Renewable Energy Sources Research Articles

Impact of grid strength on grid-forming inverter performance: a comparative study of droop and virtual synchronous generator controls

Abstract This study investigates the performance of grid-forming inverters under both strong and weak grid conditions, focusing on two widely used control strategies: droop control and Virtual Synchronous Generator (VSG) control. The increasing integration of renewable energy sources has necessitated the development of advanced inverter control techniques that can ensure stable operation in grids with varying strengths. To address this challenge, the research aims to compare the dynamic responses of droop and VSG-controlled inverters, particularly under disturbances such as frequency deviations, phase jumps, and voltage sags. The methodology involves detailed simulation of power system models representing both robust and weak grids, with parameters adjusted to reflect realistic operating conditions. The simulation results indicate that while droop control exhibits faster convergence under certain disturbances in strong grids, VSG control consistently provides smoother transitions and improved stability, especially under weak grid conditions, due to its inherent virtual inertia and damping characteristics. These findings show the potential of VSG-based control in enhancing grid resilience and stability in modern power systems with high renewable penetration.

Renewable Energy Source Integration With Intelligent Neuro‐Fuzzy Control for Microgrid System

Renewable Energy Source Integration With Intelligent Neuro‐Fuzzy Control for Microgrid System

Challenges and Emerging Trends in Hydrogen Energy Industrialization: From Hydrogen Evolution Reaction to Storage, Transportation, and Utilization.

Green hydrogen (H2) emerges as a sustainable alternative to fossil fuels, offering a clean method to store renewable energy through water electrolysis with high energy content and zero carbon emissions. While research largely focuses on specific aspects such as hydrogen evolution reaction (HER), seawater HER electrocatalysts, and electrolyzer development, these studies often overlook the broader hydrogen economy from an integrated industry chain perspective. This review bridges that gap by providing a comprehensive analysis of hydrogen energy industrialization, covering advancements in HER, seawater HER, and electrolyzers, all aim at enabling industrial-scale H2 production. It further explores innovations and challenges in hydrogen storage and transportation, as well as real-world projects spanning the green hydrogen supply chain. Additionally, life cycle assessment studies validate the environmental benefits of using renewable energy sources for green H2 production. Furthermore, this review highlights advancements in counter-oxygen evolution reactions and organic oxidation reactions, alongside strategies to mitigate competing chlorine evolution reactions. Through this comprehensive examination, this review aims to inform readers of the latest developments in hydrogen energy industrialization, explore its growth potential, and provide new insights to propel the hydrogen economy forward.

Improving frequency stability in grid-forming inverters with adaptive model predictive control and novel COA-jDE optimized reinforcement learning

The increasing utilization of renewable energy sources in low-inertia power systems demands advanced control strategies for grid-forming inverters (GFMs). Conventional Model Predictive Control (MPC) methods, which depend on static models and predefined boundaries, often struggle to preserve frequency stability in dynamic grid conditions. This research presents an Adaptive Model Predictive Control (AMPC) framework to enhance GFM performance in Virtual Synchronous Machine (VSM) mode, ensuring robust frequency stability under uncertainties. The primary issue addressed is the inefficiency of traditional MPC in adapting to dynamic grid conditions. To resolve this, the AMPC framework combines offline reinforcement learning for parameter tuning with online MPC using soft constraints. The offline phase employs a novel Hybrid Crayfish Optimization and Self-Adaptive Differential Evolution Algorithm (COA-jDE) to minimize the cost function , deriving optimal control parameters (Q, R) before real-time deployment. This process, termed cost function minimization using COA-jDE in a reinforcement learning framework, enhances GFM performance by adaptively adjusting virtual inertia and damping. Simulations on a 16MW wind-powered DFIG microgrid demonstrate that AMPC outperforms traditional MPC and VSM methods during grid disturbances, symmetrical faults, islanding, and load shifts. Furthermore, AMPC is computationally efficient compared to conventional reinforcement learning techniques, as adaptation is restricted to offline tuning. The framework not only improves compliance with grid codes (e.g., GC0137, IEEE 1547) but also provides a flexible, resilient control strategy for modern low-inertia grids.

