Energy Storage - Alaska Power Association

Energy
Storage
Energy Storage
Alaska Power Association
Alaska Power Association
Annual Meeting
August 10, 2012
Brad Reeve
Kotzebue Electric Association
Kotzebue Electric Association

KEA
�Off grid
�Diesel and wind powered
�Started wind program to reduce
diesel consumption
�First wind turbines installed in
1997

KEA
�Average load 2.5 MW
�Installed wind 2.94 MW
�Storage designated = 2.8 MW
� 500 kW output – 7 hours
�Premium Power Transflow 2000

Wind Farm Expansion
Prior Status
17 wind turbines
1.14 MW installed Capacity
~ 90,000 gallons of Diesel/yr saved
Current Status
2 Additional Turbines 900 kW
in size
2.94 MW installed Capacity
Wind Expansion with Battery Storage has the potential to
save an over 300,000 gallons of diesel per year!

Advanced Battery Breakthroughs
� Long Life (defined by number of charge and
discharge cycles)
�Cycle lifetime of 5,000 to 10,000 cycle is now
possible
�Charging and discharging daily implies 300 or
more cycles a year, 9,000 cycles in 30 years
� Costs have decreased by 30% to 50%
�$2,000/kW now for 7 hours of storage instead of
$3,500/kW
� Large battery complexes are being built in >1 Mw
sizes
� Acceptable efficiency of 70% or more

Battery NRECA/Kotzebue
� KEA was in the process of acquiring a VRB
Vanadium Redox Battery
� We were in final design when the company
went into bankruptcy
� In 2008 NRECA’s Cooperative Research
Network applied for a American
Reinvestment and Recovery Act (ARRA)
stimulus grant (50/50 match) to purchase and
test flow batteries with 3 other cooperatives

Vanadium Redox Battery (VRB)

Prudent Energy
Vanadium Red‐ox Flow
Battery

Battery NRECA/Kotzebue
� ARRA grant was not approved
� KEA continued to proceed with a project
� Kauai Electric intended to firm solar power
� Seminole Electric intended to avoid the need for
a new substation
� Several utilities were looking at arbitrage
solutions
� KEA’s intent is to increase diesel/wind plant
efficiency and needs longer term storage

Energy Storage
� Stabilize power from wind turbines
� Ability to store energy from high wind events
(Time shift wind energy to daily peak for fuel
savings)
� Allow operation of diesel generators in zones
of maximum efficiency
� Potentially allow us to operate system in diesel
off mode during warmer months
� Frequency regulation and spinning reserve
� Potental of emergency power and blackstart

Basic Zinc-Flow Technology (Plating
and de-plating of Zinc)

TransFlow - 2000
Utility-Scale Mobile Energy Storage
Battery Output
2.8 to 3.4
Megawatt Hours

Premium Power TransFlow 2000
Zinc Bromide battery on a trailer 500 kW, 7.4
hours and 3.8 MW -Hr & ~$1 million

Stacks and Pumps

In the assembly area. These are the electrolyte tanks.

Power attachments to battery

Why KEA is interested in the Premium
Power Zinc Bromide Battery?
� Lifetime of more than 10,000 cycles of deep
charge and discharge
� Lowest cost battery of all the advanced options
based on CRN due diligence report
� Potentially very low environmental impacts
� PPC ZnBr is UL, FCC, and NFPA certified
� The PPC ZnBr batteries are made in the U.S.
� PPC is well capitalized.
� PPC ZnBr has the potential for fast frequency
regulation and nearly unlimited cycle life.

Energy Storage (kWh) Comparison
Method $/kWh Power
(MW)
Pumped
Hydro
Compressed
Air
NaS (NGK) 2,500-
4,500
Efficiency Lifetime
(hours)
250-260 20-2,400 76-83% 11,000+ 10
550-650 110-290 50-75% 11,000+ 10
.05-50 70-80% 3,000+ 7
Ni-Cad 610-1,700 .01-27 60-65% 1,000+ 4
Premium
Power
350-400 .5 70% 30 years 5
ZBB 1,070 .5 77-78% +2,000
cycles
Prudent
Energy
1637 Varies 85% 10,000+
cycles
Discharge
Time
(hrs)
varies
varies

Power Stability (kW) Comparison
Method $/kW Power
(MW)
Lead Acid 1,050-
1,890
Flywheels 2,500-
4,000
Super
Capacitors
NaS
Batteries
Li-Ion
Batteries
Efficiency Lifetime
(hours)
.01-10 70-75% 250+ 15
.5-1 90-95% 500,000+ 15
Discharge
Time
(min)
n/a .003-.01 90-98% 500,000+ Seconds
3,000-
4,000
1,000-
4,500
Lead Acid 1,050-
1,890
.05-50 70-80% 3,000+ 300
.005-1 90-95% 20,000+ 15
.01-10 70-75% 250+ 15

TransFlow - 2000
Current Status
� Maturing Core Battery technology for manufacturing
scale-up
� Expanded test program has been implemented
� Consulting experts retained to assist in analysis and
technology refinement
� Special test equipment devised to characterize/optimize
component performance
� Extended system cycling operation required to identify
reliable operational parameters
� In-depth manufacturing process assessment for quality
improvements

TransFlow - 2000
Current Status
� TF 2000 Trailer configuration impractical
� High density/compact design difficult to service
� Transportation induced equipment damage
� Limited shipping options and high cost
� ISO Container design and implementation
underway
� Evaluating supply chain for power electronics and
microgrid controls

Next Steps
� KEA did not accept ownership of the unit
� TF 2000 Trailer system will be replaced with a
container system with each quadrant in a
separate container
� Replacement unit is scheduled for summer 2013
delivery
Thank You