San Diego Utility bets on big batteries for peaking and renewable electricity

SDG&E Unveils World’s Largest Li-Ion Storage Battery

California utility San Diego Gas & Electric (SDG&E) on February 24 officially put into service what is currently the largest lithium-ion storage battery in the world, wrapping up a fast-track procurement process that began less than a year ago.



The 30-MW, 120-MWh Advancion 4 system is supplied by AES Energy Storage and located in Escondido about half an hour north of San Diego is part of an expedited response by the state and the California Public Utilities Commission (CPUC) to the loss of the Aliso Canyon natural gas storage facility north of Los Angeles last year. The sudden loss of that storage capacity put major constraints on the area’s gas-fired generation and meant that peaker facilities faced the risk of not having gas to run when they were needed.



AES to install largest battery-based energy storage project in US for SDG&E | Energy Storage News
AES will deploy its Advancion 4 storage systems at two SDG&E substations in San Diego County, California, with 30MW in Escondido and 7.5MW in El Cajon.

AES will deploy its Advancion 4 storage systems [Advancion® Energy Storage - AES | Energy Storage] at two SDG&E substations in San Diego County, California, with 30MW in Escondido and 7.5MW in El Cajon. They will help the utility improve regional reliability and integrate more renewable energy. The Advancion arrays will be able to provide 37.5 MW of power for four continuous hours and serve as a 75 MW of flexible resource to the grid.

The systems will include batteries by Samsung SDI and power conversion systems by Parker Hannifin. The power conversion technology meets IEEE 519 and IEEE 1547 standards and is designed to UL1741 and UL508C as applicable. Certified PCS suppliers are pre-qualified for Advancion arrays at AES’ Battery Integration Center. Some of the latest changes in the Advancion 4 architecture are also aimed at reducing balance-of-systems costs -- something that GTM Research has predicted will be an important part of overall grid battery system cost reductions over the coming years.

Battery vendor LG Chem and inverter maker Parker Hannifin are AES’ first two announced Advancion partners. That fact, plus a December announcement of a massive supply agreement with the South Korean lithium-ion battery maker, led many in the industry to presume that the Netherlands project was using LG Chem batteries. But in fact, the Netherlands project is using Samsung, AES Energy Storage President John Zahurancik said in an interview earlier this month.

In the past month, AES has also brought in new partners Mitsubishi and Eaton to expand its Advancion business to new markets, in Asia and Oceania and in Europe, Africa and the Middle East, respectively. It’s all part of a broader push to lower the cost and complexity of energy storage deployments and bring more flexibility to how they’re put to play, he said.

AES | Energy Storage | Features & Specs

One of the changes of Advancion 4 “allows us to have a very compact footprint, so this is four to five times more compact than what we were building five or six years ago,” he said. “That ends up translating into cost -- less conduit, less racking, less concrete, less everything.”
In terms of flexibility, AES has “gone to a smaller, individual unit -- what we’re calling a node -- partnered up with a bunch of its brothers to form an array,” he said. “Each of these nodes can operate independently. Its operating characteristics or lifespan can be maintained independently.”

SDG&E bets on big batteries for Clean Power
A collection of 24 large, stationary containers dot an industrial park at the San Diego Gas & Electric operations center in Escondido. The site represents the world’s largest lithium-ion battery energy storage center, completed in a matter of months and designed to improve energy reliability for the region. The 30-megawatt plant consists of 400,00 batteries, similar to those used in electric cars. The batteries were installed in almost 20,000 modules that sit in massive containers with the capability of serving about 20,000 SDG&E customers for four hours.

“It’s a way for us to maximize the use of clean, renewable energy generation,” said Josh Gerber, SDG&E’s manager of advanced technology integration. “All of that is good for the system, it helps us avoid turning on other plants that might be needed to meet the region’s demands.”

