratory and has been tested on the standard IEEE 118 bus system and a case study based on the European power system. The method produces very promising results and, in the considered case studies, leads to the same, or equally efficient, investment decisions and essentially the same total costs as when considering the whole original network.

PyPSA-Eur: An open optimisation model of the European transmission system

PyPSA-Eur, the first open model dataset of the European power system at the transmission network level to cover the full ENTSO-E area, is presented. It contains 6001 lines (alternating current lines at and above 220 kV voltage level and all high voltage direct current lines), 3657 substations, a new open database of conventional power plants, time series for electrical demand and variable renewable generator availability, and geographic potentials for the expansion of wind and solar power. The model is suitable both for operational studies and generation and transmission expansion planning studies. The continental scope and highly resolved spatial scale enables a proper description of the long-range smoothing effects for renewable power generation and their varying resource availability. The restriction to freely available and open data encourages the open exchange of model data developments and eases the comparison of model results. A further novelty of the dataset is the publication of the full, automated software pipeline to assemble the load-flow-ready model from the original datasets, which enables easy replacement and improvement of the individual parts. This paper focuses on the description of the network topology, the compilation of a European power plant database and a top-down load time-series regionalisation. It summarises the derivation of renewable wind and solar availability time-series from re-analysis weather datasets and the estimation of renewable capacity potentials restricted by land-use. Finally, validations of the dataset are presented, including a new methodology to compare geo-referenced network datasets to one another.