Integration Of Storage Systems Research Articles

Multiobjective formulation of the integration of storage systems within distribution networks for improving reliability

A new approach to improve reliability in distribution networks using energy storage systems is presented in this paper. Electric utilities have been using switching devices in distribution networks mainly to improve network reliability considering sustained interruptions. Temporary interruptions have been relegated to second place. However in modern societies appliances with electronic components are becoming more sensitive to temporary interruptions. Because of this, reliability indexes like the Momentary Average Interruption Frequency Index (MAIFI) that considers temporary interruptions are receiving more attention by electric utilities. The integration of storage systems into the multiobjective planning of distribution networks is proposed in this paper, to improve the reliability index MAIFI. This approach considers the optimization of storage systems integrated in a problem with multiple objective functions. The reliability index MAIFI is the first objective function, minimized by optimally choosing the size and location of battery banks in the distribution network. The second objective function, System Average Interruption Frequency Index (SAIDI) is optimized by finding the optimal number and location of switching devices. The third objective function consists on the minimization of the equipment cost. The optimization of these conflicting functions is achieved by the use of the Non-Dominated Sorting Genetic Algorithm II (NSGA-II).

Integration of compressed air energy storage systems co-located with wind resources in the ERCOT transmission system

In this paper, we investigate optimal locations and capacity for integrating storage systems in the electric transmission grid to improve wind power production. The impacts on wind power production and conventional thermal generation due to operation of utility-scale storage systems are simulated. A compressed air energy storage (CAES) is chosen as an utility-scale storage technology, which can provide several hundred MWs of electric power. A mixed integer programming (MIP) is implemented for the mathematical formulation. The Electric Reliability Council of Texas (ERCOT) wind, load data and its simplified transmission system are used for a case study. To mandate wind power production, we apply 20% goal for renewable portfolio standard (RPS). Operation of 1350MW CAESs improves wind power production and RPS target achievements, however, thermal generation does not significantly decrease under the given simulation condition.

Integration of Lithium-Ion Battery Storage Systems in Hydroelectric Plants for Supplying Primary Control Reserve

The ever-growing diffusion of renewables as electrical generation sources is forcing the electrical power system to face new and challenging regulation problems to preserve grid stability. Among these, the primary control reserve is reckoned to be one of the most important issues, since the introduction of generators based on renewable energies and interconnected through static converters, if relieved from the primary reserve contribution, reduces both the system inertia and the available power reserve in case of network events involving frequency perturbations. In this scenario, renewable plants such as hydroelectric run-of-river generators could be required to provide the primary control reserve ancillary service. In this paper, the integration between a multi-unit run-of-river power plant and a lithium-ion based battery storage system is investigated, suitably accounting for the ancillary service characteristics as required by present grid codes. The storage system is studied in terms of maximum economic profitability, taking into account its operating constraints. Dynamic simulations are carried out within the DIgSILENT PowerFactory 2016 software environment in order to analyse the plant response in case of network frequency contingencies, comparing the pure hydroelectric plant with the hybrid one, in which the primary reserve is partially or completely supplied by the storage system. Results confirm that the battery storage system response to frequency perturbations is clearly faster and more accurate during the transient phase compared to a traditional plant, since time delays due to hydraulic and mechanical regulations are overpassed. A case study, based on data from an existing hydropower plant and referring to the Italian context in terms of operational constraints and ancillary service remuneration, is presented.

Equivalence of Primary Control Strategies for AC and DC Microgrids

Microgrid frequency and voltage regulation is a challenging task, as classical generators with rotational inertia are usually replaced by converter-interfaced systems that inherently do not provide any inertial response. The aim of this paper is to analyse and compare autonomous primary control techniques for alternating current (AC) and direct current (DC) microgrids that improve this transient behaviour. In this context, a virtual synchronous machine (VSM) technique is investigated for AC microgrids, and its behaviour for different values of emulated inertia and droop slopes is tested. Regarding DC microgrids, a virtual-impedance-based algorithm inspired by the operation concept of VSMs is proposed. The results demonstrate that the proposed strategy can be configured to have an analogous behaviour to VSM techniques by varying the control parameters of the integrated virtual-impedances. This means that the steady-state and transient behaviour of converters employing these strategies can be configured independently. As shown in the simulations, this is an interesting feature that could be, for instance, employed for the integration of different dynamic generation or storage systems, such as batteries or supercapacitors.

