Large-scale Renewable Energy Penetration Research Articles

Optimization Decomposition of Monthly Contracts for Integrated Energy Service Provider Considering Spot Market Bidding Equilibria

Under the current power trading model, especially in the context of the large-scale penetration of renewable energy and the rapid integration of renewable energy into the power system, reasonable medium- and long-term decomposition can reduce the fluctuation in the energy price when the integrated energy service provider (IESP) participates in the spot market. It helps to avoid the price risk of the spot market. Additionally, it promotes the optimization of the operation of the regional energy day-ahead scheduling. At the present stage, most of the medium- and long-term contract decomposition methods focus on the decomposition of a single power and take less consideration of the bidding space in the spot market. This limitation makes it challenging to achieve efficient interaction and interconnection among multi-energy resources and smooth integration between the medium- and long-term market and the spot market. To address these issues, this paper proposes an optimal monthly contract decomposition method for IESPs that takes into account the equilibrium of spot bidding. First, the linking process and rolling framework of multi-energy transactions between the medium- and long-term market and the spot market are designed. Second, an optimal decomposition model for monthly contracts is constructed, and a daily decomposition method for monthly medium- and long-term contracts that accounts for the spot bidding equilibrium is proposed. Then, the daily preliminary decomposition result of medium- and long-term multi-energy contracts is used as the boundary condition of the day-ahead scheduling model, and the coupling characteristics of the multi-energy networks of electricity, gas, and heat are taken into account, as well as the operational characteristics. Then, considering the coupling characteristics and operating characteristics of electricity, gas, and heat networks, the optimal scheduling model of a multi-energy network is constructed to minimize the sum of cumulative daily operating costs, and the monthly final contract decomposition value and daily spot bidding space are derived. Finally, examples are calculated to verify the validity of the decomposition model, and the examples show that the proposed method can reduce the variance in spot energy purchase by about 4.64%, and, at the same time, reduce the cost of contract decomposition by about USD 0.33 million.

Integration of Renewable Energy Power Plants on a Large Scale and Flexible Demand in Bangladesh's Electric Grid-A Case Study

The fundamental objective of this article is to put in renewable energy sources strategically within the context of Bangladesh's electric infrastructure. Solar and wind energy are inherently intermittent and variable, depending on weather conditions. Because of this unpredictability, power generation can fluctuate, making it difficult to maintain a consistent and reliable energy supply. The case study focuses on the problems and opportunities given by large-scale renewable energy power plant integration and the construction of a flexible demand system. The study digs into the technical, economic, and environmental elements of this integration, taking into account factors like as grid stability, fluctuation in energy supply, and the possibility for lowering greenhouse gas emissions. The abstract shows the potential benefits of such integration for Bangladesh's energy landscape and provides useful insights into the broader subject of renewable energy integration in poor countries through a thorough examination. This study can help future recommendations by policy-makers, producers, entrepreneurs, and utilities grow to enable for large-scale renewable energy penetration into the primary utility grid of a community by providing an outline of the energy supply difficulties in Bangladesh considering techno-economic advantages.

Synergistic development of heating system decarbonization transition and large-scale renewable energy penetration: A case study of Beijing