Related/Background

• Unleashing the Power of Energy Storage | Energy Storage Association
•  World's Largest Storage Battery Will Power Los Angeles - Scientific American
•  Energy storage coming to a power grid near you - CNET
•  Why battery storage is 'just about ready to take off' | Utility Dive
• Why Energy Storage is About to Get Big – and Cheap | Ramez Naam 
•  Energy Storage | SEPA
•  SDG&E unveils lithium battery storage facility - CBS News 8 - San Diego, CA News Station - KFMB Channel 8
•  SDG&E Seeks Energy Storage, Renewable and Other Clean Energy Resources - California Business News
• Samsung’s Recall: The Problem With Lithium-Ion Batteries - The New York Times

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  doi: 10.1109/TPS.2014.2370053
  Abstract: There is considerable need for a mobile, reliable, efficient, and compact prime power supply for a host of applications, including directed energy and electrical grid backup among others. Electrochemical energy storage devices, which possess either high-power density or high-energy density, have been developed recently and are very applicable for use in these applications. The need for both high energy and high power, however, makes the design and implementation of such a prime power supply a nontrivial task. While lithium-ion batteries (LIBs) are available, which possess both high power and energy density, operation at high power reduces their cycle life, decreasing the reliability and increasing the cost of the system when replacement becomes necessary more frequently. One proposed method involves optimally combining high-energy batteries with high-power electric double layer capacitors (EDLCs) using actively controlled power electronics to regulate the current to and from each respective device. In such a scheme, energy can be slowly sourced to and from the batteries, while the capacitors are used to supply or accept the bulk of the current when the demand is high, especially during fast transients. This type of scheme should not only maximize the batteries' cycle life and ensure that both the energy and power required of the load(s) is always available, but will also increase the instantaneous power capabilities of the system, offering a well-rounded solution to sourcing steady and/or transient loads. When augmenting a fossil fuel generator with a hybrid energy storage module (HESM), the HESM has the ability to act as a high-energy reservoir that can harvest energy from the generator when the loads are in short periods of inactivity. This enables the generator to be continuously base loaded, thereby maintaining a high level of efficiency at all times, while theoretically maintaining the required power quality of the main ac bus. At the University of Texas at A- lington (UTA), an actively controlled, high-rate HESM has been constructed to evaluate its performance under the typical load condition presented by directed energy weapons. It has been assembled using LIBs, EDLCs, and commercial off-the-shelf power electronic converters. A discussion about the future of HESMs, the experimental setup at UTA, and the results obtained thus far will be presented here.
  keywords: {lithium;power convertors;power supply quality;secondary cells;supercapacitors;EDLCs;HESM;LIBs;ac bus;actively controlled hybrid energy storage module;actively controlled power electronics;battery life cycle;commercial off-the-shelf power electronic converters;compact prime power supply;directed energy weapons;electrical grid backup;electrochemical energy storage devices;fossil fuel generator;high-energy batteries;high-energy density;high-energy reservoir;high-power density;high-power electric double layer capacitors;high-rate directed energy;lithium-ion batteries;power quality;transient loads;Batteries;Capacitors;Generators;Inverters;Power supplies;Energy storage;lithium batteries;power electronics;power electronics.;supercapacitors},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6966789&isnumber=7102802
  
  A. Dunbar, F. Tagliaferri, I. M. Viola and G. P. Harrison, "The impact of electricity price forecast accuracy on the optimality of storage revenue," 3rd Renewable Power Generation Conference (RPG 2014), Naples, 2014, pp. 1-6.
  doi: 10.1049/cp.2014.0902
  Abstract: Grid connected electrical energy storage could enable large numbers of intermittent renewable generators to be deployed in the UK. Many studies investigate the revenue which could be achieved through arbitrage assuming perfect foresight of electricity prices. In practice, storage operators will not have perfect foresight and will have to devise operational strategies using price forecasts. This paper investigates the impact of forecast accuracy on the optimality of storage revenue. The optimal revenue available is determined using linear programming and historic electricity prices. The results are compared to those found using dynamic programming and electricity price forecasts with increasing percentage error. A small scale lithium ion battery and a large pumped hydro energy storage (PHES) device are compared. The results show that revenue reduces at an increasing rate with increasing forecast error. The PHES device is more sensitive to forecast accuracy than the lithium ion battery. For both technologies, with a maximum error of 30%, 80% of the optimal revenue can be achieved. With increased capacity and significantly increased power rating, the lithium ion battery becomes more sensitive to price forecast accuracy.
  keywords: {dynamic programming;linear programming;pricing;pumped-storage power stations;secondary cells;PHES device;dynamic programming;electricity price forecast accuracy;grid connected electrical energy storage;historic electricity prices;linear programming;pumped hydro energy storage;small scale lithium ion battery;storage revenue optimality;Dynamic programming;Electricity Storage;Forecast Accuracy;Price Arbitrage},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6993295&isnumber=6941339
  