Appropriate Switched Reluctance Generator for Wind Energy Domestic: Design and Electromagnetic Performance

This study explores the suitability of Switched Reluctance generators (SRGs) for domestic wind energy applications, focusing on design considerations and electromagnetic performance factors. The design aspects encompass rotor and stator configurations, integration with wind turbines, and material selection for durability and cost-effectiveness. Electromagnetic performance factors such as torque density, efficiency, power factor, and control system integration are crucial for optimizing energy conversion and system stability. Our goal is to enhance torque performance by carefully selecting the number of phases and varying combinations of stator and rotor pole numbers (specifically, 6/4, 8/6, and 12/8). To ensure a fair comparison, we maintain the same main dimensions across all topologies. This involves key parameters such as the inner and outer diameters of the stator, the height of the rotor poles, the air gap length, the stator pole height, the stack length, and the width of the stator yoke. Our analysis has revealed that increasing the extinction angle has a significant impact on the system's behavior. These observations highlight the intricate nature of the system's dynamics and stress. the need for careful optimization of these parameters to achieve superior performance. By addressing these factors, SRGs can serve as a dependable and efficient solution for producing wind energy in residential areas, thereby promoting. Greater access to renewable and sustainable energy sources for households.

Analysis of the Carbon Footprint of a Textile Company for the Automotive Industry

This study aims to develop a process to calculate the carbon footprint of a company in the textile sector for the automotive industry, thus addressing a research gap identified in this sector. Based on a structured calculation model, the project aspires to innovate by quantifying not only the greenhouse gas emissions at different stages of the company’s operations, including those generated by the consumed electricity and gas, but also the emissions related to external and in-house transportation and solid waste management. The approach includes the design of a specific calculator, capable of integrating variables such as energy consumption, transport and types of waste, analysing them in the light of recognised conversion factors. This tool not only allows for a detailed assessment of emissions but also supports strategic decision-making, guiding the implementation of more sustainable business practices. The results indicate that, considering the use of renewable energy sources, the company’s total emissions amount to approximately 18 thousand tonnes of carbon dioxide equivalent. On the other hand, considering non-renewable energy, purchased electricity accounts for 31 thousand megawatt-hours per year, corresponding to 5 thousand tonnes of carbon dioxide equivalent, with the twisting area being the largest consumer at 89% of total usage, followed by the dipping area. In terms of mobile combustion, raw materials contribute 1373 million tonnes of carbon dioxide equivalent, while finished products generate 1869 million tonnes of carbon dioxide equivalent. Among the most impactful variables, solid waste, and stationary combustion stand out as the main contributors. These findings highlight the need for concrete measures to mitigate climate change, such as transitioning from stationary natural gas combustion to green electric power; identifying companies with more suitable waste treatment solutions, process changes that reduce disposable, and easily substitutable materials; making use of green electricity; exploring alternative transport methods or combining different modes, such as using electric vehicles for short distances; and optimizing transport routes. These initiatives reinforce the company’s commitment to sustainable development goals and the promotion of responsible environmental practices.

A Metaheuristic Framework for Cost-Effective Renewable Energy Planning: Integrating Green Bonds and Fiscal Incentives

The integration of non-conventional renewable energy sources (NCRES) plays a critical role in achieving sustainable and decentralized power systems. However, accurately assessing the economic feasibility of NCRES projects requires methodologies that account for policy-driven incentives and financing mechanisms. To support the shift towards NCRES, evaluating their financial viability while considering public policies and funding options is important. This study presents an improved version of the Levelized Cost of Electricity (LCOE) that includes government incentives such as tax credits, accelerated depreciation, and green bonds. We apply a flexible investment model that helps to find the most cost-effective financing strategies for different renewable technologies. To do this, we use three optimization techniques to identify solutions that lower electricity generation costs: Teaching Learning, Harmony Search, and the Shuffled Frog Leaping Algorithm. The model is tested in a case study in Colombia covering battery storage, large- and small-scale solar power, and wind energy. Results show that combining smart financing with policy support can significantly lower electricity costs, especially for technologies with high upfront investments. We also explore how changes in interest rates affect the results. This framework can help policymakers and investors design more affordable and financially sound renewable energy projects.

