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• Roithner, Maximilian; Velasco-Herrejón, Paola; Greevenbroek, Koen van; Grochowicz, Aleksander; Vågerö, Oskar & Hvidsten, Tobias Verheugen [Show all 8 contributors for this article] (2025). Balancing act: the cost of wind restrictions in Norway’s electricity transition. Environmental Research: Energy. 2(3). doi: 10.1088/2753-3751/adde62. Full text in Research Archive Show summary

  To meet its commitments under the Paris Agreement and reduce its dependency on energy imports, the pace, and scale of renewable energy deployment across Europe must increase dramatically over the next decade. Such a steep change in the net-zero transition will inevitably necessitate trade-offs with other societal priorities. Here we investigate a case study focused on the opposition towards onshore wind and the compromises that may need to be made to deliver its plans for deep electrification. Using an electricity system model, we explore the implications of key social and environmental dimensions shaping the future deployment of onshore wind on the costs and design of electricity systems for Norway in 2030. We find that under restrictions that allow for almost no additional onshore wind, demand cannot be met and load has to be shed. Yet, when reducing the restrictions on onshore wind or allowing for in-country transmission expansion, feasible system designs at a small fraction of that cost can be found. To meet the net-zero targets, compromises will need to be made on either wind power deployment, transmission expansion, non-electrification of industry or demand reduction.

• Lombardi, Francesco; Greevenbroek, Koen van; Grochowicz, Aleksander; Lau, Michael; Neumann, Fabian & Patankar, Neha [Show all 7 contributors for this article] (2025). Near-optimal energy planning strategies with modeling to generate alternatives to flexibly explore practically desirable options. Joule. p. 102144–102144. doi: 10.1016/j.joule.2025.102144. Full text in Research Archive Show summary

  Cost-optimizing energy planning models are widespread in supporting energy transition planning decisions. Nonetheless, finding a ‘‘cost-optimal’’ planning strategy provides only a false sense of certainty. Stakeholders may prefer other economically comparable alternatives due to unaccounted-for features. Multi-objective or robust optimization, among others, can efficiently explore alternatives whose desired secondary features are well defined. ‘‘Modeling to generate alternatives’’ (MGA) explores alternatives systematically, including alternatives whose features, such as social viability, are hard to model, albeit key to practical implementation. Computational and interpretation barriers hindered past MGA usage and integration with other methods, but recent developments enable going beyond such barriers. We synthesize such developments and provide practical recommendations for applying MGA in five levels of increasing benefit. Even the simplest levels, requiring little computational effort, can substantially improve the quality of energy planning analyses. At the highest level of integration, MGA can facilitate identifying consensus strategies, accelerating the energy transition.

• Greevenbroek, Koen van; Grochowicz, Aleksander; Zeyringer, Marianne & Benth, Fred Espen (2025). Trading off regional and overall energy system design flexibility in the net-zero transition. Nature Sustainability. doi: 10.1038/s41893-025-01556-2. Full text in Research Archive Show summary

  Thetransitiontonet-zeroemissionsinEuropeisdeterminedbyapatchworkofcountry-levelandEUwide policy, creating coordination challenges in an interconnected system. We use an optimisation model to mapoutnear-optimal energy system designs for 2050, focussing on the planning flexibility of individual regions while maintaining overall system robustness against different weather years, cost assumptions, and land use limitations. Our results reveal extensive flexibility at a regional level, where only few technologies (solar around the Adriatic and wind on the British Isles and in Germany) cannot be substituted. National policymakers can influence renewable energy export and hydrogen strategies significantly, provided they coordinate this with the remaining European system. However, stronger commitment to solar in Southern Europe and Germany unlocks more design options for Europe overall. These results on regional trade-offs facilitate more meaningful policy discussions which are crucial in the transition to a sustainable energy system.

• Grochowicz, Aleksander; Benth, Fred Espen & Zeyringer, Marianne (2024). Spatio-temporal smoothing and dynamics of different electricity flexibility options for highly renewable energy systems—Case study for Norway. Applied Energy. ISSN 0306-2619. 356. doi: 10.1016/j.apenergy.2023.122338. Full text in Research Archive Show summary

  In this article, we investigate the mismatch of renewable electricity production to demand and how flexibility options enabling spatial and temporal smoothing can reduce risks of variability. As a case study we pick a simplified (partial) 2-region representation of the Norwegian electricity system and focus on wind power. We represent regional electricity production and demand through two stochastic processes: the wind capacity factors are modelled as a two-dimensional Ornstein–Uhlenbeck process and electricity demand consists of realistic base load and temperature-induced load coming from a deseasonalised autoregressive process. We validate these processes, that we have trained on historical data, through Monte Carlo simulations allowing us to generate many statistically representative weather years. For the investigated realisations (weather years) we study deviations of production from demand under different wind capacities, and introduce different scenarios where flexibility options like storage and transmission are available. Our analysis shows that simulated loss values are reduced significantly by cooperation between regions and either mode of flexibility. Combining storage and transmission leads to even more synergies and helps to stabilise production levels and thus reduces likelihoods of inadequacy of renewable power systems.

