Power distribution networks at the distribution level are becoming more complex in their behavior and more heavily stressed due to the growth of decentralized energy sources. Demand response (DR) programs can increase the level of flexibility on the demand side by discriminating the consumption patterns of end-users from their typical profiles in response to market signals. The exploitation of artificial intelligence (AI) methods in demand response applications has attracted increasing interest in recent years. Particle swarm optimization (PSO) is a computational intelligence (CI) method that belongs to the field of AI and is widely used for resource scheduling, mainly due to its relatively low complexity and computational requirements and its ability to identify near-optimal solutions in a reasonable timeframe. The aim of this work is to evaluate different PSO methods in the scheduling and control of different residential energy resources, such as smart appliances, electric vehicles (... [more]

Recently, the integration of optimal battery dispatch and demand response has received much attention in improving DC microgrid operation under uncertainties in the grid-connect condition and distributed generations. However, the majority of prior studies on demand response considered the characteristics of global frequency variable instead of the local voltage for adjusting loads, which has led to obstacles in operating DC microgrids in the context of increasingly rising power electronic loads. Moreover, the consideration of voltage-dependent demand response and optimal battery dispatch has posed challenges for the traditional planning methods, such as stochastic programming, because of nonlinear constraints. Considering these facts, this paper proposes a model predictive control-based integrated voltage-based demand response and batteries’ optimal dispatch operation for minimizing the entire DC microgrid’s operating cost. In the proposed model predictive control approach, the binary... [more]

The need for environmentally benign portable energy storage drives research on organic batteries and catalytic systems. These systems are a promising replacement for commonly used energy storage devices that rely on limited resources such as lithium and rare earth metals. The redox-active TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl-4-yl) fragment is a popular component of organic systems, as its benefits include remarkable electrochemical performance and decent physical properties. TEMPO is also known to be an efficient catalyst for alcohol oxidation, oxygen reduction, and various complex organic reactions. It can be attached to various aliphatic and conductive polymers to form high-loading catalysis systems. The performance and efficiency of TEMPO-containing materials strongly depend on the molecular structure, and thus rational design of such compounds is vital for successful implementation. We discuss synthetic approaches for producing electroactive polymers based on conductive and n... [more]

In this study, the possibility of sector coupling with biological Power-to-Methane to support and stabilize the energy transition of the three major sectors of electricity, heat, and gas was addressed. For this purpose, the energy cell simulation methodology and the Calliope tool were utilized for energy system optimization. This combination provides detailed insights into the existing dependencies of consumers and fossil and renewable energy suppliers on a local scale. In this context, Power-to-Methane represents an efficient technology for quickly and effectively exploiting unused electricity potential for various sectors and consumers. It was found that, even in regions with low wind levels, this surplus electricity potential already exists and depends on various influencing factors in very different ways. The solar influence on these potentials was considered in connection with gas-fired cogeneration plants for district heating. It was found that the current heat demand for distric... [more]

An economic analysis of the implementation of the power-to-gas (PtG) system between 2030 and 2055 is presented at a large scale. The capacity of the PtG system is adapted to two scenarios in Spain (Bailera and Lisbona 2018), corresponding to growing scenarios of 1.73 and 1.36%/y of its electricity market. The total power capacity of the PtG system has been fixed to 12.7 and 3.84 GW, respectively, at the end of 2055. The levelized cost of storage (LCOS) of the implementation of PtG has been evaluated. Assuming uncertainties in the current cost projections for CAPEX and OPEX, LCOS estimations are between 136 and 686 EUR/MWh with a payback time of 16 years in the best scenario for a reference electricity purchase of 100 EUR/MWh and a CO2 penalty of 100 EUR/ton. A sensitivity analysis and the viability dependence versus energy purchase and CO2 penalty certificates is shown. This work sheds some light for the comparison of PtG implementation costs in comparison with other storage options, s... [more]

Traditional power grids are mainly based on centralized power generation and subsequent distribution. The increasing penetration of distributed renewable energy sources and the growing number of electrical loads is creating difficulties in balancing supply and demand and threatens the secure and efficient operation of power grids. At the same time, households hold an increasing amount of flexibility, which can be exploited by demand-side management to decrease customer cost and support grid operation. Compared to the collection of individual flexibilities, aggregation reduces optimization complexity, protects households’ privacy, and lowers the communication effort. In mathematical terms, each flexibility is modeled by a set of power profiles, and the aggregated flexibility is modeled by the Minkowski sum of individual flexibilities. As the exact Minkowski sum calculation is generally computationally prohibitive, various approximations can be found in the literature. The main contribut... [more]