Site Evaluation and Data Modeling for Renewable Energy Integration: A Case Study in Seville, Spain

With a focus to automation and optimization, this paper offers a methodical approach to site inspection and data modeling in renewable energy projects. Using solar photovoltaic (PV) panels, an air-source heat pump (ASHP), and battery storage, our team applied this approach to a case study of a residential building in Seville, Spain, obtaining a zero-emission energy system. The approach consists of a thorough investigation of renewable energy sources, including solar, wind, biomass, geothermal energy, and heat pumps, and then a thorough evaluation procedure to find the most appropriate energy solutions for buildings. Our results show how well photovoltaic panels combined with heat pumps reduce energy demand while nevertheless guaranteeing sustainability by means of a battery storage system for ongoing operation.

Enhancing Of Power Quality Issue in Utility Grid Using Dynamic Voltage Restorer (DVR)

Abstract—Power quality disturbances, such as voltage sags, harmonics, and flickers, are growing concerns due to the increas- ing integration of nonlinear loads and renewable energy sources. The Dynamic Voltage Restorer (DVR) is an effective solution that injects compensating voltage to maintain stable supply conditions. This paper explores DVR operation, design, and control strategies, including PI control, for real-time applications. The implementation of DVR enhances grid stability, reduces downtime, and improves energy efficiency. Future advancements, such as integration with smart grids, renewable energy, and AI- based controls, are also discussed to enhance DVR performance in modern power systems. Index Terms—component, formatting, style, styling, insert

Advances in Modeling and Optimization of Intelligent Power Systems Integrating Renewable Energy in the Industrial Sector: A Multi-Perspective Review

With the increasing liberalization of energy markets, the penetration of renewable clean energy sources, such as photovoltaics and wind power, has gradually increased, providing more sustainable energy solutions for energy-intensive industrial sectors or parks, such as iron and steel production. However, the issues of the intermittency and volatility of renewable energy have become increasingly evident in practical applications, and the economic performance and operational efficiency of localized microgrid systems also demand thorough consideration, posing significant challenges to the decision and management of power system operation. A smart microgrid can effectively enhance the flexibility, reliability, and resilience of the grid, through the frequent interaction of generation–grid–load. Therefore, this paper will provide a comprehensive summary of existing knowledge and a review of the research progress on the methodologies and strategies of modeling technologies for intelligent power systems integrating renewable energy in industrial production.

Performance Analysis of Control Valves for Supply–Demand Balance Regulation in Heating Stations

With the high penetration of renewable energy, the imbalance between heat supply and demand is becoming increasingly severe. Installing additional heat storage bypass pipelines in the heating network can significantly enhance the heat storage capacity of the system, and regulating the supply and demand balance of heat stations can achieve a stable heat supply for users. This paper proposes a heat storage bypass configuration scheme and a dual-valve-coordinated control system. Based on the control valves’ ideal and operational flow characteristics, this paper delves into the minimum and maximum control impedance mechanisms in control valves, analyzing their impact on operational performance. Aiming at the fluctuation in the water supply temperature in the secondary pipe network (dead zone of 1%), the influence of control valve parameters on the dynamic response was systematically analyzed. The optimal parameter-matching scheme of the bypass control valve and the heat exchange control valve was finally determined through an optimization analysis. We verified its correctness based on the measured engineering data. This study improves the stability and operational efficiency of the supply and demand balance and decoupling control of the heating heat exchange unit, thereby establishing a critical technical foundation for advancing the high-efficiency integration of renewable energy sources within urban energy systems.

