Challenges of Electrical Energy Storage

1. Challenges of Electrical Energy Storage Daniel R. Borneo Sandia National Laboratories Energy Infrastructure and Distributed Energy Systems drborne@sandia.gov 505-284-9880 June 16, 2010 Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2009-2801P

2. Overview • Challenges of Electrical Grid Energy Storage • Technology • Costs • Regulatory • Market / Deployment • Next Phase of Energy Storage • New technologies • Summary

3. Technology Challenges

4. Sodium Sulfur Flow Batteries Lithium ion Lead Acid Flywheels Super Capacitors Super Conductors Pumped Hydro CAES Technology

5. Technology - Applications POWER ENERGY Applications Applications LOAD GRID seconds minutes hours 5

6. Technology – Power Electronics • Power Electronics make up 25-60% of system cost. • Power Electronics presently do not have the desired reliability • Power conversion from storage to grid adds size, complexity and cost. Emitter Turn-off Thyristor -

7. Technology - Reliability • Cycle life • Limited systems in operation • Cycle life unknown over 7-10+ year time frame • Annual Cost • Replacement Costs • Operational costs

8. Technology - Capabilities • Need storage systems that can serve multiple applications • Need technology that has Energy and Power features • Laws of Physics + Laws of Chemistry = Murphy’s Law

9. Grid Independent ZBB PECC w/ PV& Storage Technology – PV power Example Courtesy of ZBB Energy - www.zbbenergy.com

10. Cycle life

11. Cost Challenges

12. Cost - Challenges • Present estimated costs have poor ROI • Hard to get well defined budgeting costs • Capital • Operational • Hidden costs • How to recover costs • Who takes the risks • Who reaps the various and varying benefits • Example?

13. Capital Cost for Various Technologies

14. Capital Cost per Cycle

15. Regulatory Challenges

16. Regulatory – Storage Policy Regulatory Uncertainty Numerous forums working issues FERC, NERC, State, Industry Advocates Investors Not all Energy Storage Technologies are alike New Storage products may need new rules Tariff Definitions Lacking Diverse Applicability Characteristics of energy storage Generator or consumer Some information on this sheet credited to SCE, Energy Storage Strategic Planning Project Presentation, May 25, 2010. Presenters: Alex Morris, Janos Kakuk

17. Regulatory - Owner/Operator/User Generation/Transmission/Distribution/User Is it generation, transmission, distribution or end user asset Who owns, operates, maintains Who’s taking the risk…Who’s reaping the benefits? Cost recovery Who has Jurisdiction of storage system installation and operation Approval Operation Rate case, Tariffs Bi-directional Flowdoes not fit into conventional

18. Next Phase of Energy StorageWhere do We Need to Go?

19. Some Goals Being Discussed Cell and Component Metrics Double energy storage density of electrochemical device by 2020 Some Common Energy Densities (From ESA) Li-ion = 300 kWh/m^3 LA ~ 30-60+ kWh/m^3 System Metrics (From ARPA-e GRIDS Solicitation) Technical Requirements < $100/kWh(Streeeeeeeetch goal) Minimum 60 min operation 0-100% in <10 minutes Technical Targets Minimum 5000 cycle life >80 % RT eff, < 5% internal losses in 24hr ≥ 20kw for prototypes, Scalable to 1-10MW + 10 year life We Need a revolution not an evolution! Note: A good source for current technology specifications can be found at http://www.electricitystorage.org/ESA/home/ 19

20. New Technologies Being Investigated by DOE’s National Laboratories

21. SNL’s New Redox Couples for Flow Batteries • Materials research and development for: • Higher energy density because materials acts as both the electrolyte and storage medium • Low cost, Safety, Environmentally benign, Cost effective scale-up options • Year 1: • extend concept to multivalent cations (beyond copper, iron, and zinc) • Year 2: • evaluate anion effect(s) • develop structure-activity relationships • Year 3: • complete laboratory prototype 21

22. SNL’s Full Air Breathing Battery Concept Concept is to use O2 and N2 as the electrodes in a battery Novel because N2 is considered inert SNL routinely reacts N2 electrochemically Challenging but appears feasible Enormous potential impact on stationary and mobile energy storage in both density and economic value Zn/Air has the highest energy density of aqueous battery chemistries because the weight of the cathode is not included in the calculation. The energy density would increase greatly beyond Zn/Air if the anode material were also derived from the air. • Year 1 - Establish electrochemical behavior in a novel electrolyte solution • Year 2 - Develop catalyzed anode & cathode structure • Year 3 - Complete cell integration & laboratory prototype 22