As the world is keen on cleaner and sustainable energy, hydrogen energy has the potential to be part of the green energy transition to replace fossil fuels and mitigate climate change. However, hydrogen energy storage is a difficult task since physical storage in the form of compressed gas under high pressure is associated with safety issues. Another form of hydrogen storage is material-based storage, which is the safest way to store hydrogen energy in a particulate matter, known as metal hydrides. Metal hydrides can store hydrogen at room temperature and use less volume to store the same amount of hydrogen compared to classical gas tanks. The challenges with the metal hydrides reactor are their slow charging process and the requirement of proper thermal management during the charging process. In this study, a metal hydride reactor model is developed in COMSOL Multiphysics, and the associated heat transfer simulations are performed. The main objective of this research is to optimize th... [more]

Flexible supercapacitors are highly demanding due to their wearability, washability, lightweight property and rollability. In this paper, a comprehensive review on flexible supercapacitors based on conductive polymers such as polypyrrole (PPy), polyaniline (PANI) and poly(3,4-ethylenedioxtthiophne)-polystyrene sulfonate (PEDOT:PSS). Methods of enhancing the conductivity of PEDOT:PSS polymer using various composites and chemical solutions have been reviewed in detail. Furthermore, supercapacitors based on carbonized banana peels and methods of activation have been discussed in point. This review covers the up-to-date progress achieved in conductive polymer-based materials for supercapacitor electrodes. The effect of various composites with PEDOT:PSS have been discussed. The review result indicated that flexible, stretchable, lightweight, washable, and disposable wearable electronics based on banana peel and conductive polymers are highly demanding.

Vehicle-to-grid (V2G) has been identified as a key technology to help reduce carbon emissions from the transport and energy sectors. However, the benefits of this technology are best achieved when multiple variables are considered in the process of charging and discharging an electric vehicle. These variables include vehicle behaviour, building energy demand, renewable energy generation, and grid carbon intensity. It is expected that the transition to electric mobility will add pressure to the energy grid. Using the batteries of electric vehicles as energy storage to send energy back to the grid during high-demand, carbon-intensive periods will help to reduce the impact of introducing electric vehicles and minimise carbon emissions of the system. In this paper, the authors present a method and propose a V2G control scheme integrating one year of historical vehicle and energy datasets, aiming towards carbon emissions reduction through increased local consumption of renewable energy, off... [more]

Energy storage for medium- to large-scale applications is an important aspect of balancing demand and supply cycles. Hydropower generation coupled with pumped hydro storage is an old but effective supply/demand buffer that is a function of the availability of a freshwater resource and the ability to construct an elevated water reservoir. This work reviews the technological feasibility of hydropower generation and also pumped hydro storage and its geographical distribution around the world. There is also an emphasis on installations in the Middle East and North Africa (MENA) in terms of available capacity as well as past and future developments and expansions. A discussion is presented on a project taking place in the United Arab Emirates (UAE) in the Hatta region, which has a water reservoir that would be fit for utilization for pumped hydro storage applications. Once the project is commissioned in 2024, it will provide an estimated 2.06 TWh per year, helping the UAE achieve the goal o... [more]

The vehicle-to-grid concept emerged very quickly after the integration of renewable energy resources because of their intermittency and to support the grid during on-peak periods, consequently preventing congestion and any subsequent grid instability. Renewable energies offer a large source of clean energy, but they are not controllable, as they depend on weather conditions. This problem is solved by adding energy storage elements, implementing a demand response through shiftable loads, and the vehicle-to-grid/vehicle-to-home technologies. Indeed, an electric vehicle is equipped with a high-capacity battery, which can be used to store a certain amount of energy and give it back again later when required to fulfill the electricity demand and prevent an energy shortage when the main-grid power is limited for security reasons. In this context, this paper presents a comparative study between two home microgrids, in one of which the concept of vehicle-to-home is integrated to provide a case... [more]

Energy storage systems is expected to be utilized to cover the increased electrification of energy demands and to alleviate the electrical energy production from intermittent energy sources such as solar and wind. Aggregated and distributed battery energy storage systems may improve electricity grids operability and security by providing smart energy management options and efficient resources allocation. In this paper, battery storage at the secondary distribution level is explored. The investigation is based on the end-user energy demand behavior. As such, the electrical energy consumption patterns are measured and analyzed in a residential area. Measurements were collected and analyzed in order to record the customers’ behaviors aiming to reveal their differences and similarities. Following this, aggregated and distributed battery energy storage systems are computed based on the features of the measured electrical power consumption patterns aiming to estimate the factors that could p... [more]

Indonesia has vast solar energy potential, far more than needed to meet all its energy requirements without the use of fossil fuels. This remains true after per capita energy consumption rises to match developed countries, and most energy functions are electrified to minimize the use of fossil fuels. Because Indonesia has relatively small energy potential from hydro, wind, biomass, geothermal and ocean energy, it will rely mostly on solar for its sustainable energy needs. Thus, Indonesia will require large amounts of storage for overnight and longer periods. Pumped hydro comprises 99% of global energy storage for the electricity industry. In this paper, we demonstrate that Indonesia has vast practical potential for low-cost off-river pumped hydro energy storage with low environmental and social impact; far more than it needs to balance a solar-dominated energy system.