Optimal Energy Solution for Multi Residential Buildings: Combining Grid Connected PV System with Demand Response and EV’s

ABSTRACT - As energy demands continue to rise in urban multi-residential complexes, the integration of renewable energy sources with smart grid technologies becomes essential for sustainable, cost-effective, and efficient energy management. This study proposes a comprehensive energy solution for multi-residential buildings by combining a grid-connected photovoltaic (PV) system with a storage battery, electric vehicles (EVs), and demand response (DR) strategies. The system achieves significant reductions in grid dependency, energy costs, and carbon emissions. Through MATLAB Simulink modelling the technical feasibility and performance benefits of such an integrated framework are clearly demonstrated. This work provides a solid foundation for future research and policy formulation in the domain of smart residential energy systems. Key Words: Grid-Connected PV System, Demand Response, Electric Vehicles (EVs), Vehicle-to-Grid (V2G), Smart Energy Management, Multi-Residential Buildings, Energy Optimization, Renewable Energy Integration.

UTILIZATION OF FILTERS AND OTHER METHODS FOR HARMONIC DISTORTION MITIGATION IN ELECTRICITY NETWORKS TIED TO RENEWABLE ENERGY SOURCES: A REVIEW

Harmonics in electrical power systems can be likened to virus in biological systems. They cause all manner of disturbances including damages to electrical appliances and utility equipment. It is unfortunate that harmonics cannot be totally eradicated from electrical networks. This suggests that they are inescapable but can be efficiently minimized. In circumstances when they are removed or decreased, if proper care is not provided, they may reappear. Because of the challenges connected with old energy sources, such as carbon emissions and other forms of pollution, world economies are shifting to greener and cleaner forms of energy known as renewable energy sources (RESs). RES in standalone or grid connected mode is also a major source of power quality problems such as harmonics. To overcome harmonic issues, passive filtering techniques were initially used. Then, due to the limitations of passive filters, active filtering techniques were used before the more recent use of hybrid harmonic active filtering strategies. Aside from the use of filters, several methods have been used to address harmonic-related difficulties. In this research, harmonic mitigation attempts in the last twenty-seven years are surveyed. The primary purpose is to demonstrate the strength and limitations of each strategy. This will help with their selection and application in specific scenarios for harmonic reduction.

Optimizing energy and load management in island microgrids for enhancing resilience against resource interruptions

The increasing integration of distributed renewable energy sources (RES), energy storage systems (ESS), electric vehicle (EV) charging stations, and demand response (DR) mechanisms has significantly enhanced microgrid deployment. However, the operational complexity and vulnerability of islanded microgrids to disruptions, especially during renewable energy fluctuations, pose critical challenges. Existing approaches primarily focus on minimizing operational costs or emissions but fail to simultaneously address load curtailment, voltage stability, and resilience under uncertain conditions. In this paper, we propose a novel resilience-oriented energy and load management framework for island microgrids, integrating a multi-objective optimization function that explicitly minimizes load curtailment, energy losses, voltage deviations, emissions, and energy procurement costs while maximizing the utilization of renewable energy sources. Unlike conventional models that separately optimize demand-side management (DSM), distributed generation (DG), EV charging/discharging, and ESS scheduling, our approach incorporates a coordinated control strategy that jointly optimizes these elements alongside reactive power compensation devices such as capacitors and shunt reactors. To effectively solve this high-dimensional, nonlinear problem, we employ the Multi-objective Moth Flame Algorithm (MOMFA), an enhanced metaheuristic evolutionary algorithm designed to handle complex trade-offs between cost, reliability, and resilience. The superiority of MOMFA over conventional optimization techniques such as Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and Grey Wolf Optimization (GWO) is validated through simulations on a realistic 33-node microgrid under various renewable energy outage scenarios. The results demonstrate that the proposed framework achieves a 60% reduction in voltage deviation, an 81% decrease in energy losses, and an 86% reduction in CO₂ emissions, while ensuring zero load curtailment, even under severe outage conditions. The proposed method offers a scalable, real-time implementable solution for microgrid operators seeking to enhance resilience against renewable energy intermittency and optimize energy utilization. This work significantly advances state-of-the-art microgrid energy management by providing a holistic, multi-objective, and resilience-driven optimization strategy.

