Electricity supply in European countries faces a number of challenges, such as achieving carbon neutrality, tackling rising prices, reducing dependence on fossil fuels, including fossil fuel imports. To achieve these goals, the electricity systems of all European countries will have to undergo major changes, while taking into account technical, environmental, economic and social objectives. Our simulations provide essential data for this transition by analyzing different power plant portfolios and electricity consumption scenarios. The analyses focus on the cooperation of nuclear power and weather-dependent renewables, and on the possible role that battery-based electricity storage can play in the Hungarian electricity system.In this paper, we present the experience gained in setting up an electricity market model and the results of running the model on the electricity systems of Hungary and its six neighboring countries (Slovakia, Romania, Serbia, Croatia, Slovenia and Austria), taking into account the constraints of the cross-border capacities. The results of the sensitivity analysis for the 2030 power plant portfolios, battery capacities and renewables analyzed in this paper cover Hungary's import/export position, the energy source structure of its electricity generation, battery operation, CO2 emissions from electricity generation, expected prices in the system and the utilization parameters of nuclear power plants.

Best-estimate thermal-hydraulic system codes are widely used for the analysis of various postulated events of NPPs, therefore, an extensive verification and validation of these codes is essential. In the current study, an SBLOCA scenario (CL-4.1-03) of the PSB-VVER integral test facility has been investigated using NRC's novel system code, TRACE, and the Finnish APROS, which had already been in long use at our Institution. PSB-VVER is currently the most comprehensive physical model of the VVER-type reactors, particularly VVER-1000, in most of the aspects. The experiment under study was carried out in 2004 in the framework of an OECD NEA benchmark. The obtained results have been compared to the benchmark and to each other both from a qualitative and quantitative point of view. As a figure of merit, the improved FFTBM-SM and the SARBM quantitative methods were used. Furthermore, the main lessons learnt during the model development are also presented.

Mars exploration has a history of more than half a century and has been the subject of numerous expeditions over the past nearly 70 years. Much of this exploration has been motivated by the idea of colonizing the planet. Providing energy to a Martian colony is a challenging task due to the challenging conditions and the need for special equipment. There are a number of options for supplying energy to a colony, with nuclear, solar, geothermal and wind all being explored. Solar and nuclear energy have the greatest potential, and our research is looking at how these energy sources could power the colony.In our research, we calculated the energy use of a potential Martian colony and combined these to assess the potential for generating the demand we estimated. We have calculated the oxygen demand and its production, and we have investigated the theoretical possibility of a new process for waste management to produce recycled acrylonitrile butadiene styrene for 3D printing. We have also calculated the gamma irradiation dose of Martian samples and the energy requirements of the equipment needed to produce it, the extraction of water and its application in agriculture. We also evaluated the potential of nuclear reactors and solar energy. Our calculations provide a good basis for a full simulation of the energy system of a Martian colony.

Nuclear power plants play an extremely important role in the European Union's electricity supply. Nuclear power is the largest carbon neutral source of electricity and the most important baseload electricity producer in Europe. The existing 167 units represent a capacity of 148 000 MW, which in 2022 accounted for 22 % of the electricity generated in the EU-27. In most countries, there are plans to keep nuclear power plants in operation and then extend their lifetime. In most of the European countries that already have nuclear power the construction of new units is planned, as well as in Poland, which is a nuclear newcomer. Meanwhile, Germany has phased out nuclear power in 2023 and this move is also being considered in other countries. In this article, we address the question of what the impact would be in the EU member states if nuclear power plants were to be phased out and replaced by solar, wind and gas-fired capacities. To do this, energy strategies for EU countries with nuclear power were analysed, hourly resolution electricity supply models were constructed for 15 countries and the main electricity supply characteristics for year 2030 and 2040 were assessed for three different power plant portfolios in each country under study. For the different scenarios, specific results are presented on the primary energy mix, CO2 emissions, natural gas demand and high time resolution characteristics of electricity supply.

