1. REDT Vanadium Redox Flow Battery (VRFB)
‘Firming Up’ Wind Energy & The DECC Gigha Project in Scotland
Meitheal Na Gaoithe Conference, Kilkenny
John Ward, REDT Energy Ltd. Dublin. 1

2. Agenda
Background to the Technology Development
VRFB – What is it ?
Review of VRFB technology - performance at stack level and scale up to grid systems
Applications in Brief & Progress to date
Demonstration Project – Gigha
Conclusion

3. Key features for reliability:
VRFB – What is it ?
Key features for reliability:
Power and energy independent
Scalable from 5kW to 10MW, with
3 to18 hours discharge duration
Deep discharge capability
Capable of 10,000 cycle life with
minimal degradation >20 year life
Partial cycles have no effect on system life
Safe operation
Ambient temperature, non-
flammable, environmentally sound
– zero emissions.

4. Vanadium – What is it ? The 23rd element in the periodic table
23 P N
Electron shells
Vanadium is a silverish transition metal (the valence electrons exist in more than one shell). In normal states, vanadium atoms have 23 protons, 23 electrons, and 28 neutrons. Very High Columbic Efficiency -98%

5. VRFB 5kW Stack – Building block
All polymer materials, high integrity sealed system Low impedance
membrane electrode structure
Charge/discharge ratio 1:1
5kWe nominal,
8.5kWe peak (15 mins)
Future target of 15kW

6. Vanadium Redox Flow Battery Benefits
Low LCOE >20 year life
Lowest cost over life in class
Modular from 5kW to 5MW to match loads, scale duration from hours to days
Stack life > 10,000 cycles, electrolyte indefinite life, re-usable & recyclable
Performance
Deep discharge cycles, uses 100% of available capacity
Charge retention, almost indefinite in standby mode
75-85% round trip efficiency
Partial cycles have 0 effect

7. Timeline of development
Low cost manufactured product launch phase
2000: REDT Started
: Small 5kW stack developed
2012: Technology proven
2013: Large stack 1.2MWh order
2014: Low cost outsourced manufacturing
JABIL
Demonstration phase
: Volume production
Automation
Large volume
R&D cost down
R&D phase
2014: 7 units
10 demo unit facility launch
Tested quality process production
R&D cost down plan
2013: 60kWh system in Portugal

8. Original 30kWh VRFB pilot system – 2011

9. Containerised modular VRFB system designs -standardised for volume production
5-30
10-30
5-60
10-60
15-180
30-180
45-180
60-180

10. ISO Standard 20’ container section – 60kW x 180kWh
12 x 5kW rated stacks per battery
Insulated air flow thermal control system
Argon blanketed electrolyte
Safety – leakage, fire, hydrogen detection
96,000 Litres of electrolyte per container
Excess electrolyte enables deep discharge

11. The Isle of Gigha and the Application
Community owned Wind
Population ~150
Tourism, Farming, Brewing
Renewables potential
Sub-sea cable
One of the longest 11 kV feeders to mainland
Remote and wild

12. Regional Context – The Western Isles
Argyll generation severely constrained
SSE cable upgrades scheduled for 2015
Test site for VRFB selected by CES

13. The Isle of Gigha and the Application
Current position:
New (4th) wind turbine installed -
exceeds T&D limits
330 kW constrained to 225 kW at 0.85 p.f.
Line capacity upgrades not yet available
Lose 3 GWh over asset life
Primary objective:
Constrained energy recovery with on- peak dispatch
Enhanced FIT benefit
Opportunity to increase RE generation by 30%

14. VRFB Applications – Grid balancing services
Typical Energy Storage application for grid peak shaving with baseload power

15. Parker SSD EGT Control System
Parker SSD PCS working with the REDT VRFB has a system response time of less than 5m/s and can therefore perform multiple intra-cycle control functions. Electronics and cable inductance are limiting factors not the energy storage system itself.

16. Firm Frequency Response (FFR) Profile Gigha 105kW rated system - RoCoF

17. Short term operational reserve (STOR) Profile

18. Arbitrage Profile

19. Constrained Energy Profile – Typical day Gigha system 105kW x 1.26MWh
Blue = ESS kW, Charging when negative Red = Stored energy MWh zero SOC

20. System Services Summary
Frequency Control
Voltage Control
Regulation of Curtailment
Arbitrage
Improvement of output prediction
Post demonstration stage the technology will be rolled out to other islands

21. Energy storage is entering the mainstream
Conclusions
Energy storage is entering the mainstream
The Technology is constantly evolving and becoming cheaper – full suite of services and dispatch for c.5 euro/Mwh
REDT will be ready for large scale deployment supporting wind energy & Solar in Q3 2015
Within 5 years there will be large scale deployment of distributed storage worldwide
Market for storage globally is $10Bn by 2017(19), 33% of this is estimated to be flow batteries
Possibility of an entirely renewable power system…?

22. Thank you for your attention – Questions ?