23. PNNL’s Low Cost, Long Life Li-Ion for Community Storage a 1.5~1.7 V e-1 e-1 b Li+ Li+ Li+ Li+ Li+ Li+ Li+ Cathode: Olivine LiFePO4 Anode: Li4Ti5O12 TiO2/Graphene Membrane (001) Charge • Take a different approach from that for vehicle applications, by emphasizing life and cost, instead of energy/power density • Develop unique Li-ion batteries made from cost-effective electrode materials that may allow for a long cycle life (>6,000 deep cycles) • Future work focuses on materials optimization, battery scale up and prototype system development Self-assembling Cathode: LiFePO4 Anode: self-assembled TiO2/graphene Electrolyte: 1M LiPF6 in EC/DMC 23

24. PNNL’s High Performance Redox Flow for Large Scale Storage • Redox flow batteries (RFB) allow for separate design of energy and power, capable of large scale energy storage for hours of discharge • However, present technologies are struggling to be technically and economically feasible at high power/energy ratings for broad market penetration • PNNL is developing new generation RFB that employ cost-effective, optimized electrolytes, membrane and electrodes to meet performance and cost-requirements for grid applications 24

25. Solar Energy Grid Integration Systems Energy Storage (SEGIS-ES) • Distribution Scale PV up to 100 kW • Residential • Small Commercial • Microgrids Develop Storage Technologies basedon current state-of-art for use with grid tied PV systems

26. Sandia’s Battery, Component & System Testing Utilities require impartial, third party testing before commitment to innovative storage devices and systems Cycle life, abuse, accelerated testing Development of testing protocols for various applications Startup, commissioning and functional acceptance testing of storage Systems Monitoring, data acquisition and analysis of demonstration projects ESMA Asymmetric SuperCap Maxwell Symmetric Supercap Okamura Labs SuperCap (ECaSS) Propylene Carbonate Enersys Cyclon VRLA Electro Energy Bipolar NiMH Saft Li-ion Tadiran Li-SOCl2 NessCap Symmetric SuperCap Acetonitrile NessCap Symmetric SuperCap Propylene Carbonate East Penn Solar Gel VRLA Battery Energy SunGel VRLA Battery Energy ALABC carbon VRLA East Penn Unigy II VRLA Beacon ZBB C&D MS Endure VRL Enersys PowerSafe V16) Exide Absolyte VRLA C&D Dynasty VRLA C&D 2XTHCP vented Lead-Acid NorthStar VRLA NorthStar ALABC carbon enhanced VRLA LiFeBatt Li-FePO4 Neosonic Li-FePO4 Polymer East Penn ALABC carbon enhanced large format VRLA Furukawa Ultrabattery VRLA C&D CPV Photovoltaic Lead-Acid Battery GS-Yuasa Silica/tubular VRLA East Penn Large Format ALABC PV Energy Smoothing Battery Maxwell

27. Conclusions Energy Storage makes “cents”…but it needs to make dollars. Need to get more systems in the field to drive down cost and increase system understanding and reliability Regulatory organizations need to develop rules of engagement Industry needs to develop means to reward the risk takers Holy Grail? Searching 2000 years for something which we we’re not sure what?

28. Reference Material • Benefit/Cost Framework for Evaluating Modular Energy Storage. SAND2008-0978. Addresses cost and performance for various types of energy storage. Also includes benefit/cost assessment examples for specific value propositions. • Solar Energy Grid Integration Systems –Energy Storage (SEGIS-ES). SAND2008-4247. Describes themes related to augmentation of the Solar Energy Grid Integration Systems (SEGIS) Program with energy storage for residential and small commercial systems (SEGIS-ES). (SEGIS is an industry-led effort to enhance the utility of distributed PV systems.) • Remote Area Power Supply (RAPS) Load and Resources Profiles. SAND2007-4268. Characterizes load and generation resource profiles that might be accommodated by Remote Area Power Supply (RAPS) systems used for rural electrification projects around the world. • Long vs. Short-Term Energy Storage: Sensitivity Analysis. SAND2007-4253. Characterizes long-duration and short-duration energy storage technologies, primarily on the basis of life-cycle cost, including sensitivity to various input assumptions, for three application categories. • Installation of the First Distributed Energy Storage System (DESS) at American Electric Power (AEP). SAND2007-3580. Describes direct and indirect benefits, strengths, and weaknesses of distributed energy storage systems (DESS) for use by AEP. DESS was investigated as “a way to transform its grid into a system that achieves optimal integration of both central and distributed energy assets.” • NAS® Battery Demonstration at American Electric Power. SAND2006-6740. Documents results of a demonstration of the sodium/sulfur battery (NAS) system by American Electric Power, including an economic analysis of a commercial NAS system at a typical site. Also included is a side-by-side demonstration of the capabilities of the NAS, a lead-acid battery system and flywheel-based energy storage for improving power quality. • Estimating Electricity Storage Power Rating and Discharge Duration for Utility Transmission and Distribution Deferral. SAND2005-7069. A framework for estimating power and energy requirements for storage used to defer a transmission or distribution upgrade.