In response to climate change, China has set the target to achieve carbon neutrality by 2060. The large-scale development of renewable energy and the decarbonization transition of the heating system are crucial for achieving this target. Is there a synergistic effect between the heating system's decarbonization transition and the use of large-scale renewable energy sources? What effect does this synergistic development have on the CO₂ emissions and the economic costs of an energy system? This paper conducts a case study of Beijing, China, and designs three technical path scenarios for heating system decarbonization transition in the future, namely, business as usual scenario where existing policies and regulations are applied, the electricity substitution scenario where the traditional fossil fuel heating system is replaced by electric heat pump, and the synergistic development scenario where the existing thermal power units are retrofitted to replace the consumption of fossil fuels with renewable energy sources. Using the EnergyPLAN model, the hourly operation of Beijing's power and heating systems under the three scenarios are simulated. The research results are: Firstly, the proportion of local renewable energy will be over 70% in all three scenarios, and in the synergistic development scenario, the electricity and heating demand can be met by 100% renewable energy, reducing CO₂ emissions resulted from fossil fuel combustion; secondly, in view of the real-time match of power supply and demand in the power system, at times renewable energy supply would exceed demand. The rational use of the surplus renewable energy can promote further the synergistic development of decarbonization transition of heating system and renewable energy, reducing the primary energy consumption and CO₂ emissions by over 16% and 28% respectively in the future heating system; Thirdly to improve the economic benefit of a synergistic electric power and heating system, focus should be on the reduction of infrastructure construction cost rather than the reduction of fuel consumption. The proposed method can be extended to regional energy systems with more energy sectors, and can be used to formulate decarbonization transition schemes for industry, agriculture, etc.

Electrochemical Energy Storage and Conversion Systems – A Short Review

Electrochemical energy production systems – including fuel cells and electrolyzers – are vital technologies to address energy security and environmental demands. Also, their combination for improved performance is essential for future commercial applications. However, their real utilization (and integration with other alternative energy sources) goes beyond efficiency; large-scale penetration of renewable energy in the existing electrical grid systems is challenging due to destabilization possibility. Thus, electrochemical energy storage systems (e.g., electrochemical supercapacitors) are necessary for managing power generation intermittency and grid reliability. Therefore, this ultra-short review provides a brief overview of some of the most promising electrochemical devices for electrochemical energy production and storage for future systems in an engagement scenario.

Thermodynamic analysis of a hybrid cogeneration energy system based on compressed air energy storage with high temperature thermal energy storage and supercritical CO 2 Brayton cycle

The large-scale penetration of renewable energy leads to some imperative issues to the power grid. Energy storage technology is regarded as an effective method to solve these problems. In this paper, a hybrid cogeneration energy system based on compressed air energy storage system with high temperature thermal energy storage and supercritical CO2 Brayton cycle is proposed. A thermodynamic model of the system is established. Energy and exergy analysis are carried out based on a case study. It was found that under the design condition, the round trip efficiency of 58.66%, the energy storage density of 5.45 kWh/m3, and the overall exergy efficiency of 62.00% can be achieved. At the same time, the hot water about 88°C can be supplied. The influences of some key parameters on the performance are analyzed. It was found that the round trip efficiency is most sensitive to the outlet temperature of high temperature thermal energy storage system, isentropic efficiency of compressors and turbines, followed by the intercoolers effectiveness.

Detection of False Data Injection Attacks on Load Frequency Control System with Renewable Energy Based on Fuzzy Logic and Neural Networks

Load frequency control (LFC) system may be destroyed by false data injection attacks (FDIAs) and consequently the security of the power system will be impacted. High-efficiency FDIA detection can reduce the damage and power loss to the power system. This paper defines various typical and hybrid FDIAs, and the influence of several FDIAs with different characteristics on the multi-area LFC system is analyzed. To detect various attacks, we introduce an improved data-driven method, which consists of fuzzy logic and neural networks. Fuzzy logic has the features of high applicability, robustness, and agility, which can make full use of samples. Further, we construct the LFC system on MATLAB/Simulink platform, and systematically simulate the experiments that FDIAs affect the LFC system by tampering with measurement data. Among them, considering the large-scale penetration of renewable energy with intermittency and volatility, we generate three simulation scenarios with or without renewable energy generation. Then, the performance for detecting FDIAs of the improved method is verified by simulation data samples.

