The cultivation of energy biomass in Slovakia is regulated by multiple legal acts, requiring an interdisciplinary approach. Navigating the relevant legal norms can be challenging for biomass growers. The Renewable Energy Directive supports the European Green Deal goals, particularly climate change mitigation and emission reduction, by promoting renewable energy, including sustainably grown biomass on agricultural and forest land. The main objective of this article is to evaluate the transposition of the Directive into Slovak law, especially in relation to the sustainability criteria for biomass cultivation. The cultivation of biomass alone does not guarantee the achievement of the Green Deal's objectives. These can only be fulfilled through properly defined, verified, and respected sustainability criteria. However, EU-level criteria are unlikely to fully reflect the national specificities of all 27 Member States. Therefore, while the EU legislation emphasizes environmental aspects, it also allows Member States to introduce additional sustainability criteria-at least for biomass fuels. Despite this flexibility, the Slovak legislator has transposed the Directive almost verbatim, without creating a systematic legal framework for biomass growers and processors. The current legislation requires a unified terminology, harmonized procedures for establishing stands on agricultural and forest land, as well as certainty regarding subsidy mechanisms throughout the entire cultivation period. This article is intended not only to help potential biomass growers navigate the complex legal framework but also to provide some proposals for local and national policymakers.
Hybrid renewable energy systems are one of the highly suitable solutions for the growing energy demand. However, the performance of this system is significantly affected by the power imbalance, unstable DC-bus voltage, and reduced system efficiency. To overcome these issues, a novel HawkDeep Gradient Fuzzy Recurrent Control framework is proposed. This method is used to optimize the management of power characteristics and stabilize the system performance in High Renewable Energy Systems. Moroever the current control algorithms frequently rely on predefined rules, which are not flexible enough to deal with sudden and erratic variations in load demands and power generation. To resolve this, an Intelligent Hawk Fuzzy Control Algorithm is proposed, which integrates fuzzy logic with Reflective Quasi-Hawk Optimization to rapidly get the best answers, thereby guaranteeing the balanced power supply and demand even in the event of sudden inrush currents. Furthermore, the mismatch in ramp rates causes temporary power imbalances and instability in the direct current bus voltage, stressing the system and reducing efficiency. Therefore, a Deep Recurrent Policy Gradient technique is introduced, which integrates Gated Recurrent Units with Deep Deterministic Policy Gradient. The method optimizes control actions for stable power regulation in which the Gated Recurrent Units deal with temporal dynamics to rectify ramp rate discrepancies and power imbalances in multiport direct current converters. Experimental results demonstrate that the proposed model achieves an accuracy of 0.98 and a net output power of 72.1kW under variable conditions, ensuring efficient and stable operation at medium-scale power levels.
The paper analyses the pricing of various types of thermal coal on the international market in the period 2015-2025. Coal prices during this period fluctuated significantly under the influence of factors, such as: demand, supply, production costs and global events, e.g., the COVID-19 crisis, Russia's aggression against Ukraine and climate policies. The major benchmark is the price of Australian coal 6,000 kcal/kg (25 MJ/kg) quoted at the port of Newcastle (NEWC), which reflects market trends. During the period under analysis, prices went through three phases: stable, dynamic growth (2021-2022) and stabilization after the peak. The analysis covered the pricing of types with different calorific values, from 6,000 to 3,400 kcal/kg, and examined how changes in calorific value affect pricing. It was calculated that a decrease in calorific value by 1 MJ/kg causes a price change of approximately 6-7% (relative to the base price of coal: 6,000 kcal/kg), although in periods of high volatility this indicator was as high as 8-10%. The results confirm the stability of valuation methods over different periods, and indicate that the valuation of coal types with lower calorific value is proportional to the decrease in the energy content of coal. In summary, despite high price volatility, the relationship between the valuation of different quality coals is largely stable and based on energy parameters, which allows for a rational estimation of their value on the international market. A pricing formula has been proposed to calculate the prices of different coal types using the calculated price gradation coefficient.
