Different Types Of Renewable Energy Sources Research Articles

Synthesis Load Model With Renewable Energy Sources for Transient Stability Studies

Increased penetration of renewable energy sources (RES) has brought challenges to load modelling techniques. This paper proposes a synthesis load model with RES (SLMR), and elaborates related industrial practice conducted by China Electric Power Research Institute. Several practical issues are addressed in designing and implementing SLMR, such as load survey and representation of different types of RESs. Besides, three new modelling concerns brought by RESs are novelly addressed in the paper, i.e., aggregation of various RES parameters, consideration of various RES terminal voltage, and additional line loss due to RES response. Parameterization of the SLMR calibrates widely varied node voltage in distribution grid, and aggregates them to one equivalent node. The proposed SLMR is practically applied in industrial works, which is demonstrated in the paper.

A New Decision-Making Strategy for Techno-Economic Assessment of Generation and Transmission Expansion Planning for Modern Power Systems

Planning for the intensive use of renewable energy sources (RESs) has attracted wide attention to limit global warming and meet future load growth. Existing studies have shown that installing projects such as transmission lines, energy storage systems (ESSs), fault current limiters, and FACTs facilitate the integration of RESs into power systems. Different generation and transmission network expansion planning models have been developed in the literature; however, a planning model that manages multiple types of projects while maximizing the hosting capacity (HC) is not widely presented. In this paper, a novel planning framework is proposed to enhance and control the HC level of RESs by comparing various kinds of renewables, ESSs, fault current limiters, and FACTs to choose the right one, economically and technically. The proposed problem is formulated as a challenging mixed-integer non-linear optimization problem. To solve it, a solution methodology based on a developed decision-making approach and an improved meta-heuristic algorithm is developed. The decision-making approach aims to keep the number of decision variables as fixed as possible, regardless of the number of projects planned. While an improved war strategy optimizer that relies on the Runge-Kutta learning strategy is applied to strengthen the global search ability. The proposed decision-making approach depends primarily on grouping candidate projects that directly impact the same system state into four separate planning schemes. The first scheme relies on the impedance of devices installed in any path to optimally identify the location and size of the new circuits and the series-type FACTs. The second scheme is based on optimally determining the suitable types of ESSs. On the other hand, the third scheme optimizes the reactive power dispatched from the ESSs and shunt-type FACTs simultaneously. The fourth scheme is concerned with regulating the power dispatched from different types of RESs. All of the simulations, which were carried out on the Garver network and the 118-bus system, demonstrated the ability of the investigated model to select the appropriate projects precisely. Further, the results proved the robustness and effectiveness of the proposed method in obtaining high-quality solutions in fewer runs compared to the conventional method.

ІНВЕСТИЦІЇ У ВІДНОВЛЮВАЛЬНУ ЕНЕРГЕТИКУ ЄС: ОЦІНКА ЕФЕКТИВНОСТІ СТИМУЛІВ

This study uses panel data regression analysis to examine the relationship between incentive policies and the deployment of renewable energy sources (RES) in the European Union (EU). Data for 25 EU countries were collected from 2000 to 2021, with Malta and Cyprus excluded due to insufficient data. A fixed effects model was utilised to consider individual country characteristics and unobservable factors that differ over time. Additionally, a dynamic panel data model was estimated to assess the influence of prior RES capacity on current capacity, offering more efficient parameter estimates than traditional static fixed-effect estimation. Our findings reveal the multidirectional impact of various RES incentive instruments and policies on different types of RES in the EU. Fiscal and financial instruments, such as taxes, grants, and R&D policies, proved more effective in promoting RES development than other incentive types in the energy sector. Market-based incentives, including certificates and support policy frameworks, also positively impacted the capacity of RES power plants. However, net metering, direct investment, and loans did not significantly increase RES, while regulation and direct investment appeared to constrain RES potential. The dynamic panel data estimates demonstrate that previous RES capacity positively and significantly influences current capacity. Furthermore, our estimation results emphasise that fossil energy consumption, nuclear energy, and GDP are critical determinants of RES development. Interestingly, net imports (energy security) and CO2 emissions were not significant factors driving RES growth. The results also indicate that the fossil fuel lobby could be more highly effective, and concerns about nuclear power are quite strong in the analysed countries. This study highlights the importance of RES incentive instruments that reduce investment costs for the success of RES mechanisms, stressing the need for supportive policies to enhance the competitiveness of renewable energy technologies. It emphasises that although some incentive policies have effectively promoted RES development, others, such as net metering, direct investment, and loans, have not achieved the desired results. In conclusion, understanding the effectiveness of various incentive instruments and policies is crucial for driving further RES development and improving the overall sustainability of the energy sector in the EU.