Optimal low‐carbon scheduling of integrated local energy system considering oxygen‐enriched combustion plant and generalized energy storages

Under the background of carbon neutrality and large-scale penetration of renewable energy, the integrated local energy system (ILES) has been extensively recognized as an effective way to reduce carbon emissions and improve renewable energy consumption level due to its high energy utilization and multiple energy complementarity. Hence, an optimal low-carbon scheduling model of ILES considering oxygen-enriched combustion plant (OECP) and generalized energy storages (GESs) is proposed in this paper to reduce the carbon emissions, improve the renewable energy consumption level and reduce the operating costs of ILES. More specifically, the cooperation mechanism between OECP and power to gas (P2G) is established to maintain a high carbon capture level during peak load periods; the GESs under the background of ILES is modelled, which can make full use of the multiple energy complementarity to improve the renewable energy consumption level of ILES. Case studies are performed on an IES that consists of an IEEE 33-bus distribution network, a 44-node district heating network and a 20-node natural gas network to verify the effectiveness and advantages of the proposed model.

Regional energy internet project investment decision making framework through interval type-2 fuzzy number based Choquet integral fuzzy synthetic model

With the rapid development of traditional energy system, the essential obstacles to the coordination between different energy sources is increasingly obvious, which greatly hinders the further improvement of energy efficiency. As a promising energy supply and consumption system, Regional Energy Internet (REI) has significant practical values in improving the coordination of traditional energy and promoting large-scale renewable energy penetration. Due to the large scale, high ambiguity and numerous key interactive criteria, the investment decision making of REI project is a key problem in application management, but it is challenging and has not been solved. Therefore, this paper explores a targeted and scientific REI investment decision making framework through the interval type-2 fuzzy number, Choquet integral and fuzzy synthetic evaluation model according to different preferences of investors to ensure the successful implementation and effective resources integration of potential REI projects. To verify the effectiveness of the framework, a case study with three typical REI projects simulated from a two-stage stochastic optimization model is studied, and corresponding investment countermeasures are proposed as a reference to allocate resources and prevent risk. Besides, since REI investment decision-making has not been deeply studied, this paper contributes to literature and expands knowledge.

A locational Marginal Price-Based Partition Optimal Economic Dispatch Model of Multi-Energy Systems

The large-scale penetration of renewable energy and deeply integrated multiple energy forms pose a major challenge for the accounting and allocation process of additional adjustment cost in multi-energy system and electricity market. The variable wind power and the operating status of multi-energy systems faced by the electricity market have driven researchers towards the decision of electricity spot market with complicated pricing mechanism. This paper presents a locational marginal price-based partition optimal economic dispatch model of multi-energy system with a high proportion of renewable energy. First, a model of the additional adjustment cost of multi-energy adjustable units to improve the power grid adjustment capacity is studied based on the power balance model of multi-energy conversion and storage. In the second, to improve the effectiveness of the ESM mechanism, an optimal economic dispatch model is established, with the goal of minimizing the additional adjustment cost of multi-energy adjustable units. Moreover, according to the characteristics of the model and the mechanism of locational marginal price-based economic dispatch, a solution method based on lagrangian relaxation is proposed. The incentive compatible locational marginal price is obtained. Finally, a simulation model of multi-energy systems based on IEEE 39-nodes power system and 7-nodes natural gas system is established. And the model is based on operating data of an actual grid with high proportion of renewable energy in Northeast China. The results of the examples show that the proposed method can effectively improve the efficiency and flexibility of multi-energy system. Another advantage of the proposed method is that the capabilities of the complementary multi-energy coordination can be promoted.

Non-invasive Power Load Monitoring Method Based on Cloud Edge Collaboration

With the large-scale penetration of renewable energy, the safe and stable operation of power grid and economic dispatch are facing great challenges. How to realize accurate perception of internal load characteristics of power users is an important technical difficulty to support power demand side management. For this reason, this article is based on extensive IOT technology in electricity, and a non-invasive power load monitoring method (NILM) based on cloud edge collaboration is proposed. Through the two-level architecture of “edge identification” and “cloud correction”, the method effectively overcomes the contradiction between the weak computing capability of edge terminal and the heavy communication pressure of cloud master station. The experimental results show that the method can effectively improve the accuracy and reliability of traditional NILM method by considering the influence of external factors.