  H. Weiss, "Power electronics as key factor in generation, transmission, and usage of electric energy," 2014 ELEKTRO, Rajecke Teplice, Slovakia, 2014, pp. 20-20.
  doi: 10.1109/ELEKTRO.2014.6847862
  Abstract: Electrical energy exhibits highest flexibility in usage and controllability. However, electrical energy also raises high cost in generation and storage and is not sustainable in most cases for generation (burning coal or oil, or nuclear reactors). Advanced and sustainable generation employs power electronics in various circuits and power ranges. By today, large water power pump turbines with synchronous machines are speed controlled by converters even over 100 MW. State of the art is the modular multilevel conversion system with IGCTs or IGBTs along with antiparallel diodes. Wind power plants use permanent magnet synchronous machines again with full power converters. Photovoltaics become the field for application of SiC devices. HVDC transmission in classic style finds line commutated thyristors along with filter equipment that again uses power electronics for harmonics reduction. At less than about 1 GW we again see modular multilevel conversion circuits. Electric energy from Lithium-ion batteries as direct power source for individual mobility is used in zero-emission vehicles which rely on simple to complicated power electronics for realization of variable speed drives. Future applications can introduce Lithium-ion batteries not suited any more for mobile usage as local energy storage elements buffering power from renewable energy sources. Such applications require power electronics for energy conversion and easy control establishing an actually smart grid.
  keywords: {generation of electric energy;transmission of electric energy},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6847862&isnumber=6847850
  
  C. Guenther, J. K. Barillas, S. Stumpp and M. A. Danzer, "A dynamic battery model for simulation of battery-to-grid applications," 2012 3rd IEEE PES Innovative Smart Grid Technologies Europe (ISGT Europe), Berlin, 2012, pp. 1-7.
  doi: 10.1109/ISGTEurope.2012.6465855
  Abstract: The number of fluctuating energy sources in the power grid increases continuously. Simultaneously the importance of electrical energy storage increases. Batteries are one promising possibility for short-term storage. In this work a mathematical impedance model of a Lithium-ion battery with high dynamics for simulation of loads due to driving cycles and battery-to-grid applications as well as parameterization and validation of the model are presented. The model approach is based on an equivalent circuit. Parameterization of the model is done at many different operating points to assess the dependencies of the parameters on different battery states and model inputs. Both for high dynamic impacts and static periods simulation of terminal voltage shows good results in the considered operational range. The model is real time capable and suitable for robust control. Hence a useful tool for battery-to-grid and electric mobility applications is introduced.
  keywords: {equivalent circuits;lithium;mathematical analysis;robust control;secondary cells;smart power grids;Li;battery-to-grid simulation applications;driving cycles;dynamic battery model;electric mobility applications;electrical energy storage;equivalent circuit;fluctuating energy sources;lithium-ion battery;mathematical impedance model;power grid;robust control;short-term storage;terminal voltage static period simulation;Batteries;Battery charge measurement;Integrated circuit modeling;Mathematical model;System-on-a-chip;Temperature measurement;Voltage measurement;Battery model;LiFePO4;Lithium-ion;battery-to-grid;mathematical model;smart grid applications},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6465855&isnumber=6465601
  