Developing a Marine Predator Algorithm for Optimal Power Flow Analysis considering Uncertainty of Renewable Energy Sources

Optimal power flow (OPF) is a crucial issue to maintain the reliable operation of power systems. However, achieving this objective is not easy, especially when renewable energy sources (RESs) are penetrated into the power system due to their uncertainty nature. This paper provides an optimal solution for the power flow problem including two different types of RESs based on a marine predator algorithm (MPA). The OPF model used in this paper has three different types of energy resources (thermal, wind, and solar). The output power from wind or solar generator has two probabilities either underestimation or overestimation consequently. These two probabilities have been translated into the objective function by two extra costs, penalty cost, and reserve cost, respectively. To check the validity of the proposed algorithm, it is applied to a modified IEEE-30 and IEEE-57 bus systems. The obtained results are compared with some recent optimization methods. The results show the effectiveness of marine predator algorithm in providing the optimal solution for the power flow problem with maintaining the power system constraints inviolate.

Public Attitudes toward Renewable Energy in Croatia

Renewable energy sources (RES) play a key role in achieving the European Union’s energy and climate objectives. As a member of the European Union, Croatia has committed to adopting European Directive 2009/28/EC, a directive on promoting the use of RES. Croatia shows good potential for the use of different types of RES. In the period 2009–2019, the share of renewable energy in energy consumption increased from 23.6 to 28.5 percent. The Croatian energy strategy aims to increase the national share of renewable energy to at least 32 percent by 2030. Acceptance and public support are essential for renewable energy to be introduced into energy policy and particularly to encourage renewable energy implementation in the residential sector. The purpose of the paper is to explore the public perception of renewable energy and citizens’ willingness to pay for the use of RES. Data were collected through a 2021 survey of citizens 18 years and older. The survey results show a low level of implementation of RES technology in the residential sector; more than 80 percent of respondents did not use any sources of renewable energy in their households. Results related to respondents’ knowledge of different sources of renewable energy suggest they have the most knowledge of solar, wind, and hydropower energy. Respondents believe that combating climate change, reducing dependency on energy imports, reducing environmental impacts, and improving health are the most important benefits of RES implementation. The survey reveals general support for RES among respondents; almost 89 percent of them would purchase renewable energy from local suppliers. In addition, 79 percent of survey participants were willing to pay for the introduction of RES technology into their households. The research shows that environmental concerns are the primary reason for citizens’ higher willingness to pay for RES.

RES and ES Integration in Combination with Distribution Grid Development Using MILP

In the paper, a new method of long-term planning of operation and development of the distribution system, taking into account operational aspects such as power flows, power losses, voltage levels, and energy balances, is presented. The developed method allows for the allocation and selection of the power of Renewable Energy Sources (RES), control of energy storage (ES), curtailing of RES production (EC), and the development of the distribution grid (GD). Different types of RES and loads are considered, represented by generation/demand profiles reflecting their typical operating conditions. RES allocation indicates the node in the distribution system and the power level for each type of RES that may be built. Energy storage (ES) allows generation to be transferred from the demand valley to the peak load. Curtailment of RES generation indicates the moment and level of power by which generation will be reduced, while the grid development (GD) determines between which network nodes a new power line should be built. All these activities allow to minimize the costs of planning work and development of the distribution system at a specific level of energy consumption from RES in the analyzed distribution system using a Mixed Integer-Linear Programming (MILP).