Life cycle assessment of glass fibre versus flax fibre reinforced composite ship hulls

A comparative Life Cycle Assessment (LCA) was conducted between a recreational ship hull made of flax fibre-reinforced bio-based epoxy resin and a traditional ship hull made of glass fibre-reinforced polyester. Since small fibreglass boats pose an environmental problem after the end of life (EoL), the primary aim of this study was to evaluate the sustainability of the biocomposite material and identify recommendations for the future eco-design of recreational boats. The LCA study was developed according to the ISO 14,040 (ISO 14040, 2006), 14,044 (ISO 14044, 2006) methodology and the OpenLCA 2.0.4 software with the Ecoinvent v.3.9.1 database. Compared to the traditional one, the LCA of the biocomposite ship hull showed positive environmental impacts for all indicators except Terrestrial Ecotoxicity (TETP), which increased by 357% due to the use of fertilisers in flax production. Remarkably, the Global Warning Potential (GWP) decreased by 14%, the Human Toxicity Potential (HTP) diminished by 13%, and the Abiotic Depletion Potential (ADP) related to material resources was reduced by 75%. The sensitivity analysis shows that electricity consumption is the primary environmental impact driver for the FFRB ship hull. Thus, selecting renewable energy sources, such as solar or wind power, can significantly enhance sustainability. It is important to note that these impacts are influenced by the system and boundary conditions considered in the study. It was suggested that the local production of flax fibre and the use of recyclable bio-resin could improve the eco-design of the ship hull.

Battery Sizing Method for Microgrids—A Colombian Application Case

The introduction of renewable energy sources in microgrids increases energy reliability, especially in small communities that operate disconnected from the main power grid. A battery energy storage system (BESS) plays an important role in microgrids because it helps mitigate the problems caused by the variability of renewable energy sources, such as unattended demand and voltage instability. However, a BESS increases the cost of a microgrid due to the initial investment and maintenance, requiring a cost–benefit analysis to determine its size for each application. This paper addresses this problem by formulating a method that combines economic and technical approaches to provide favorable relations between costs and performances. Mixed integer linear programming (MILP) is used as optimization algorithm to size BESS, which is applied to an isolated community in Colombia located at Isla Múcura. The results indicate that the optimal BESS requires a maximum power of 17.6 kW and a capacity of 76.61 kWh, which is significantly smaller than the existing 480 kWh system. Thus, a reduction of 83.33% in the number of batteries is obtained. This optimized size reduces operational costs while maintaining technical reliability. The proposed method aims to solve an important problem concerning state policy and the universalization of electrical services, providing more opportunities to decision makers in minimizing the costs and efforts in the implementation of energy storage systems for isolated microgrids.

IOT Based Solar Dehydration System For Chilli Drying

Solar dehydration is an innovative technology that combines renewable energy sources with thermal storage to improve drying efficiency and product quality. This research focuses on developing an Internet of Things (IoT) -based solar dryer for drying chili peppers. The IoT technology enables users to remotely monitor system parameters on mobile phones using an IoT application. The study investigates the integration of solar dryers for agricultural products, specifically focusing on Dominican bananas. It demonstrates the effectiveness of solar-assisted drying systems in reducing moisture content and enhancing the quality of dried chilies by providing controlled and consistent drying conditions. The results highlight the economic and quality benefits of these dryers, although further research on scalability and environmental impact is needed. The system utilizes a DHT22 sensor, which communicates temperature and humidity data to a microcontroller unit (MCU) via a single-wire serial interface. The MCU, an ESP8266-based Node MCU, is programmed using the Arduino IDE to read sensor data and transmit it over Wi-Fi. By connecting the Node MCU to a local Wi-Fi network, it serves a web page displaying real-time temperature and humidity readings. Users can connect their mobile devices to the Wi-Fi network to monitor the system remotely. The solar dehydration system was tested for drying chili samples weighing 2 kg, 5 kg, and 10 kg. The drying times for these samples were 1 hour 15 minutes, 2 hours, and 3 hours 30 minutes, respectively. The system also calculated the humidity levels for each sample, which ranged from 38% to 47%. Additionally, the system monitored and recorded the intensity of solar radiation during the drying process.