The article analyzes the potential and marketing support for the development of bioenergy in Ukraine, taking into account European and world experience. It is determined that Ukraine has a significant bioenergy potential, which, however, is not fully realized due to a number of barriers. It is proven that one of the key problems is the ambiguous awareness of business and the population about the production of biofuels. Among large and medium-sized businesses in the agricultural and woodworking sectors, awareness is relatively high, while among the population, it remains limited. It has been determined that Ukraine has the potential of a raw material base for biofuels production, estimated at 22-25 mt of oil equivalent per year, of which the largest share is accounted for by agricultural residues. The main barriers to the development of biofuels production are identified, namely high initial investment, underdeveloped infrastructure, complex regulatory procedures, low awareness, and lack of qualified personnel. It is substantiated that in the context of post-war reconstruction and European legislation, decentralization of electricity production using modern energy technologies is absolutely necessary. It has been determined that to improve the marketing support for bioenergy development in Ukraine, the following priority areas have been identified: first and foremost, conducting information and educational campaigns to raise awareness among the public and businesses regarding the benefits and opportunities of bioenergy; followed by the development and implementation of effective financial instruments, such as soft loans, grants, and subsidies for relevant projects; and finally, the improvement of the regulatory framework by simplifying licensing procedures and establishing stable rules for investors.
The aim of this study is to analyze the impact of energy policy on economic security in European and Asian countries. The methodology includes a comparative analysis of energy policies across Europe and Asia, with a content analysis of legislative frameworks, statistical analysis of energy data, and case studies to assess the effectiveness of energy strategies in ensuring economic security. The key aspects of energy strategies, such as dependence on imported energy resources, the development of renewable energy, and energy efficiency, and how these factors influence economic stability, were compared. The study explores the experiences of European countries like Germany and France, Asian nations such as China and Japan, and Uzbekistan, which is actively improving its infrastructure. It was highlighted that the role of political decisions, investment in advanced technologies, and international cooperation plays in ensuring energy stability. Countries with diverse energy sources show greater resilience to economic crises and external political pressures compared to those with lower energy independence. The experiences of European, Asian countries, and Uzbekistan demonstrate that energy policy is a critical factor in economic security. Reliable and accessible energy sources are essential for stable economic growth. It was concluded that countries adopting innovative approaches in the energy sector, particularly through renewable energy development and energy-saving measures, can achieve long-term economic security. The results highlight the significance of adopting a strategic approach to energy policy as a crucial element in ensuring economic security in a globalized environment.
Energy-intensive industry plays a key role in the structure of greenhouse gas emissions in Poland and is one of the most difficult sectors to decarbonize in the energy transition process. The aim of this article is to identify and organize the main paths for decarbonizing energy-intensive industries in Poland in the context of striving for climate neutrality by 2050, with particular emphasis on the role of electrification, low- and zero-emission hydrogen, and synthetic fuels. The article is based on a review of current scientific literature, reports from international institutions, and strategic documents from the European Union and Poland. The first part presents the characteristics of energy-intensive industry in Poland compared to the European Union and the main structural conditions affecting the pace and scope of decarbonization. It then discusses the potential, limitations, and interrelationships of three key transformation pathways: direct electrification of industrial processes, the use of hydrogen as an energy carrier and raw material, and the development of synthetic fuels within the Power-to-X technology. The article shows that effective decarbonization of energy-intensive industries requires a portfolio approach, combining different technologies depending on the specific nature of the processes and sectors, as well as close coordination of energy and industrial policies.
The main goal of the research is to develop recommendations for innovations in the field of production efficiency, processing of agricultural raw materials for alternative energy, to analyze the technological indicators of individual resources involved in the biofuel production process, to study the effectiveness of alternative technological solutions for bioenergy energy projects, and possible ways of developing bioenergy in Ukraine in the post-war period. Significant depletion of agricultural land and, as a result, a significant decrease in the supply of humus and nutrients requires a review of the structure of the raw material base for bioenergy. It has been established that the level of energy consumption and energy income in the form of main and by-products depends on agricultural techniques for growing agricultural crops, their yield, the potential level of labor costs, fertilizers, energy carriers, and other production resources. The results of a study of the efficiency of using organic raw materials for biofuel production and the potential for using primary and secondary products of the agro-industrial complex in biogas production were obtained. The conducted studies showed that the optimal raw material for obtaining biogas is corn and other raw materials with minimal protein content and high carbohydrate content. The main result of the research is the establishment of parameters of the model of the dependence of energy production volumes on the energy value of the by-products of the processing of oilseeds, grain crops, fodder, and other resources involved in the process of biogas model the efficiency of biogas production.