A statistical approach for hybrid energy storage system sizing based on capacity distributions in an autonomous PV/Wind power generation system

Hybrid Energy Storage System (HESS) integration with autonomous PV/Wind hybrid power system becomes, currently, an interesting option for the improvement of the storage units' reliability and the life cycle assessment. In this paper, a new method for optimally sizing of HESS based on a statistical approach is proposed. This approach aims to exploit the capacity distribution of hybrid supercapacitor-battery system in an autonomous PV/Wind power generation system. This hybridization, of both slow and fast dynamics, aims to eliminate the power peaks caused by the load consumption. For the power distribution for all coordinated components of the storage system, a frequency management control and a hysteresis strategy are used in order to accomplish two goals: firstly, to delimit this exchanged power for not exceeding the maximum value and, secondly, to keep the States Of Charge (SOC) of the batteries-supercapacitors in a suitable range. Moreover, statistical analysis of several cumulative levels was performed to examine their contribution on the HESS optimal sizing. The obtained results prove that the integration of supercapacitor takes advantage of the complementary characteristics of the batteries, improves the exchanged power flow, extends the battery life cycle and affects on storage system sizing through accommodate the fast power fluctuations.

Techno-Economic Evaluation of Regulation Service from SEVs in Smart MG System

A techno-economic evaluation of regulation service of microgrid system comprising renewable energy resources and electric vehicles has been done in this paper. EV operational strategy for MG regulation is developed by incorporating a vehicle controller which enables vehicle to grid or grid to vehicle mode operation, while plugged into the power distribution circuit. The functionality of grid integration of electric vehicle with vehicle to grid or grid to vehicle operation makes it a smart electric vehicle, suitable for operation in smart microgrid environment. The techno-economic analysis is based on simulation results obtained from a microgrid test system operated with varying power generation and frequency regulation being provided by two different microgrid resources i.e., conventional battery storage system and proposed smart electric vehicles. The cost for providing frequency regulation using battery storage system and grid integration of vehicle is calculated and compared to find microgrid optimal operation option. The comparison of two costs reveals that smart electric vehicles have considerable economic potential for microgrid regulation service and hence provide better utilization of resources for optimal operation.

Energy model optimization for thermal energy storage system integration in data centres

In the last years the total energy consumption of data centre industry has experienced a rapid increase due to the vast growth in internet usage. This phenomenon has aroused the interest for both, data centre industry and researchers in energy consumption and carbon footprint mitigation. Data centres operational expenses are also a key parameter for the productivity and competitiveness of the industry. In the present work, the implementation and optimization of thermal energy storage (TES) into a real data centre is presented. To the knowledge of the authors this is the first time that a methodology based on TraNsient System Simulation (TRNSYS), GenOpt and the application of Hooke and Jeeves optimization algorithm is used to study the implementation of TES, in particular water storage tanks, in data centres. A sensitivity analysis on the TES system cost is performed in function of the available literature information. The results show that the operating temperature of the chillers should be as lower as the system allows and therefore this open the possibility to study ice storage system. Regarding the economic analysis, the data centre electricity expenses can be reduced annually up to 3%. The uncertainty of the electricity price in the future is a major issue and it is also discussed.

Experimental evaluation of a flexible I/O architecture for accelerating workflow engines in ultrascale environments

Abstract The increasing volume of scientific data and the limited scalability and performance of storage systems are currently presenting a significant limitation for the productivity of the scientific workflows running on both high-performance computing (HPC) and cloud platforms. Clearly needed is better integration of storage systems and workflow engines to address this problem. This paper presents and evaluates a novel solution that leverages codesign principles for integrating Hercules—an in-memory data store—with a workflow management system. We consider four main aspects: workflow representation, task scheduling, task placement, and task termination. The experimental evaluation on both cloud and HPC systems demonstrates significant performance and scalability improvements over existing state-of-the-art approaches.

Management Strategy for Market Participation of Photovoltaic Power Plants Including Storage Systems

Energy storage systems (ESS) integration with large-scale photovoltaic (PV) power plants, named intelligent PV (IPV) power plant, could contribute to improving the viability of these plants and to provide ancillary services to the main grid. The number and extension of the provided services depend not only on the size of the ESS, but also on the manner in which this storage system is managed. In this paper, the market participation based on different firming control strategies of an IPV power plant is proposed to optimize the economic exploitation based on the storage system management considering PV generation predictions. The most appropriate firming control strategy is selected to participate on the daily market, which is strengthened with an online model predictive control (MPC) to compensate the PV prediction errors participating in the intraday market. The real operation of the Iberian Peninsula market integration is also explained and analyzed. The development of this management strategy considers as a case study a real IPV plant located in Tudela (Navarre, Spain) and owned by Acciona Energia, which included a Lithium-ion based ESS from 2012 to 2013 in the framework of a European project. The results show that considering the MPC approach, an increase around 20% in the benefits is obtained by comparing with the daily market participation.