Analysis of Economic-Technical Potential of Renewable Power Sources for the Establishment of National Renewable Energy Center in Ninh Thuan Province, Vietnam

Currently, Vietnam‘s energy source structure is being changed by which renewable energy sources play more important role to meet the electricity demand and reduce greenhouse gas emissions from fossil energy sources. Vietnam’s energy development strategy determines to build some renewable energy centers, of which Ninh Thuan is the first province designated to become a national renewable energy center. This is based on Ninh Thuan’s endowment as a province having the largest renewable energy potential in Vietnam. Development of a large renewable energy center allows power system planners to overcome the mismatch in timescales associated with developing transmission power grid and renewable energy generation. Besides, renewable energy center can facilitate a significant pipeline of large-scale renewable energy and storage projects. However, Ninh Thuan province is far away from the major load centers of Vietnam so the calculation and analysis of economic indicators need to be studied. This paper will present the results of the analysis of economic indicators of major renewable electricity sources in Ninh Thuan (onshore wind power, offshore wind power, solar power) to provide scientific arguments for developing a renewable energy center in Vietnam. Also the paper addresses the problem of the large-scale penetration of renewable energy into the power system of Vietnam. The proposed approach presents the optimization of operational decisions in different power generation technologies as a Markov decision process. It uses a stochastic base model that optimizes a deterministic lookahead model. The first model applies the stochastic search to optimize the operation of power sources. The second model captures hourly variations of renewable energy over a year. The approach helps to find the optimal generation configuration under different market conditions.

Multi-Objective Day-Ahead Scheduling of Power Market Integrated With Wind Power Producers Considering Heat and Electricity Trading and Demand Response Programs

The large-scale penetration of renewable energy, such as wind power, brings a lot of economic and environmental benefits to the grid, and it also causes hidden dangers in the reliability and security of the power system due to its uncertainty. As an effective demand-side management method, demand response has unique advantages in smoothing wind power fluctuations and mitigating grid pressure. This paper proposes a new model for the demand response aggregator (DRA) that includes both combined heat and power systems (CHPS) and energy storage devices. DRA can interact with the Independent system operator (ISO) through combined heat and power (CHP) units, energy storage devices, and the heat buffer tank to benefit from the electricity market and the thermal market simultaneously. At the same time, wind power producers (WPP) are modeled to turn wind power that was initially passively consumed into active market participants. The problem is modeled using an improved weighted method, which aims to take the diverse objectives of multiple market participants into account. The proposed model is tested on the modified IEEE RTS-24 test system to analyze the optimal scheduling strategies of each participant in the power market.

Grid Ancillary Services From Doubly Fed Induction Generator-Based Wind Energy Conversion System: A Review

Modern electrical grids face serious challenges to maintain healthy operational conditions. The nominal voltage and frequency, for instance, are affected by huge load changes and renewable energy integration. Renewable energy conversion systems are traditionally installed to provide active power. Fortunately, advanced renewable energy conversion systems have the ability to provide other facilities such as reactive power control and harmonic mitigation. In fact, recent grid codes obligate renewable energy systems to serve other duties such as generating reactive power rather than just simply supply active power, participate in fault ride through, for instance. This paper presents a comprehensive study on the doubly fed induction generator (DFIG)-based wind energy conversion system (WECS), which provides ancillary services to the grid along with performing its regular duties. These services include reactive power control, voltage ride through, power quality improvement, frequency control, and power oscillation damping. The literature survey and comparative studies show that the DFIG-based WECS has the ability to support electrical grid during normal and transient conditions, and it can also help in the large-scale renewable energy penetration to the power grid. The effect of different industrial and nonlinear controllers on DFIG performance in extracting grid ancillary services is highlighted.

