1. Energy Storage Technologies : Benefits, Applications and Experiences
TERI-UNEP Workshop on Innovative and Sustainable Energy Technologies for Developing Countries: Opportunities and Challenges
(28th May – 30th May)
Energy Storage Technologies : Benefits, Applications and Experiences
May 29th, 2014
Sandhya Sundararagavan, Research Associate

2. Concerns / Issues Variability of RE Generation Supply-Demand Mismatch
Seasonal Variation in demand pattern
Wind capacity sits at 318 GW (GWEC , April 2014). Average growth rate for 18 years has been around %.
Source: MGVCL, SLDC, TERI (Analysis)

3. Energy Situation in South Asia
Energy security issues due to dependence on one fuel
Energy Access challenge to remote locations
Growing demands of energy
Increasing energy deficit
High T&D losses
Untapped renewable energy potential
Source: ADB South Asia Working Paper, Series 11; SAARC Regional Energy Trade Study, March 2010

4. Why is there a need for storage?
Balance supply-demand mismatch
Utilize storage for peak periods
Frequency and voltage support
Reliable power supply
Defer/reduce the need for new generation capacity and transmission upgrades
Distributed generation and Electric Vehicles
Emergency support

5. Types of Storage Technologies
Large scale Energy Storage
Pumped Hydro (PHS)
Compressed Air Energy Storage (CAES)
Thermal Energy Storage
Batteries
Lead-acid (Pb-acid), Lithium-ion (Li-ion)
Flow batteries : Vanadium redox and Zinc bromine (VRB, ZnBr)
Sodium Sulphur (NaS), Nickel Cadmium (NiCd)
Newer technologies
Flywheels
Super Magnetic Energy Storage (SMES)
Electrochemical Capacitors (EC)

6. Applications-Technologies Matrix
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA

7. Large Scale Energy Storage Systems
Compressed Air Energy Storage
Use off-peak electricity to compress air and store it in a reservoir
Above ground : 3-50 MW; Underground: up to 400 MW
Discharge Duration: 8-26 hours
Efficiency: 70%; life: 30 years
Geological/siting issue
Pumped Hydro (PHS)
Employs off-peak electricity to pump water from a reservoir up to another reservoir at a higher elevation
Can be sized up to 1 GW; Discharge duration 8-10 hours
Efficiency: 80-85%; Life: years
Siting/Permitting/Env. Impact issue
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA

8. Batteries – Mature and Commercial
Lead-Acid
Capacity range: 1 kW – 10 MW, Discharge duration: minutes to few hours
Most prevalent and cost effective storage system
Suitable for short duration application.
Life: yrs ; Efficiency: 75%
Disposal issue - toxic
Lithium-ion
Capacity range: 1 kW – 1 MW; Discharge duration: minutes to 4 hrs
Fast growing, commercial and mature
Leading technology platform for EV and PHEV
Short and medium duration applications
Life: 15 years; Efficiency: 90-95%
In August 2009, Hitachi completed a 10.4-MWh Lead-acid battery, built to stabilize a 15-MW wind facility at Goshogawara in northern Japan. A similar plant was installed in late 2010 at another wind-generation site at Yuasa.
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA

9. Batteries - Development
Sodium-Sulphur
Capacity range: MW; Discharge duration: seconds to 6 hours
Multiple, parallel standard units are used to create multi-megawatt systems
Suitable for grid support application
Life: 15 years; Efficiency: 75%
Requires operating temperature degree Celsius, which makes it hazardous and combustible
Flow Batteries
Capacity range: 50 kW – 1 MW; Discharge duration: 5-6 hours
Electrolytes stored in separate tanks which prevents deposition
Suitable for utility scale applications
Life: 20 years; Efficiency: 75-80%
Complexity of the design due to pumps and power control systems
The largest single installation of NaS is the 34-MW Rokkasho wind-stabilization project in Northern Japan that has been operational since August 1, At this time, about 316 MW of NaS installations have been deployed globally at 221 sites, representing 1896 MWh.
VRB: Currently 50-kW, 100-kW, 500-kW, 600-kW, and 1000-kW systems in operation. The largest in the U.S. is a 600-kW/3600-kWh system in a customer energy-management application. A 1-MW/5-MWh system is in operation in Japan.
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA

10. Other technologies Flywheels Thermal Energy Storage (TES)
Capacity range: 0.5 – 10 kWh
Suitable for shorter duration (milliseconds)
Life: 20 years, Efficiency: 70-80%
Safety issue with flywheel design and operating conditions
Thermal Energy Storage (TES)
Capacity Range: 10 – 50 kWh
Suitable for cooling in buildings and industrial processes
Life: >20 years, Efficiency: 75-90%
Thermal insulation, unique design configuration, and material properties
Okinawa Power has installed a 23-MW flywheel system for frequency regulation. Fuji Electric has demonstrated the use of flywheel technology to stabilize wind power generation. Spindle Grid Regulation, LLC, owns a 20-MW flywheel-based frequency-regulation facility in Stephentown, NY, that commenced operations in 2011 and sells frequency-regulation services to New York Independent System Operator (NYISO) under tariff rates.
TES
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA,

11. Pumped Hydro System in Taiwan
Success Stories
The Taiwan Power System contains ten PHS units: four 250 MW units located at the Ming-Hu hydro plant and six 267 MW units located at the Ming-Tan hydro plant
PHS units used for both time-shifting and operating reserve functions
Pumped Hydro System in Taiwan
Source: IEC White Paper, October 2012

12. Li-ion Battery Energy Storage System in West Virginia, USA
32MW/8MWh Li-ion battery storage solution
Supports 98 MW AES Laurel Mountain Wind Farm
Operational since 2011
Li-ion Battery Energy Storage System in West Virginia, USA
Source: Energy Storage Association (ESA)

13. NaS Battery System (Japan Wind Development Project)
51 MW wind farm (1500 kW X 34 units)
Supported by 34 MW Sodium-sulphur (NaS) system
Being operated by Japan Wind Development Corporation since three years
NaS Battery System (Japan Wind Development Project)
Source: IEC White Paper, October 2012

14. Deployment Status
DLC: Electrochemical Capacitors, RFB: Redox Flow Battery, H2 : Hydrogen storage, SNG: Synthetic Natural Gas
Source: Large-scale Electrical Energy Storage in Japan, Presentation by Akio Nakamura

15. Designing a storage system
Key parameters
Identify application for which storage is required
Peak Shaving
Load Shifting
Power Quality
Size of the storage system (based on capacity and discharge duration)
Cost of the system (energy cost, power cost and balance of plant cost)
Response time
Lifetime
Operability conditions
Modularity and flexibility
Maturation and commerciality
Environmental concern

16. Strategic Approach
Scope: Identify applications relevant for the entities (Grid operator/Utilities/Renewable project developer/Consumer)
Siting: Select location considering nearness to the grid/wind farm
Design: Analyze required size and type of the storage system for the required application
Development: Select cost-effective and most viable option
Pilot scale deployment
Testing: Monitoring, Evaluation, and Measurement
Commercialization: Large scale implementation

17. Barriers Financing mechanisms and Institutional framework
Siting, geographical and env. constraints
Awareness and acceptance level
Policy and Regulatory Mechanism

18. Roadmap
Installing storage for balancing the grid is a long term solution
Countries who are yet to explore renewable potential should explore potential of storage in parallel
Policy and regulatory framework should be developed to set goals and vision roadmap
Identify key stakeholders and beneficiaries
Explore public-private partnerships or other funding models
Establish centres for carrying out research and testing

19. Thank you
Questions?