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Lightning protection of large‐scale photovoltaic power stations and grid‐connected lines has gradually become a difficult problem with more and more large‐scale photovoltaic power stations connected to the State Grid. In order to enable large photovoltaic power station to continue and stably operate, this paper targeted the grid‐connected transmission line and designed the spiral multi‐pair blowing device. The device leads the plasma arc to take on a spiral path, and the energy of plasma arc is sprayed out at the convection fracture of the unit and continuously consumed. Experiment results show that the device can extinguish lightning current in 2.1 ms and restore the transmission voltage to the normal level. The lightning protection device has the effectiveness of arc extinguishing, and it is beneficial to reduce lightning trip rate of transmission line of large‐scale photovoltaic power stations. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

With the integration of large-scale photovoltaic power stations into power grids, the traditional strategy of the backup automatic switch is affected. When a grid fault occurs, due to the existence of photovoltaic power sources, the busbar voltage at the fault point cannot meet the 'no voltage' criterion, and the traditional strategy cannot operate correctly. In order to improve new energy utilization and ensure normal input of the backup power supply without disconnecting photovoltaic power sources, a new backup automatic switch scheme based on distributed buffer resistors is proposed. Firstly, the influence of the mismatch between photovoltaic output and load power on the grid-connected point voltage is analyzed. Secondly, distributed buffer resistor branches are connected in parallel at both ends of the DC capacitor in each photovoltaic power generation unit, using buffer resistors to suppress the power imbalance formed in the islanded state after the main power supply is disconnected (before the backup automatic switch operates), realizing safe and fast operation of the backup automatic switch. Finally, MATLAB/Simulink is used to simulate and verify the scenario of extreme mismatch between photovoltaic and load power, and the inrush current can be limited to 1.5 times rated current, which meets the relevant specifications and verifies the feasibility and effectiveness of the proposed new backup automatic switch scheme.

The photovoltaic industry is developing rapidly because of its renewable energy and other advantages. However, the installation of this infrastructure may affect soil, vegetation, and carbon dynamics, making it is necessary to carry out vegetation restoration work at a plant's location in the later stages of its construction. For this reason, three types of artificial vegetation were selected (Pinus sylvestris var. mongolica, Astragalus membra-naceus var. mongholicus and Medicago sativa) as research objects in an ecological photovoltaic power plant in Northern China, to study the changes in soil organic carbon storage (SOCS), carbon:nitrogen ratios (C:N) and C:phosphorus ratios (C:P) at different soil depths and for different vegetation types. Natural vegetation plots undisturbed by the construction of the power plant were used as a control. Seven years after revegetation, we found that the storage and content of soil organic carbon in all three artificial vegetation plots were notably lower compared to the control. Nevertheless, the soil's organic carbon content for Medicago sativa plots increased was significantly higher by 1.2 g·kg−1 compared to Pinus sylvestris var. mongolica and A. membranaceus var. mongholicus plots, while organic carbon storage increased significantly by 3.55 t·ha and 7.15 t·ha. SOCS, C:N, and C:P concentrations in the 0–20 cm soil layer exhibited a significantly higher value in comparison to those of the 20–40 cm soil layer. As the soil depth increased, all the concentrations declined gradually. Vegetation type and soil depth, as well as their interaction, had a significant impact on soil carbon storage, C:N, and C:P. The study area was restricted by the availability of P. In general, vegetation restoration is a beneficial ecological practice for soil restoration at photovoltaic power stations. It is believed that planting alfalfa can accelerate the improvement of soil carbon with an extension of vegetation recovery time. In order to restore the balance of nutrients for plants, it is necessary to avoid human interference at the later stage, and to supplement phosphorus as soon as possible to minimize phosphorus limitation at the later stage of vegetation growth, which is of great importance to increasing the likelihood of success in reclaiming disturbed land. [ABSTRACT FROM AUTHOR]