The construction of nanostructured materials for their application in electrochemical processes, e.g., energy storage and conversion, or sensing, has undergone a spectacular development over the last decades as a consequence of their unique properties in comparison to those of their bulk counterparts, e.g., large surface area and facilitated charge/mass transport pathways. This has driven strong research on the optimization of nanostructured materials for the fabrication of electrochemical devices, which demands techniques allowing the assembly of hybrid materials with well-controlled structures and properties. The Layer-by-Layer (LbL) method is well suited for fulfilling the requirements associated with the fabrication of devices for electrochemical applications, enabling the fabrication of nanomaterials with tunable properties that can be exploited as candidates for their application in fuel cells, batteries, electrochromic devices, solar cells, and sensors. This review provides an u... [more]

This paper presents a novel methodology for planning and operating biogas energy systems based on the transactive energy concept to determine multilevel operating regimes for distributed generation. The developed model is used to manage the production, storage, and dispatch of biogas energy systems to meet the load demands of the biogas producer and support the operation of the distribution network operator. An Integer Linear Programming (ILP) is fitted to optimize the biogas production of the biogas producer, including the operation of the biogas storage systems and their interaction with the network operator. The model’s objective is to maximize benefits for the participating agents in a transactive energy context. The model’s effectiveness is validated using seven case studies involving biogas systems having different operating ranges and modes to achieve enhanced flexibility and reliability for the system operation with a large proportion of intermittent energy resources. The simul... [more]

Energy storage (ES) is playing an increasingly important role in reducing the spatial and temporal power imbalance of supply and demand caused by the uncertainty and periodicity of renewable energy in the microgrid. The utilization efficiency of distributed ES belonging to different entities can be improved through sharing, and considerable flexibility resources can be provided to the microgrid through the coordination of ES sharing and demand response, but its reliability is affected by multiple uncertainties from different sources. In this study, a two-stage ES sharing mechanism is proposed, in which the idle ES capacity is aggregated on the previous day to provide reliable resources for real-time optimization. Then, a two-layer semi-coupled optimization strategy based on a deep deterministic policy gradient is proposed to solve the asynchronous decision problems of day-ahead sharing and intra-day optimization. To deal with the impact of multiple uncertainties, Monte Carlo sampling i... [more]

Research activity in the field of combined cooling heating power (or trigeneration) systems with high renewable energy source (RES) contributions has increased rapidly over the last few years, in line with the European Union legislation about energy communities. However, technical challenges arise regarding the synergetic, sustainable and optimal integration of RES in local energy systems. In the present study, the operation of a trigeneration system located in the student residences of Democritus University of Thrace in Greece is examined. The system involves a combination of highly promising renewable and storage technologies, including solar thermal energy and biomass for heat generation, hot water tanks for thermal energy storage, absorption refrigeration for cooling, along with Organic Rankine Cycle and photovoltaic systems for electricity generation. System modeling and simulation have been implemented in Dymola environment with the use of Modelica equation-based modeling languag... [more]

Energy-efficient and sustainable technologies are necessary to lower energy and carbon footprints. Many technologies are being pursued to meet the increasing energy demand in buildings. An attractive option is efficient utilization of available energy resources, including renewables, to support current and future building energy needs while targeting grid resiliency, energy, and environmental security at an affordable cost via on-site cogeneration-based approaches. This must include energy-efficient technologies with lower greenhouse gas emissions and optimized cost, performance, and reliability. This paper presents the economic and environmental benefits associated with power technologies such as thermionics and solid oxide fuel cells. Hybrid configurations consisting of heat pumps, power systems, and renewable photovoltaics in cogeneration and trigeneration modes of operation are presented. The role of such technologies in lowering CO2 emissions while improving energy resiliency and... [more]