A Design of DBaaS-Based Collaboration System for Big Data Processing

With the recent growth in cloud computing, big data processing and collaboration between businesses are emerging as new paradigms in the IT industry. In an environment where a large amount of data is generated in real time, such as SNS, big data processing techniques are useful in extracting the valid data. MapReduce is a good example of such a programming model used in big data extraction. With the growing collaboration between companies, problems of duplication and heterogeneity among data due to the integration of old and new information storage systems have arisen. These problems arise because of the differences in existing databases across the various companies. However, these problems can be negated by implementing the MapReduce technique. This paper proposes a collaboration system based on Database as a Service, or DBaaS, to solve problems in data integration for collaboration between companies. The proposed system can reduce the overhead in data integration, while being applied to structured and unstructured data.

(Invited) Graphene Plane Electrode for Low Power 3D Resistive Random Access Memory

In this work, we introduce one of the world’s thinnest non-volatile memory stacked in a 3-dimensional vertical structure. We exploit the edge of an atomically thin graphene layer and form a metal oxide resistive memory using HfOx as the switching oxide. We found that such thin memory has potential for highly integrated storage system with memory density higher than the same memory structure made using thin metal layer. We also confirm that it is not possible to build such thin memory with conventional metal because the sheet resistance of metal dramatically increases as it is thinned down to less than 5 nm.

A Holistic Approach to the Integration of Battery Energy Storage Systems in Island Electric Grids With High Wind Penetration

This paper details an optimization tool for the planning and operation of battery energy storage systems (BESS) in island power systems with high wind penetration. The selection of the most suitable battery technology, its sizing and location is achieved through a comparative analysis of the operational and capital expenditure of the islanded system during the planning horizon with and without the deployment of the BESS solution. An operational algorithm is developed consisting on sequentially closer to time of delivery optimization stages in order to provide a robust quantification of the technical, environmental, and economic impacts of the battery system. The developed methodology is assessed and validated in a real-world case study of a Portuguese island with a high share of wind generation. Results show that BESS enhances the flexibility of the islanded power system thus ensuring a higher accommodation of wind energy with significant economic benefits.

Thermo-economic analysis of the energy storage role in a real polygenerative district

This paper presents a thermo-economic analysis based on data from a real Smart polygeneration microgrid (SPM), designed to satisfy energy demands of the university campus of Savona (Italy). The plant is made up of different cogenerative generators (micro gas turbines and an internal combustion engine), renewable generators and two auxiliary boilers (one of them is off during the most of the time): the generators are “distributed” around the campus and coupled to electrical and thermal storages. Since several cogenerative units are included in the grid, the integration of the different storage systems is relevant in order to determine the best management strategy, following both thermal and electrical requests and taking into proper account the strong difference between the two energy demand profiles.The thermo-economic analysis is performed exploiting the software W-ECoMP, developed by the authors’ research group, in order to find the best operational strategy, considering the importance of an appropriate storage system to manage the polygenerative energy district; attention is paid to the integration and combination of three different kinds of storage (hot and cold water tanks and electrical battery). Different scenarios are presented, combining the storages and showing their impact in terms of money savings and reduction of electrical energy purchasing from the National grid. Both the grid connected mode and island mode of operation of the SPM are considered.The analysis is performed considering the time dependent nature of the energy demands throughout the whole year and implementing the experimental off-design curves of the real devices installed in the grid.

Potential of Redox Flow Batteries and Hydrogen as Integrated Storage for Decentralized Energy Systems

The requirement for low-cost access to energy storage technologies is increasing with the continued growth of renewable energy. The growth of the hydrogen economy is also expected to emerge to improve energy security and meet the growing pressures of environmental requirements. Hydrogen and redox flow batteries (RFB) have promising energy storage characteristics that can allow increased penetration of renewable energy and reduction in grid energy. The strong synergy between natural gas and hydrogen anticipates that new efficient methods of hydrogen production such as microwave plasma processing of natural gas might have a leading role. Additionally, the improvements in the carbon allotropes properties and their cost are expected to influence large-scale energy storage system costs. A technical and economic comparison of vanadium and all-iron RFB with hydrogen will be explored on an individual and integrated basis. The findings show hydrogen’s capability for bulk energy storage and highlights the benefits of integrated storage. This proves that integration of various storage systems can play an important role for the future development of the decentralized renewable energy systems.

Kerf loss silicon as a cost-effective, high-efficiency, and convenient energy carrier: additive-mediated rapid hydrogen production and integrated systems for electricity generation and hydrogen storage

Kerf loss silicon was used for additive-mediated rapid hydrogen production with a rate of 4.72 × 10−3g(H2) per s per g(Si) and a yield of 92%. A silicon-based integrated system for electricity generation and hydrogen storage was demonstrated.