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To achieve carbon peaking and carbon neutrality in China, photovoltaic (PV) power generation has become increasingly important for promoting a low-carbon transition. The central and western desert areas of China have been identified as major areas for the construction of large PV bases. Remote sensing technology has been used to map the spatial distribution and development status of PV power stations quickly and accurately in ecologically fragile areas, as well as assess the ecological and environmental impact of their construction. However, current remote sensing monitoring of PV power stations focuses mainly on mapping and time series analysis to measure their development process and assess the environmental conditions on a large scale over a long period of time. Therefore, we constructed a random forest model based on image spectral and texture features and mapped 2022 PV power stations in the junction area of Hobq Desert, Ulan Buh Desert, Tengger Desert, and Mu Us Sands in China. Following that, we identified the construction time of the PV power stations by identifying the turning points of the normalized construction land index (NDBI) time series from 1990–2022 using the LandTrendr method. To assess the ecological impact of PV power stations, we used the NDVI to measure the change in vegetation condition before and after the construction of PV power stations and constructed NDVI changes for PV power stations constructed in different years. The results showed that this mapping method achieved an overall classification accuracy of 96.65% and a Kappa coefficient of 0.92. The root mean square error (RMSE) for construction year identification was less than 0.5, and the number of new PV power stations increased significantly after 2010, reaching a total area of 14.52 km2 by 2016, which is consistent with the trend driven by national and regional development plans. Furthermore, the study found that the vegetation cover level could be restored to the average level before construction within 5–6 years and continued to increase after that. These findings may help government policymakers and practitioners make decisions on PV power station planning and ecological environment protection, thus contributing promptly to the achievement of China's dual carbon goals. [ABSTRACT FROM AUTHOR]

Europe is currently facing the potentially biggest energy crisis in history. There are many reasons for this, and the current geopolitical situation makes it clear that we are being forced to take immediate action to ensure sufficient energy supplies to consumers. Until recently, the European Union was dependent on Russian energy resources (mainly oil and gas). For many years, the EU countries had been shutting down their own production and importing much cheaper raw material from Russia. The threat of a blackout is becoming increasingly possible. European governments are preparing businesses and households for the energy crisis in various ways, but there is also a great deal of mobilization to accelerate the development of renewable energy sources (RES). The aim of this study was to identify the barriers and prospects for RES development in Poland in the current geopolitical conditions. The reasons for insufficient grid HC were analyzed. Additionally, the article aimed to assess the prospects for solar energy development in Poland. Wind power was discussed only in general terms because the development of wind farms is inhibited by the regulatory framework. Particular attention was paid to hosting capacity (HC) and the condition of the power infrastructure as the main determinants of RES development in Poland. Numerous documents developed by power companies and government agencies responsible for implementing and managing energy in Poland were analyzed. Special attention was paid to legal regulations and the need for legislative changes. As a country, Poland has one of the highest growth rates in photovoltaic (PV) installations. The forecasts for increasing HC, as a prerequisite for RES development in Poland, are not promising. [ABSTRACT FROM AUTHOR]

The objective of Poland's energy policy is to guarantee energy security while enhancing economic competitiveness and energy efficiency, thus minimizing the power sector's environmental impact and optimizing the use of energy resources in the country. Poland is not the only European country to rely on coal for power generation. Historical factors and large coal deposits act as natural barriers to increasing the share of renewable energy in the Polish power sector. Yet, today, environmental concerns and climate change are prompting many countries to move away from fossil fuels. Renewable energy sources, such as solar and wind energy, are an alternative to traditional energy generated from fossil fuels. However, investors developing solar and wind farms in Poland encounter numerous problems at each stage of the project. These difficulties are associated mainly with the location, technical requirements, infrastructure and formal and legal documents. This study aimed to identify the key factors that influence the development of photovoltaic power stations in Poland, with special emphasis on the choice of location and technical aspects of the investment process. The demand for clean energy and the renewable energy prospects for Poland are discussed based on the example of solar farms. Sixty-seven prospective farm locations were analyzed, and the results of the analysis were used to identify the main barriers and opportunities for renewable energy development in Poland. The option of connecting solar farms to the existing power grid was also examined. This study demonstrates that the development of solar farms in Poland is inhibited mainly by technical barriers, in particular the lack of options for connecting farms to the power grid, as well as the absence of support mechanisms and dedicated legislative solutions, rather than environmental obstacles. [ABSTRACT FROM AUTHOR]

Photovoltaic power is a rapidly growing component of the renewable energy sector. Photovoltaic power stations (PVPSs) on coastal tidal flats offer benefits, but the lack of information on the effects of PVPSs on benthic ecosystems and sediment carbon storage can hamper the development of eco-friendly renewable energy. We sampled the macrobenthos and sediment cores at a PVPS on a coastal tidal flat in eastern China. The biodiversity indicators and benthic ecological quality based on macrobenthos were mostly higher under the photovoltaic panels than elsewhere. These variations were primarily driven by pH, sediment grain size, and chlorophyll- a content. However, the PVPS had exerted a considerable influence on the macrobenthic community structure. Furthermore, the carbon stocks in the sediment cores from under the photovoltaic panels were similar to those in the reference sites. These results suggest that this PVPS has not had discernible short-term adverse effects on the benthic ecosystems or sediment carbon storage of the tidal flat. Nevertheless, the potentially long-term and cascading risks throughout the ecosystem warrant caution. Therefore, we recommend that policymakers adopt a cautious development strategy and implement long-term, high-frequency monitoring to ensure the sustainability of renewable energy production on coastal tidal flats.