Future Greener Seaports: A Review of New Infrastructure, Challenges, and Energy Efficiency Measures

Recently, the application of renewable energy sources (RESs) for power distribution systems is growing immensely. This advancement brings several advantages, such as energy sustainability and reliability, easier maintenance, cost-effective energy sources, and ecofriendly. The application of RESs in maritime systems such as port microgrids massively improves energy efficiency and reduces the utilization of fossil fuels, which is a serious threat to the environment. Accordingly, ports are receiving several initiatives to improve their energy efficiency by deploying different types of RESs based on the power electronic converters. This paper conducts a systematic review to provide cutting-edge state-of-the-art on the modern electrification and infrastructure of seaports taking into account some challenges such as the environmental aspects, energy efficiency enhancement, renewable energy integration, and legislative and regulatory requirements. Moreover, the technological methods, including electrifications, digitalization, onshore power supply applications, and energy storage systems of ports, are addressed. Furthermore, details of some operational strategies such as energy-aware operations and peak-shaving are delivered. Besides, the infrastructure scheme to enhance the energy efficiency of modern ports, including port microgrids and seaport smart microgrids are delivered. Finally, the applications of nascent technologies in seaports are presented.

Optimum Modified Fractional Order Controller for Future Electric Vehicles and Renewable Energy-Based Interconnected Power Systems

Several issues have been risen due to the recent vast installations of renewable energy sources (RESs) instead of fossil fuel sources in addition to the replacement of electric vehicles (EVs) for fuel-powered vehicles. Mitigating frequency deviations and tie-line power fluctuations has become driving challenge for the control design of interconnected power systems. RESs represent continuously varying power generators due to their nature and dependency on the environmental conditions. In this context, this article presents a new modified hybrid fractional order controller for load frequency and EVs control in interconnected power systems. The new controller combines the benefits of two widely employed fractional order controllers, including the FOPID and TID controllers. In addition, a new practical application of recent artificial ecosystem optimization (AEO) method has been proposed in this article for determining simultaneously the optimum controller parameters. The proposed controller and optimization method are validated on two areas interconnected power system with different types of RESs and with considering the natural characteristics of sources, EVs and load variations. Obtained simulation results verify the superior performance of the proposed controller and optimization method for achieving high mitigation of frequency fluctuations and tie-line power deviations, increased robustness, enhanced system stability over a wide range of parameters uncertainty and fast response during transients.

Reliability Evaluation and Financial Viability of an Electricity Power Micro-Grid System With the Incorporation of Renewable Energy Sources and Energy Storage: Case Study of KwaZulu-Natal, South Africa

The increase in the demand for a reliable electricity supply by the utilities and consumers has necessitated the evaluation of the reliability of power systems. A reliable electricity supply is characterized by no or minimal duration and frequency of supply outages. This has triggered the necessity of using renewable energy sources (RESs) with optimization methods for reliability improvement of electricity systems and reduction of greenhouse gas (GHG) emissions. The main objective of this study is to optimize micro-grid systems operations, improve reliability, reduce emissions and balance the demand and supply of energy through RESs and battery energy storage system (BESS). The adaptive model predictive control (AMPC) method is used to address the issues of micro-grid operation. The AMPC algorithm solves the optimization problem of disturbance prediction in a micro-grid with different types of RESs and BESS integration. This optimization problem considers different constraints for minimum operating costs in different case scenarios. The financial viability of the proposed method is investigated. Solar photovoltaic (Solar PV), wind plant (WP) and BESSs are used with the AMPC method to investigate the impacts of annual real interest rates on cost and emission parameters, quantification of the emission oxides from different case scenarios, reduction of the cost of electricity (Ccoe), and power system reliability improvement. A modified Roy Billinton Test System (RBTS) is used to confirm the reliability enhancement and financial feasibility of the system. Case studies are used to confirm the proposed methods using climatic data for the city of Pietermaritzburg (29.37°S and 30.23°E), South Africa. The results obtained establish that the incorporation of RESs and BESSs using the AMPC method gives satisfactory outcomes.