Li-ion batteries are already being used in several applications, from portable devices to the automotive industry, and they represent a promising option also for other critical uses, such as in the storage of energy from renewable sources. However, two of the main concerns that still hinder their massive introduction in these further areas, are their safety and reliability. Depending on cell characteristics and operating conditions, the heat generated within the cell can exceed that dissipated from its surface, and the cell will fail, possibly with catastrophic consequences. To identify the hazardous working conditions of a cell, a simulation model including the main exothermic reactions was set up to investigate the onset of thermal runaway in several Li-ion cell configurations under various operating conditions. The behavior of four different cathodes under thermal abuse and the influence of external factors such as the environmental temperature and the cooling system efficiency were... [more]

The move towards a greener energy mix to fight climate change propels investments in converter-interfaced resources such as wind and photovoltaics, energy storage systems and electric vehicles. The ongoing evolution of the power system is occurring at a very fast pace, challenging transmission and distribution system operators to seek solutions that are not only adequate for this moment but also for future scenarios. Ongoing research in the fields of power electronics, power systems and control aims at developing control strategies that will help the energy transition to occur, while keeping a stable, secure and reliable power system. The objective of this paper is to present a critical review of the control strategies developed for grid-connected power converters found in renewable energy systems, energy storage systems and electric vehicles. The impact of grid-connected converters on the stability of power grids is also reviewed, highlighting the promising control strategies for enha... [more]

Energy storage has become increasingly important as a study area in recent decades. A growing number of academics are focusing their attention on developing and researching innovative materials for use in energy storage systems to promote sustainable development goals. This is due to the finite supply of traditional energy sources, such as oil, coal, and natural gas, and escalating regional tensions. Because of these issues, sustainable renewable energy sources have been touted as an alternative to nonrenewable fuels. Deployment of renewable energy sources requires efficient and reliable energy storage devices due to their intermittent nature. High-performance electrochemical energy storage technologies with high power and energy densities are heralded to be the next-generation storage devices. Transition metal chalcogenides (TMCs) have sparked interest among electrode materials because of their intriguing electrochemical properties. Researchers have revealed a variety of modifications... [more]

A review of different energy components is detailed, as a baseline of fundamentals for the new integrated energy concept idealization. This innovative solution is a Hybrid for Renewable Energy Network (Hy4REN) based on well-studied elements to produce the best final solution. This proposal has the objective of improving energy system sustainability, facing fossil fuel and climate change restrictions, and increasing energy network flexibility. The most mature energy storage technology, pumped hydropower energy storage (PHES), is used to support both the grid connection and stand-alone modes, as an integrated hybrid energy system. The hybrid system idealization is modular and scalable, with a complementary nature among several renewables, using sea water in offshore mode to build an integrated solution. By evaluating a variety of energy sources, complemented with economic analysis, the benefits associated are evidenced using this sustainable methodology based only on renewable sources. C... [more]

Groundwater storage is an important water management solution that is overlooked by several countries worldwide. This paper evaluates the potential for storing water in the Bananal sedimentary basin and proposes the construction of canals to reduce sediment obstructions in the river flow and harmful flood events. This would allow for better control of the water level. The water stored in the sedimentary basin can be used as a climate change adaptation measure to ensure that the level of the flood plain is maintained high during a drought or low during an intense flood event. Additionally, the flood plain will function as a water reservoir, regulate the river flow downstream from the flood plain, and enhance hydropower generation. A significantly smaller reservoir area is expected to store water, as the water will be stored as groundwater in the sedimentary basin. Results show that the Bananal basin has the potential to store up to 49 km3 of water, which can add up to 11.7 TWh of energy... [more]

As many new devices and factors, such as renewable energy sources, energy storage (ESs), electric vehicles (EVs), and demand response (DR), flood into the distribution network, the characteristics of the distribution network are becoming complicated and diversified. In this study, a two-layer collaborative optimized operation model for the multi-character distribution network considering multiple uncertain factors is proposed to achieve optimal dispatching of ES and EV and obtain the optimal grid structure of the distribution network. Based on basic device models of distribution network, the upper layer distribution network reconfiguration (DNR) model is established and solved by the particle swarm optimization (PSO) based on the Pareto optimality and the Prim algorithm. Then, the lower layer optimal dispatching model of ES and EV is established and solved by the binary PSO. The upper layer model and the lower layer model are integrated to form the collaborative optimized operation mod... [more]

This paper presents a method for supplying stable electricity using renewable energy sources and energy storage systems (ESSs) in a small-scale microgrid (MG) such as an island. Traditional control methods, such as master−slave control and droop control, have focused on equalizing power sharing among a small number of generators and do not deal well with emergencies such as unplanned generator failures. This paper proposes a control method that can stably maintain the frequency of the MG in various situations by combining the advantages of master−slave control and droop control and complementing the disadvantages. Simulations were performed under various conditions to verify the proposed control method.