  J. D. Dogger, B. Roossien and F. D. J. Nieuwenhout, "Characterization of Li-Ion Batteries for Intelligent Management of Distributed Grid-Connected Storage," in IEEE Transactions on Energy Conversion, vol. 26, no. 1, pp. 256-263, March 2011.
  doi: 10.1109/TEC.2009.2032579
  Abstract: Grid-connected electrical storage has a high potential to support the transition toward a reliable decentralized and renewable energy supply. It is expected that lithium-ion batteries will play a major role in this transition, because of their high energy density and of the potential capacity that is offered by plug-in (hybrid) electric vehicles. The use of lithium-ion batteries in grid support may result in additional degradation. Intelligent control of these batteries can assure that the additional degradation rate is minimized and their utilization is cost-effective. It is, therefore, imperative that the intelligent control has an excellent understanding of the aging behavior of the battery, therefore, it can maximize the benefits for the battery owner. Based on this logic, cycle life experiments were performed on lithium polymer cells in which the cell life dependence on the depth of discharge was investigated. Other cell characteristics that were studied include the equivalent series resistance and the efficiency.
  keywords: {battery management systems;battery powered vehicles;battery storage plants;distributed power generation;hybrid electric vehicles;intelligent control;lithium;secondary cells;smart power grids;Li;Li-ion batteries;cell life dependence;cycle life experiments;distributed grid-connected storage intelligent management;equivalent series resistance;intelligent control;lithium polymer cells;plug-in hybrid electric vehicles;renewable energy supply;smart grids;Cycle life;depth of discharge (DOD);equivalent series resistance (ESR);lithium polymer (LiPo)},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5677460&isnumber=5714224
  
  A. Ahsan, Q. Zhao, A. M. Khambadkone and M. H. Chia, "Dynamic battery operational cost modeling for energy dispatch," 2016 IEEE Energy Conversion Congress and Exposition (ECCE), Milwaukee, WI, USA, 2016, pp. 1-5.
  doi: 10.1109/ECCE.2016.7855055
  Abstract: Battery Energy Storage Systems (BESS) have gained extensive application in both grid and microgrid applications. One major type of BESS are electrochemical batteries such as Lead-Acid and Lithium-Ion batteries which have limited number of lifecycles. The common way of considering their operation cost is using a constant value such as LCOE (levelized cost of energy). However, as shown herein, given the same amount of energy output, the battery lifecycle degradation, and thus the degradation cost, can vary at different operation conditions (voltage, current, power, state of charge (SOC)) by up to 6 times. Herein a model for the dynamic battery operation cost as a function of its dispatch power and SOC is developed. The model also considers the dependency of battery voltage on its current and SOC, which equivalently takes into account the dependency of its conversion efficiency on its power and SOC. Preliminary simulations demonstrate that using the proposed model, instead of the LCOE, for Microgrid operation optimization microgrid operation cost is lower by up to 12%.
  keywords: {Batteries;Degradation;Discharges (electric);Load modeling;Microgrids;State of charge;US Department of Defense},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7855055&isnumber=7854636
  