Market-based participation of energy storage scheme to support renewable energy sources for the procurement of energy and spinning reserve

Energy Storage Scheme (ESS) is of great importance to realize energy management and to optimally utilize Renewable Energy (RE) integration in the electricity system. An increasing exploitation of RE in electricity system raises the concern about the need for Ancillary Services (AS) in a power system. These services are required for maintaining the reliability and security of the supply. This paper proposes a market-based participation of ESS to support large-scale RE penetration for the procurement of energy and AS using Virtual Power Plant (VPP) in a deregulated environment. The proposed VPP consists of a pumped-storage system as one of the recognized ESS and Renewable Power Producers (RPPs). This optimization problem is formulated and solved using an optimal power flow technique which considers network constraints and power flow limits. Spinning Reserve (SR) as one of the main AS is considered in this paper, which is procured under Spinning Reserve Market (SRM). The ability of the proposed approach to provide both energy and SR is tested on 3 case studies and demonstrated by considering a modified IEEE-30 bus test system. Results show that the VPPs can play a significant role in increasing the penetration of RE for the procurement of energy and AS.

Distributed cooperative optimal control architecture for AC microgrid with renewable generation and storage

AC microgrid is a promising approach to integrate various distributed generators and energy storage into the power system, and provide renewable and reliable energy to the customers. However, highly intermittent distributed energy sources and varying load demands pose increasing challenges for optimal energy management in an AC microgrid. In this paper, a distributed cooperative optimal control method based on the discrete consistency algorithm is proposed to realize the large-scale penetration of renewable energy in an AC microgrid. The proposed approach is implemented through a multi-agent distributed hierarchical control architecture, which only requires a local communication network to exchange the information. The optimal control is achieved through a three-level control architecture. The third control level aims at multi-objective optimal scheduling, considering the factors such as fuel consumption, pollution in the form of emissions and operational maintenance. The second control level is based on the discrete consistency algorithm that optimizes the frequency and voltage references of droop control and also shares the active and reactive power accurately according to the particular demand. The first control level is responsible for reference tracking of the associated components. Compared with the conventional centralized and decentralized controls, the proposed control method offers increased robustness and flexibility in the AC microgrid control, and only requires limited communication between neighboring agents to realize a global optimization. Finally, the effectiveness of the proposed strategy is verified in a typical AC microgrid model by using the PSCAD/EMTDC software.

An Improved Control and Energy Management Strategy of Three-Level NPC Converter Based DC Distribution Network

To meet the challenge of large-scale renewable energy penetration and take full advantage of existing AC infrastructure, the bipolar DC distribution system is of interest. In this article, the system structure and characteristics of the bipolar DC distribution network are proposed. The three-level Neural Point Clamped Converter (NPC) is used in the proposed system to construct the bipolar DC system. To optimize the DC system performance, an improved cooperative control and energy management strategy is proposed mainly to mitigate DC voltage fluctuation and balance the positive and negative phase voltage. The improved strategy consists of (1) 2-degree of freedom (2DOF) PID controller in traditional voltage control loop; (2) cooperative controller to take full advantage of storage system; (3) voltage equalization controller to balance two-phase voltages; and (4) the energy management system to dispatch the response job to batteries and supercapacitors. Experiments and simulations are performed to validate the effectiveness of the proposed strategy.

Renewable-energy developments in Arab countries: a regional perspective

This paper details the status of renewable-energy (RE) developments in Arab countries (AC) as an essential element for the sustainable economic development of these countries, despite their wealth in oil and gas. The paper first presents a review of the RE resources in AC and sheds light on some achieved and/or ongoing RE projects in the region. It also examines the adequacy of the present national institutions responsible for RE developments, and evaluates the effectiveness of work programmes of major regional and international organizations supporting RE activities. Finally, the paper identifies major obstacles hindering the large-scale penetration of RE into the energy markets of AC, and draws conclusions for increasing RE contribution to those markets.