energy storage technologies

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)
Sandhya Sundararagavan, Research Associate
sandhya.sundararagavan@teri.res.in
May 29th, 2014

2. Concerns / Issues
Supply-Demand Mismatch
Variability of RE Generation
Seasonal Variation in demand
pattern 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
 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: 50-60 years
 Siting/Permitting/Env. Impact issue
 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
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: 6-12 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%
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA

9. Batteries - Development
 Sodium-Sulphur
• Capacity range: 2- 10 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 300-
350 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
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA

10. Other technologies
 Flywheels
• 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
Source: DOE/EPRI 2013 Electricity Storage Handbook in Collaboration with NRECA,

11. Source: IEC White Paper, October 2012
Pumped Hydro System in Taiwan
• 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
Success Stories

12. • 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. Source: IEC White Paper, October 2012
• 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)

14. Deployment Status
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?