• Grochowicz, Aleksander; Greevenbroek, Koen van & Bloomfield, Hannah C. (2024). Using power system modelling outputs to identify weather-induced extreme events in highly renewable systems. Environmental Research Letters. 19(5). doi: 10.1088/1748-9326/ad374a. Full text in Research Archive Show summary

  In highly renewable power systems the increased weather dependence can result in new resilience challenges, such as renewable energy droughts, or a lack of sufficient renewable generation at times of high demand. The weather conditions responsible for these challenges have been well-studied in the literature. However, in reality multi-day resilience challenges are triggered by complex interactions between high demand, low renewable availability, electricity transmission constraints and storage dynamics. We show these challenges cannot be rigorously understood from an exclusively power systems, or meteorological, perspective. We propose a new method that uses electricity shadow prices—obtained by a European power system model based on 40 years of reanalysis data—to identify the most difficult periods driving system investments. Such difficult periods are driven by large-scale weather conditions such as low wind and cold temperature periods of various lengths associated with stationary high pressure over Europe. However, purely meteorological approaches fail to identify which events lead to the largest system stress over the multi-decadal study period due to the influence of subtle transmission bottlenecks and storage issues across multiple regions. These extreme events also do not relate strongly to traditional weather patterns (such as Euro-Atlantic weather regimes or the North Atlantic Oscillation index). We therefore compile a new set of weather patterns to define energy system stress events which include the impacts of electricity storage and large-scale interconnection. Without interdisciplinary studies combining state-of-the-art energy meteorology and modelling, further strive for adequate renewable power systems will be hampered.

• Grochowicz, Aleksander; Greevenbroek, Koen van; Benth, Fred Espen & Zeyringer, Marianne (2023). Intersecting near-optimal spaces: European power systems with more resilience to weather variability. Energy Economics. ISSN 0140-9883. 118. doi: 10.1016/j.eneco.2022.106496. Full text in Research Archive Show summary

  We suggest a new methodology for designing robust energy systems. For this, we investigate so-called near-optimal solutions to energy system optimisation models; solutions whose objective values deviate only marginally from the optimum. Using a refined method for obtaining explicit geometric descriptions of these near-optimal feasible spaces, we find designs that are as robust as possible to perturbations. This contributes to the ongoing debate on how to define and work with robustness in energy systems modelling. We apply our methods in an investigation using multiple decades of weather data. For the first time, we run a capacity expansion model of the European power system (one node per country) with a three-hourly temporal resolution and 41 years of weather data. While an optimisation with 41 weather years is at the limits of computational feasibility, we use the near-optimal feasible spaces of single years to gain an understanding of the design space over the full time period. Specifically, we intersect all near-optimal feasible spaces for the individual years in order to get designs that are likely to be feasible over the entire time period. We find significant potential for investment flexibility, and verify the feasibility of these designs by simulating the resulting dispatch problem with four decades of weather data. They are characterised by a shift towards more onshore wind and solar power, while emitting more than 50% less CO2 than a cost-optimal solution over that period. Our work builds on recent developments in the field, including techniques such as Modelling to Generate Alternatives (MGA) and Modelling All Alternatives (MAA), and provides new insights into the geometry of near-optimal feasible spaces and the importance of multi-decade weather variability for energy systems design. We also provide an effective way of working with a multi-decade time frame in a highly parallelised manner. Our implementation is open-sourced, adaptable and is based on PyPSA-Eur.

• Craig, Michael T.; Wohland, Jan; Stoop, Laurens P.; Kies, Alexander; Pickering, Bryn & Bloomfield, Hannah C. [Show all 23 contributors for this article] (2022). Overcoming the disconnect between energy system and climate modeling. Joule. 6(7), p. 1405–1417. doi: 10.1016/j.joule.2022.05.010. Full text in Research Archive Show summary

  Energy system models underpin decisions by energy system planners and operators. Energy system modeling faces a transformation: accounting for changing meteorological conditions imposed by climate change. To enable that transformation, a community of practice in energy-climate modeling has started to form that aims to better integrate energy system models with weather and climate models. Here, we evaluate the disconnects between the energy system and climate modeling communities, then lay out a research agenda to bridge those disconnects. In the near-term, we propose interdisciplinary activities for expediting uptake of future climate data in energy system modeling. In the long-term, we propose a transdisciplinary approach to enable development of (1) energy-system-tailored climate datasets for historical and future meteorological conditions and (2) energy system models that can effectively leverage those datasets. This agenda increases the odds of meeting ambitious climate mitigation goals by systematically capturing and mitigating climate risk in energy sector decision-making.