The increasing penetration of weather-dependent renewable energy generation calls for high-resolution modeling of the possible future energy mixes to support the energy strategy and policy decisions. Simulations relying on the data of only a few years, however, are not only unreliable but also unable to quantify the uncertainty resulting from the year-to-year variability of the weather conditions. This paper presents a new method based on artificial neural networks that map the relationship between the weather data from atmospheric reanalysis and the photovoltaic and wind power generation and the electric load. The regression models are trained based on the data of the last 3 to 6 years, and then they are used to generate synthetic hourly renewable power production and load profiles for 42 years as an ensemble representation of possible outcomes in the future. The modeled profiles are post-processed by a novel variance-correction method that ensures the statistical similarity of the modeled and real data and thus the reliability of the simulation based on these profiles. The probabilistic modeling enabled by the proposed approach is demonstrated in two practical applications for the Hungarian electricity system. First, the so-called Dunkelflaute (dark doldrum) events, are analyzed and categorized. The results reveal that Dunkelflaute events most frequently happen on summer nights, and their typical duration is less than 12 h, even though events ranging through multiple days are also possible. Second, the renewable energy supply is modeled for different photovoltaic and wind turbine installed capacities. Based on our calculations, the share of the annual power consumption that weather-dependent renewable generation can directly cover is up to 60% in Hungary, even with very high installed capacities and overproduction, and higher carbon-free electricity share targets can only be achieved with an energy mix containing nuclear power and renewable sources. The proposed method can easily be extended to other countries and used in more detailed electricity market simulations in the future.

Összefoglaló. Írásunk a magyar villamosenergia-rendszert vizsgálja a COVID–19 koronavírus-járvány időszakában. Bemutatjuk a járvány magyarországi alakulásának villamosenergia-fogyasztásra gyakorolt hatását. Elemezzük a magyar villamosenergia-fogyasztási adatokat a 2019. és a 2020. év vonatkozásában, összehasonlítjuk a fogyasztás és a GDP negyedéves változását 2020-ban, és összevetjük a magyar villamosenergia-rendszerben bekövetkezett változásokat egyes európai országok rendszerének adataival. Cikkünk végén röviden bemutatjuk a villamosenergia-rendszer mint kritikus infrastruktúra működtetésének mindennapjait a járvány alatt, amely rendszer ebben a mindenki számára megerőltető időszakban is folyamatosan biztosította a fogyasztók biztonságos és megbízható villamosenergia-ellátását. Summary. The pandemic situation caused by the coronavirus has momentarily changed the lives of everyone in the world. With the closure of borders and the imposition of curfews, tourism practically stopped overnight, civil aviation shut down, offices and some manufacturing plants closed, people were forced to stay in their homes for months, worldwide. It must also be taken into account that intensive air travel and a globalised world economy clearly predispose the world to a greater frequency of pandemics in the future, and that society, the country and humanity as a whole must be prepared to deal more effectively with similar epidemics. This salutatory change is certainly worth analysing, as much can be learned from the current situation. In this article, we analyse the energy aspects of the epidemic, as the virus has left a deep imprint even in this industry. For the analysis, it is essential to describe the behavior of the COVID-19 pandemic in Hungary and the measures taken in parallel to contain the outbreak, as these measures have had a significant impact on the country’s electricity system. We examined the electricity consumption trends for 2020 compared to 2019. We show how the consumer sides of different European electricity systems have reacted to the situation. We conclude by highlighting the changes in the critical energy infrastructure that, despite the difficulties caused by the epidemic, the Hungarian electricity system has provided the population with the electricity which is increasingly essential to our daily lives. The current situation highlights even more that the main infrastructures of modern societies, such as industrial production plants, transport, commerce, health care, information technology and even households, cannot function without a reliable and secure electricity supply. It is therefore of paramount importance to ensure the operational conditions of the electricity system as critical infrastructure, even during a pandemic.

The European Green Deal is setting clear objectives for the transformation of the economy into a cleaner and at the same time competitive working model. The energy sector and especially the electricity sector faces serious challenges in order to comply with the objectives set by the policy. Aging power plants and grid infrastructure, phasing out fossil based energy production, the nuclear phase-out in some countries, increasing weather dependent intermittent power sources, the requirements of the security of electricity supply are also individually stressing issues, but all together are even more challenging.In line with the Treaty on the Functioning of the European Union (TFEU) the energy strategy is the competence of the individual countries, based on the fact that the different countries have very different geological, socio-economical and ecological conditions, and their access to natural resources can be diverse. Therefore the national governments and national Parliaments are setting the national strategies which has to be in-line with the European framework. An important question arises evidently, namely, whether the national pieces of the big European Puzzle will result to a picture that has been set by the European Green Deal published on 14th July 2021?In the research presented in this paper, we tried to answer the abovementioned questions by investigating the energy strategy of 19 countries situated in continental Europe. We ran simulations for the year 2030 and 2040 using full year models with hourly resolution to investigate if the power plant portfolios of the individual countries could cover the electricity needs foreseen by their national energy strategies. Possible curtailment and unserved demand of the 19 countries in question were summed and final conclusions were drawn based on the simulation results.