  S. S. Saha, S. Janko, N. G. Johnson, R. Podmore, A. Riaud and R. Larsen, "A universal charge controller for integrating distributed energy resources," 2016 IEEE Global Humanitarian Technology Conference (GHTC), Seattle, WA, USA, 2016, pp. 459-465.
  doi: 10.1109/GHTC.2016.7857320
  Abstract: Centralized electric grids provide power to much of the world's population, yet cost and technical constraints prevent grid extension to 1.2 billion people living without power today. Off-grid and micro-grid power systems are solutions to electrifying remote areas of developing countries. Generally, these systems include a mix of renewables, storage, conventional generation, and demand response or metering, with a wide variety of controllers needed to address the many possible power system configurations and component specifications. Existing low-cost technologies have limited interoperability and flexibility to span the problem space. This paper seeks to address this need and describes the motivation, requirements, specifications, prototyping, and early testing of a Universal Charge Controller (UCC) that integrates with various sources, loads, and storage. The UCC meets load requirements for a household or other small building up to 500W peak load capacity. Power source connections include solar photovoltaics (18–24VDC), battery storage (12–24VDC), an AC micro-grid (110/220VAC), or a DC micro-grid (50–70VDC). This flexibility, combined with intelligent controls, permits the UCC to serve as the keystone in connecting various energy architectures as a community develops over time. The UCC can charge a 12V or 24V Lead Acid or Lithium-Ion battery from one or more sources (current controlled or voltage controlled). Storage charging efficiency is improved with Maximum Power Point Tracking (MPPT) during the conversion of solar power. The accuracy of the design parameters was analyzed by testing different use cases on a commercial development board with results used to refine specifications and schematics of the UCC prototype. Technical specifications and design documentation are in development through an open source partnership with IEEE Smart Village to promote widespread adoption.
  keywords: {Batteries;Integrated circuits;Maximum power point trackers;Microgrids;Solar panels;Testing;Smart Village;UCC;charge controller;microgrid;off-grid;solar},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7857320&isnumber=7857239
  
  K. Li and K. J. Tseng, "An electrical model capable of estimating the state of energy for lithium-ion batteries used in energy storage systems," 2016 IEEE 2nd Annual Southern Power Electronics Conference (SPEC), Auckland, New Zealand, 2016, pp. 1-8.
  doi: 10.1109/SPEC.2016.7846167
  Abstract: The state of energy (SOE) of Li-ion batteries is a key indicator for the energy management and optimization of energy storage systems (ESSs) in smart grids and electric vehicles (EVs). In order to improve the SOE estimation accuracy, an electrical Li-ion battery model is presented in this study against the dynamic loads and the rate energy effects of the battery. Firstly, in order to take into thorough consideration of the influencing factors in the SOE estimation process, a look-up table is merged with a 2^nd order RC battery model for accurately predicting the battery voltage characteristics and capturing the nonlinear rate energy effects to realize the high-fidelity battery SOE and runtime prediction; Secondly, a new method to separate the fast and slow dynamics of the 2^nd order RC battery model is developed and presented with a high-performance accuracy; Thirdly, commercial Li-ion batteries are tested at dynamic loads with various temperature to validate the effectiveness of the proposed model. The testing results show high accuracy and reliability of the proposed electrical battery model on the estimation of the battery SOE and the terminal voltage responses under dynamic loads.
  keywords: {Batteries;Estimation;Integrated circuit modeling;Load modeling;Power system dynamics;Predictive models;Vehicle dynamics;Li-ion battery;battery discharging;electrical model;state of energy;transient parameters},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7846167&isnumber=7845525
  
  S. Steinhorst, "Design and verification methodologies for Smart Battery Cells," 2016 International Symposium on Integrated Circuits (ISIC), Singapore, 2016, pp. 1-4.
  doi: 10.1109/ISICIR.2016.7829706
  Abstract: Lithium-Ion (Li-Ion) battery packs are continuously gaining in importance in many energy storage applications such as electric vehicles and smart energy grids. Such battery packs require advanced Battery Management Systems (BMSs), which are contributions from the embedded systems and integrated circuits domain. The BMS monitors and controls the battery cells in a pack and ensures the functionality, efficiency, safety and reliability of the pack. Conventional BMS designs employ a centralized controller architecture for the whole battery pack. Recently, Smart Battery Cells have been proposed which enable a complete decentralization of the BMS. In Smart Battery Cells, each cell is equipped with a Cell Management Unit (CMU) which individually manages the cell it is attached to. By communication with other Smart Battery Cells, the pack-level functionality of the BMS is provided in a distributed fashion. While this architecture provides many benefits such as scalability, minimal integration effort and increased functional safety, existing design and verification methodologies can neither be applied on hardware nor on software level. Consequently, this contribution will discuss how such methodologies for Smart Battery Cells could be developed and points out which further research contributions are needed. For this purpose, we address modeling and simulation of cyberphysical aspects on all abstraction levels and illustrate how verification approaches can be introduced to this new field of application.
  keywords: {battery management systems;lithium compounds;secondary cells;Li-Ion battery pack reliability;advanced BMS;advanced battery management system;cell management unit;centralized controller architecture;energy storage applications;lithium-ion battery pack;smart battery cell design methodology;smart battery cell verification methodology;Algorithm design and analysis;Analytical models;Batteries;Computer architecture;Integrated circuit modeling;Security},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7829706&isnumber=7829673
  