Importance of policy for Energy System Policy Making Transformation using the WSM Method

The process of developing policies and laws that apply to energy the manufacturing, distribution, and consumption phases systems is known as energy system policy-making. Energy policies are important in directing the growth and evolution of energy systems, providing security of supply, promoting sustainability, and helping to mitigate climate change. Energy sector development is critical for societal advancement, economic prosperity, and environmental sustainability. It incorporates a wide range of potential energy sources such as nuclear power, energy from renewable sources, along with fossil fuels (including sunlight, breeze, water, as well as natural gas). To cut greenhouse gas emissions, battle climate change, and achieve an environmentally friendly and less costly energy future, the world must prioritize the transition to a more resilient and sustainable energy system. The formulation of energy system policy involves a variety of stakeholders, including governments, regulatory bodies, energy companies, industry groups, environmental protection organizations, and the general public. These stakeholders collaborate to establish the objectives of energy policy, develop strategies, and implement the plans. energy system policy is critical in combating climate change due to how it encourages the use all energy produced from renewable sources, efforts to improve energy efficiency, and low-carbon technology. in order to attain aggressive emission reduction targets, research in this sector can give knowledge on effective policy formulation, implementation tactics, and evaluation frameworks. as the world progresses approaching an economy with fewer greenhouse gases, it is critical to understand the causes, impediments, and consequences of the shift to cleaner energy. research can assist identify the optimum governance structures, market mechanisms, and regulatory frameworks for facilitating the changeover to renewable energy sources while achieving carbon reduction goals. access to affordable, dependable energy services is essential for socioeconomic development and the eradication of poverty. research has the potential to shed light on the financial plans and legislative frameworks that might increase access to energy, especially in neglected areas, while addressing concerns of poverty and inequality. In order for the energy system to keep up with technological advancement, policy makers must encourage the use of cutting-edge energy technology. research may give decision-makers knowledge about emerging technologies, prospective implications, and the regulatory frameworks necessary to promote their acceptance and integration into the energy system. In this research we will be using weighted sum method. Clean fossil fuel power generation, natural gas combined cycles (ngcc), integrated gasifier combined cycles (igcc), improved transmission and distribution systems, decentralized power-fuel cells, decentralized power-micro-turbines. Evaluation parameters: impact on energy and carbon intensity, impact on security, impact on energy security, status and technological potential, barriers to commercial use. Result: the WSM method of Ranking Energy System Policy Making in Natural Gas Combined Cycles (NGCC) is got the first rank whereas is the Decentralised Power-fuel Cells is having the Lowest rank. The WSM method of Ranking Energy System Policy Making in Natural Gas Combined Cycles (NGCC) is got the first rank whereas is the Decentralised Power-fuel Cells is having the Lowest rank.

Blending Nature with Technology: Integrating NBSs with RESs to Foster Carbon-Neutral Cities