Research on Seasonal Calculation Method of Renewable Energy Certificate Price

Introduction Based on the trend of consuming renewable energy sources （RES） through the market-based trading model， the “market electricity price + renewable energy certificate （REC） revenue” will become the main operation of energy generators in the future. Based on the research background of RES participating in spot power market， this paper studies the price of REC. Method Based on the optimized clearing model of the spot electric energy market， applying the theory of the life cycle costing （LCC） of RES generation and satisfying the internal rate of return （IRR） of the energy generators， we established the optimization model of coupling REC-electric energy market. Combined with the seasonal output characteristics of RES， the simulation and measurement methods of the seasonal curve and fluctuation interval of REC price are proposed. Result The price of REC for different types of RES are different， and the price of REC for different types of RES also has different climatic correlations. Conclusion Scientific and reasonable calculation of REC price can not only help RES generation enterprises make income assessment and more accurate investment decisions， but also provide relevant decision-making support for power market entities and trading centers.

Regional Area Protection Scheme for Modern Distribution System

More and more renewable energy sources (RESs) are integrated into the grid with inverter interfaces, which brings new challenges to protection systems. This paper proposes a directional overcurrent relay-based regional area protection scheme (RAPS) for a modern distribution system incorporating high penetration of RESs. Protection components and the sensitivity-preferred setting principle utilized in local relays are presented. Then, a RAPS is proposed to accelerate fault isolation and enhance protection coordination. It is achieved by exchanging the pick-up signal and fault direction information from local relays within each predefined regional area. Breaker tripping or relay holding decisions are made by several RAPS criteria. The effectiveness of the protection scheme is verified by the simulation of a modified IEEE 34-node distribution system with different types of RESs. Simulation results validate that the selectivity, and speed of protection system can be improved by this scheme. Compared to existing protection schemes for the distribution system with RESs, the proposed scheme can be applied in complicated scenarios, such as partial loss of communication or failure of a local relay.

An optimization model for design and analysis of a renewable energy supply system to the sustainable rural community

The goal of this paper is to present a new optimization framework for design and analysis of a stand-alone energy supply system to rural communities using 100% renewable energy sources (RES). In achieving this goal, we first propose a technology superstructure for energy supply. The superstructure starts from different types of RES which are easily available in rural communities, including solar, wind, organic waste, and lignocellulose biomass. The RESs are processed in multiple technologies to meet energy demands of a rural community (chemical, thermal and electric powers). Using the model we identify the optimal system configuration and practical operational strategies.

Возобновляемая энергетика в ЕС: смена приоритетов

The article analyses the EU policies of promoting renewable energy sources (RES), including the role of state subsidizing and the change of EU policy in 2013. First EU actions in this area were implemented in late 1990s. In mid 2000s the European Commission developed integrated approach of the encouragement of renewables. Promotion of RES was integrated with other areas of the EU energy policies in the framework of the Climate and Energy Package in 2007. The paper evaluates EU achievements and development of particular types of RES in the EU in 2000s. A comprehensive comparative analysis of the cost of different types of RES and the use of incentive measures in the European Union and EU member states is carried out. The conclusion is made that despite the impressive technological progress the renewable energy, with rare exception, is still uncompetitive with the traditional sources of energy in terms of costs. A large-scale state support was the reason for the rapid development of renewables in the EU. Article investigates distorting effects of RES subsidies on the market price of electricity. Feed-in tariffs, investment grants, quotas and tax benefits were the most widespread forms of direct and indirect RES subsidies in the EU. During the economic crisis, these subsidies have become a heavy burden for the budgets of the EU countries and population. Now the EU is modifying its strategy on RES in order to reduce the volume of subsidies. In 2013 European Council substantially changed the priorities of the EU energy policies: instead of «sustainable energy» it accentuated the need to provide a “competitive energy”. Strategic decision to reform the existing methods of RES subsidizing and to develop an «economically reasonable» support scheme was made. The reduction of subsidies will inevitably lead to a sharp reduction in the rate of growth of renewables and the failure to achieve previously agreed EU targets.