In order to solve the problem of long-distance transmission of large-scale photovoltaic power stations, a multi-terminal voltage source converter-based high-voltage direct current (VSC–HVDC) system based on a DC voltage-active power-AC voltage control strategy, which is connected with photovoltaic power stations, is designed in this study. In order to verify the feasibility of the method, a model of a five-terminal parallel system is established by MATLAB/Simulink, which includes two photovoltaic power stations and a passive network. A series of simulations are carried out based on the model. The results show that the active power of the system can be automatically balanced when the output power of photovoltaic power stations changes. When the three-phase short-circuit fault occurs in power grid, the photovoltaic power stations can still run in a stable state and have better fault ride-through ability.

In order to solve the problem of long-distance transmission of large-scale photovoltaic power stations, a multi-terminal voltage source converter-based high-voltage direct current (VSC–HVDC) system based on a DC voltage-active power-AC voltage control strategy, which is connected with photovoltaic power stations, is designed in this study. In order to verify the feasibility of the method, a model of a five-terminal parallel system is established by MATLAB/Simulink, which includes two photovoltaic power stations and a passive network. A series of simulations are carried out based on the model. The results show that the active power of the system can be automatically balanced when the output power of photovoltaic power stations changes. When the three-phase short-circuit fault occurs in power grid, the photovoltaic power stations can still run in a stable state and have better fault ride-through ability. [ABSTRACT FROM AUTHOR]

The policy of transaction mode of direct electricity purchase by large consumers will further reduce the power system scheduling space. When large-scale non-controllable wind turbines and photovoltaic power stations are connected to the system, the optimal scheduling of the system will face even more severe challenges. In order to analyse the impact of the direct purchase of large consumers on the system capacity of renewable energy, this paper proposes a scheduling model of power system with renewable energy and transaction mode of direct electricity purchase by large consumers considering network security constraints. By taking into account the network security constraints, this model can compute large power system and analyse the impact of the direct electricity purchase unit access node on renewable consumption capacity of the system. To illustrate the effectiveness of the proposed model, a real power system in a northern province of China is used in the case study. The consumed renewable energy is calculated and the reason for the wind and solar power curtailment is analysed. The influence of real-time price, contract size, and the unit access node of the direct electricity purchase on renewable energy consumption capacity of the system is analysed. [ABSTRACT FROM AUTHOR]

The policy of transaction mode of direct electricity purchase by large consumers will further reduce the power system scheduling space. When large-scale non-controllable wind turbines and photovoltaic power stations are connected to the system, the optimal scheduling of the system will face even more severe challenges. In order to analyse the impact of the direct purchase of large consumers on the system capacity of renewable energy, this paper proposes a scheduling model of power system with renewable energy and transaction mode of direct electricity purchase by large consumers considering network security constraints. By taking into account the network security constraints, this model can compute large power system and analyse the impact of the direct electricity purchase unit access node on renewable consumption capacity of the system. To illustrate the effectiveness of the proposed model, a real power system in a northern province of China is used in the case study. The consumed renewable energy is calculated and the reason for the wind and solar power curtailment is analysed. The influence of real-time price, contract size, and the unit access node of the direct electricity purchase on renewable energy consumption capacity of the system is analysed.

As the number and capacity of photovoltaic (PV) power stations increase, it is of great significance to evaluate the PV-connected power systems in an effective, reasonable, and quick way. In order to overcome the challenge of PV’s time-sequential characteristic and improve upon the computational efficiency, this paper presents a new methodology to evaluate the reliability of the power system with photovoltaic power stations, which combines intelligent state space reduction and a pseudo-sequential Monte Carlo simulation (PMCS). First, a non-aggregate Markov model of photovoltaic output is established, which effectively retains some time-sequential representation of the PV output. Then, the differential evolution algorithm (DE) is introduced into the sampling stage of PMCS to carry out an intelligent state space reduction (ISSR). By using the DE algorithm, success states are searched out and removed, thus the state space is reduced and formed with a high density of loss-of-load. Hence, unnecessary samplings are avoided, which optimizes the PMCS sampling mechanism and improves the computational efficiency. Finally, the proposed method is tested in the modified IEEE RTS-79 system. The results indicate that this new method has a better computational efficiency than the time-sequential Monte Carlo simulation method (TMCS) and pure PMCS. In addition, the effectiveness and feasibility of this method are also verified.

Copyright of Financial Sciences / Nauki o Finansach is the property of Uniwersytet Ekonomiczny we Wroclawiu and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)