  G. Barzilai, L. Marcus and G. Weiss, "Energy storage systems — grid connection using synchronverters," 2016 IEEE International Conference on the Science of Electrical Engineering (ICSEE), Eilat, 2016, pp. 1-5.
  doi: 10.1109/ICSEE.2016.7806095
  Abstract: We investigate the design of future energy storage systems by exploring one particular solution, in simulations. We use Lithium-ion batteries for storage, a dual active bridge (DAB) for DC to DC conversion and a synchronverter to transfer energy from the DC bus to the utility grid. We show how some recent improvements to the synchronverter algorithm can be combined with a battery management algorithm that will charge or discharge the batteries to achieve a maximal profit for the operator of the storage station, while at the same time contributing to the stability of the grid by providing frequency droop, voltage droop inertia and fault ride-through. We discuss different open loop and closed loop control algorithms for the DAB as well as for the overall system that will further increase its efficiency. We simulate the use of two DABs, one for the positive DC voltage and one for the negative one, with a 5KW three-level synchronverter working on the 230V grid.
  keywords: {DC-DC power convertors;battery management systems;bridge circuits;closed loop systems;energy management systems;energy storage;open loop systems;power grids;power system faults;power system stability;secondary cells;DAB;DC to DC conversion;battery charging;battery discharge;battery management algorithm;closed loop control algorithm;dual active bridge;energy storage systems;energy transfer;fault ride-through;frequency droop;grid connection;grid stability;lithium-ion batteries;open loop control algorithm;storage station;synchronverter algorithm;three-level synchronverter;utility grid;voltage droop inertia;Batteries;Bridge circuits;Control systems;Electrical engineering;Inverters;Power system stability;Synchronverter;droop control;dual active bridge;energy storage system;model predictive control},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7806095&isnumber=7806027
  
  T. Vogt, R. Pahl, N. Fröhleke and J. Böcker, "Determination of storage loss characteristics with reasonable measurement and calculation effort," 2016 18th European Conference on Power Electronics and Applications (EPE'16 ECCE Europe), Karlsruhe, 2016, pp. 1-9.
  doi: 10.1109/EPE.2016.7695689
  Abstract: This paper presents a method how to simply determine the losses of an energy storage depending on state of charge and actual power. The proposed method only requires the measurement of electrical quantities to determine the characteristic map and therefore can be implemented without need to modify of an existing electrical storage system. Exemplary results are shown of lithium-ion and lead-acid battery packs. The losses of the used lead-acid battery pack shows a clear dependency on the state of charge, mainly a quadratic dependency on the terminal power and a difference between charge and discharge. The losses of the used lithium-ion battery packs shows in principle a similar result but with a much less significant dependency on the state of charge. The characteristic map of losses is useful to optimize the storage operation regarding minimal losses whenever a degree of freedom of the choice of storage power exists, e.g. in an energy management system of a microgrid for cost savings in the grid-coupled operation and longer back-up time in the island operation.
  keywords: {energy management systems;lead acid batteries;electrical storage system;energy management system;grid-coupled operation;lead-acid battery;lithium-ion battery;microgrid;Batteries;Battery charge measurement;Discharges (electric);Lead;Loss measurement;State of charge;Voltage measurement;Battery efficiency;Battery losses;Electrical energy storage;Energy management;Industrial microgrid;Lead-acid battery;Lithium-ion battery;Open-circuit voltage},
  URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7695689&isnumber=7695111