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• Melteig, Elina & Grochowicz, Aleksander (2023). Strømmarkedet: Hva skjer hvis vi kobler Nord- og Sør-Norge? [Internet]. forskning.no, tu.no, titan.uio.no. Full text in Research Archive
• Grochowicz, Aleksander & Zeyringer, Marianne (2023). Managing the variability in time and geography of renewable power generation. Full text in Research Archive
• Grochowicz, Aleksander (2023). The role of historical weather data and how that can be used for a more resilient energy transition. Full text in Research Archive
• Grochowicz, Aleksander & Zeyringer, Marianne (2023). Managing the variability in time and space of renewable power generation. Full text in Research Archive
• Grochowicz, Aleksander; Greevenbroek, Koen van; Benth, Fred Espen & Zeyringer, Marianne (2023). Intersecting Near-Optimal Spaces for Policy Information. Full text in Research Archive
• Grochowicz, Aleksander (2023). Spatio-temporal smoothing and dynamics of different electricity flexibility options. Full text in Research Archive
• Greevenbroek, Koen van; Zeyringer, Marianne; Noll, Josef; Grochowicz, Aleksander & Vågerö, Oskar (2023). Kjernekraft er ikkje naudsynt for Noreg. Det vil heller ikkje lønna seg. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. Full text in Research Archive
• Grochowicz, Aleksander; Greevenbroek, Koen van & Bloomfield, Hannah C. (2023). Identifying weather stress events from power system optimisation outputs. Full text in Research Archive
• Grochowicz, Aleksander (2023). Identifying weather stress events from power system optimisation outputs. Full text in Research Archive
• Greevenbroek, Koen van; Grochowicz, Aleksander & Bloomfield, Hannah C. (2023). Identifying Weather Stress Events from Power System Optimisation Outputs. Full text in Research Archive
• Greevenbroek, Koen van; Grochowicz, Aleksander; Zeyringer, Marianne; Noll, Josef & Vågerö, Oskar (2023). Vi treng uavhengig forsking, ikkje drøymetenking om kjernekraft. Aftenposten (morgenutg. : trykt utg.). ISSN 0804-3116. Full text in Research Archive
• Grochowicz, Aleksander (2022). Intersecting near-optimal spaces for more resilience against weather variability. Full text in Research Archive
• Greevenbroek, Koen van & Grochowicz, Aleksander (2022). Effect of different weather years on policymakers’ decision space. Full text in Research Archive
• Grochowicz, Aleksander; Greevenbroek, Koen van; Benth, Fred Espen & Zeyringer, Marianne (2022). Intersecting near-optimal spaces for robust energy systems. Full text in Research Archive
• Zeyringer, Marianne; Benth, Fred Espen; Roithner, Maximilian; Grochowicz, Aleksander & Sirotko-Sibirskaya, Natalia (2022). Climate-resilient net-zero energy system design. Full text in Research Archive
• Grochowicz, Aleksander (2024). Resilience and weather uncertainty in energy system models. Universitetet i Oslo. Full text in Research Archive
• Grochowicz, Aleksander; Heineken, Daniel & Wennberg, Sondre (2021). The reliability of wind power in the Longyearbyen area. Universitetssenteret på Svalbard. Full text in Research Archive Show summary

  This report in a white paper format was written as part of the course AGF-353/853 "Sustainable Arctic Energy Exploration and Development" at the University Centre in Svalbard (UNIS). --- Within this decade the current energy system in Longyearbyen has to be revolutionised. Right now, it relies entirely on fossil fuels, but in the future it is envisioned to be a front-runner of renewable systems in the Arctic. Due to the polar night and restricted renewable resources, the reliability of wind power is of crucial importance in this transition. Additionally, the permafrost and remote location demand high robustness and simple maintenance. In this report, we analyse on-shore wind potential in three different locations over the previous decade, including an evaluation of stability and extreme events in Svalbard's harsh climate. To ensure long-term success of this transition, we look at interannual, seasonal, and sub-monthly variations that should be included in suitability assessments. Based on our analysis, disregarding this could lead to installations that can jeopardise the stability of the system. With generated input data that we feed into an energy systems model, we find that if one considers interannual variability and a set of different locations, one can ensure a viable and reliable renewable energy system for Longyearbyen, with on-shore wind as a key component.

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