Nature-based solutions (NBSs) offer a promising framework for addressing urban environmental challenges while also enhancing social and economic resilience. As cities seek to achieve carbon neutrality, the integration of NBSs with renewable energy sources (RESs) presents both an opportunity and a challenge, requiring an interdisciplinary approach and an innovative planning strategy. This study aims to explore potential ways of achieving synergies between NBSs and RESs to contribute to urban resilience and climate neutrality. Focusing on the railway station district in western Thessaloniki (Greece), this research is situated within the ReGenWest project, part of the EU Cities Mission. This study develops a comprehensive, well-structured framework for integrating NBSs and RESs, drawing on principles of urban planning and energy systems to address the area’s specific spatial and ecological characteristics. Using the diverse typologies of open spaces in the district as a foundation, this research analyzes the potential for combining NBSs with RESs, such as green roofs with photovoltaic panels, solar-powered lighting, and solar parking shaders, while assessing the resulting impacts on ecosystem services. The findings reveal consistent benefits for cultural and regulatory services across all interventions, with provisioning and supporting services varying according to the specific solution applied. In addition, this study identifies larger-scale opportunities for integration, including the incorporation of NBSs and RESs into green and blue corridors and metropolitan mobility infrastructures and the development of virtual power plants to enable smart, decentralized energy management. A critical component of the proposed strategy is the implementation of an environmental monitoring system that combines hardware installation, real-time data collection and visualization, and citizen participation. Aligning NBS–RES integration with Positive Energy Districts is another aspect that is stressed in this paper, as achieving carbon neutrality demands broader systemic transformations. This approach supports iterative, adaptive planning processes that enhance the efficiency and responsiveness of NBS–RES integration in urban regeneration efforts.

STATE REGULATION AS A TOOL FOR MINIMIZING INVESTMENT RISKS IN UKRAINE'S RENEWABLE ENERGY SECTOR: CHALLENGES AND PROSPECTS

The article aims to comprehensively analyze the crucial role of state regulation and policy in mitigating investment risks within Ukraine's renewable energy sources (RES) sector. The topicality is underscored by Ukraine's strategic goals of achieving energy independence, fulfilling its commitments under the European Green Deal and EU integration path, and the urgent need for massive investment to reconstruct its energy infrastructure, heavily damaged by the full-scale Russian invasion, ensuring a transition towards a greener and more resilient system. Attracting the necessary private capital amidst heightened geopolitical tensions and specific war-related threats presents a significant challenge, making the effectiveness of state de-risking policies critically important. The research methodology involves a systematic analysis of Ukrainian energy legislation, regulations, and strategic policy documents pertinent to the RES sector. It includes a critical evaluation of the historical evolution and practical implementation of support mechanisms, such as the feed-in tariff system and renewable energy auctions, analyzing their impact on market development and investor confidence. A qualitative assessment identifies and categorizes the diverse spectrum of investment risks – regulatory, market, financial, infrastructural, and particularly, war-related risks dominating the current landscape. The study synthesizes information to evaluate the coherence and effectiveness of state interventions in addressing these risks, especially in the context of the ongoing war and post-war recovery planning. The obtained results indicate that while Ukraine possesses significant RES potential, attracting sufficient investment has been hampered by persistent regulatory instability, including retroactive policy changes and significant payment arrears under the previous feed-in tariff scheme, which severely eroded investor trust even before 2022. Bureaucratic hurdles and grid connection bottlenecks remain substantial operational risks. The full-scale war introduced overwhelming physical security risks and market disruptions, demanding novel policy responses beyond traditional support schemes. The analysis reveals that existing regulatory frameworks are often insufficient to address the magnitude of current challenges, particularly regarding war risk mitigation. Effective state policy must simultaneously address legacy regulatory deficiencies and implement robust mechanisms, potentially involving international partnerships, to cover war-related risks and facilitate reconstruction efforts. The practical value of this research lies in providing evidence-based insights for Ukrainian policymakers, regulatory bodies, and government agencies involved in shaping the energy sector's future. It offers a structured understanding of the complex risk environment, informing the design of more predictable, stable, and effective regulatory frameworks and support schemes tailored to current realities. Furthermore, the findings can guide potential domestic and international investors in assessing opportunities and risks within Ukraine's RES market. The article contributes to the strategic discourse on Ukraine's sustainable energy transition and green recovery, highlighting the indispensable role of sound state regulation in leveraging private investment for rebuilding a secure and modern energy system aligned with European standards.