Bioethanol is an alternative solution that fulfills the gasoline demand and directly reduces imports. It has similar characteristics to gasoline and is more sustainable because it is derived from biomass and has lower emissions. The research aims to assess bioethanol production to meet Indonesia's mandatory bioethanol utilization and to reduce imports until 2030 by accomplishing a system dynamic model of gasoline supply and demand in Indonesia. Using system dynamics software STELLA, the model will help us to understand the trend of supply-demand of gasoline in Indonesia with related variables, and with some scenarios, the simulation will be conducted to achieve particular goals. If no intervention exists in the modeled system, the gasoline import trend tends to grow yearly, reaching more than 70% of the total supply. The bioethanol mandate will be achieved when the Mandatory Scenario is used, which will be 20% blended with gasoline in 2025. The scenario will reduce gasoline imports to 4.13-10.39 million kL during the simulation period. Meanwhile, the Zero Gasoline Import Scenario will need 31.54-43.91 million kL of bioethanol, and the blending rate of bioethanol will be 71-76%. Therefore, the government should set an E75-E80 mandate if gasoline imports are to be abolished. Several policies that can support the scenario and be proposed to the government are also given, such as incentives for feedstock and bioethanol producers, price regulation for gasoline and bioethanol, and incentives for the customer and automotive manufacturers.
This study examines the influence of energy-efficient and environmentally sustainable components of sustainable development on the production of bioorganic fertilizer "Effluent", derived from the anaerobic digestion of pig manure in a biogas facility. The research focuses on its application in corn cultivation technologies to enhance crop yield and quality. The authors considered the technologies of using liquid manure as an organic fertilizer, which is currently the most rational way of directly applying it to the fields after preliminary anaerobic fermentation in biogas plants. This fertilizer has been found to contain a significant amount of macro-and microelements and beneficial microflora. The application of such fertilizers addresses the environmental aspect of livestock waste management, particularly from pig farms, contributes to the energy sector through biogas production, and mitigates economic and social challenges within the agricultural industry. The findings of this study confirm that optimizing plant nutrition through a balanced supply of macro-and microelements can significantly enhance productivity, improve product quality, and contribute to soil fertility. The use of the bio-organic fertilizer "Effluent", derived from digestate, presents a sustainable solution for the disposal of livestock waste from large industrial complexes, while simultaneously promoting the sustainable development of agriculture and local communities. This approach enables the production of organic plant and vegetable products while simultaneously managing livestock waste, optimizing the use of natural resources, reducing environmental pollution, and contributing to the nation's food and energy security as well as the sustainable development of rural areas.
Powering small biomedical and Internet-of-Things devices with piezoelectric harvesters is challenging because the available power is low, intermittent, and difficult to condition, which can actually overstress storage elements if charging is not adapted. This study evaluates lithium-ion battery longevity under such constraints using NASA PCoE datasets and designs charge policies matched to limited source power. Firstly, we examine temperature - voltage behavior, and identify a moderate operating window, which motivates a slow-charge baseline that reduces electrochemical stress. Secondly, we introduce two control layers: a dynamic, rule-based controller that derates current as terminal voltage approaches 4.2 V or temperature exceeds 24 degrees C within a defined safe window, and intelligent controllers (Random Forest, XGBoost, Gradient Boosting) that predict incremental degradation from routinely measured signals and select the current that minimizes expected damage under the same constraints. Using the number of cycles to SoH = 0.7 as the endpoint, dynamic control extends life from 30 to 43 cycles, while the intelligent controllers reach 45, 47, and 48 cycles. Reduced voltage peaks and ripple, together with lower thermal exposure, support the mechanism. Overall, aligning slow, condition-aware, and predictive charging with piezoelectric availability robustly extends service life and improves energy-capture efficiency, enabling more reliable, lower-maintenance biomedical and Internet-of-Things systems.