Sistemas Integrados de Potencia en Buques Offshore: Control, tendencias y retos

The offshore vessels require a high precision speed control and dynamic positioning. Adverse weather conditions and/or rough waves give rise to high disturbances that must be rejected by the control system to keep the vessel position in the area or station where the vessel operation is being executed. Other requirements related to the safety, reliability and robustness must be obviously ensured. Since more than a decade the power system of this kind of vessels is based on a diesel-electric power plant where the propellers and thruster units are controlled by electrical drives. In this power system the required electrical energy/power is generated through diesel gensets, and distributed to the propulsion drives (and to the rest of vessel utility loads) through a power grid. In this work the most commonly used integrated power system architecture is first introduced thus identifying the control functions and their interdependencies. Some trends and new power system topologies to improve the energy efficiency are then also presented and described. The emergence of new solutions based on DC grids allows the diesel gensets to operate at variable speed and makes the integration of the energy storage systems or even some renewable energy systems easier. However, they present some technical and design challenges in order to ensure a stable and robust solution by design. One of them is related to the stability analysis of the DC grid when multiple nonlinear constant power loads (negative impedance) are connected and thus interacting on the same DC bus.

Research on the application of hybrid cloud desktop design method

Through the study of hybrid cloud desktop , proposed technical solutions based on hybrid cloud desktop, On the basis of this, a detailed research and design of the hybrid cloud desktop is carried out, including the architecture of a hybrid cloud desktop solution and the PNS Desktop Virtualization (IDV), PNS Server Virtualization (VDI) and PNS QuickCloud cloud storage system integration, to achieve the centralized management and control of the client operating system, convenient and fast to meet the individual needs, centralized data management, the realization of the hybrid cloud desktop computer management, and improve the management level of the computer, improves the efficiency,it is virtual desktop changes to traditional PC desktop.

Techno-economic heat transfer optimization of large scale latent heat energy storage systems in solar thermal power plants

Concentrated solar power plants with integrated storage systems are key technologies for sustainable energy supply systems and reduced anthropogenic CO2-emissions. Developing technologies include direct steam generation in parabolic trough systems, which offer benefits due to higher steam temperatures and, thus, higher electrical efficiencies. However, no large scale energy storage technology is available yet. A promising option is a combined system consisting of a state-of-the art sensible molten salt storage system and a high temperature latent heat thermal energy storage system (LHTESS). This paper discusses the systematic development and optimization of heat transfer structures in LHTESS from a technological and economic point of view. Two evaluation parameters are developed in order to minimize the specific investment costs. First, the specific product costs determine the optimum equipment of the latent heat storage module, i.e. the finned tube. The second parameter reflects the interacting behavior of the LHTESS and the steam turbine during discharge. This behavior is described with a simplified power block model that couples both components.

Integrated hydrogen production and power generation from microalgae

Abstract An integrated system for hydrogen production, storage, and power generation from microalgae using enhanced process integration technology is proposed. Enhanced process integration has two core technologies: exergy recovery and process integration. Exergy recovery is performed through exergy elevation and heat coupling to minimize exergy destruction. The unrecoverable energy/heat in a single process is recovered and used in other processes through process integration. The proposed integrated system includes supercritical water gasification, hydrogen separation, hydrogenation, and a combined cycle. The microalga Chlorella vulgaris is used for modeling and evaluation. Microalgae are converted to syngas, then separated to produce highly pure hydrogen. To store the produced hydrogen, the toluene–methylcyclohexane cycle as a liquid organic hydrogen carrier is adopted. The remaining gas is used as fuel for combustion in the combined cycle to generate electricity. The effects of the fluidization velocity and gasification pressure on energy efficiency are evaluated. From process modeling and calculation, high total energy efficiency (higher than 60%), including electricity generation efficiency of about 40%, can be realized.

A Review of Architectures and Concepts for Intelligence in Future Electric Energy Systems

Renewable energy sources are one key enabler to decrease greenhouse gas emissions and to cope with the anthropogenic climate change. Their intermittent behavior and limited storage capabilities present a new challenge to power system operators to maintain power quality and reliability. Additional technical complexity arises from the large number of small distributed generation units and their allocation within the power system. Market liberalization and changing regulatory framework lead to additional organizational complexity. As a result, the design and operation of the future electric energy system have to be redefined. Sophisticated information and communication architectures, automation concepts, and control approaches are necessary in order to manage the higher complexity of so-called smart grids. This paper provides an overview of the state of the art and recent developments enabling higher intelligence in future smart grids. The integration of renewable sources and storage systems into the power grids is analyzed. Energy management and demand response methods and important automation paradigms and domain standards are also reviewed.