Transcript NAS Battery for Grid Backup - SouthWest Electric Distribution

Energy Storage
Applications at AEP
Emeka Okafor
American Electric Power
Presentation to
SouthWest Electric Distribution Exchange
May 7, 2009
Outline:
1. Challenges facing utilities
2. Energy storage to turn some of these challenges into opportunities
3. Energy storage deployment examples at AEP
4. AEP taking deployment of energy storage to the next level
Challenges to the Utility Business

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Customer-controlled renewable DG on AEP grid has grown from 1kW
to 1MW in a decade. It is expected to exceed 1GW in the next decade.
Customer renewable DG is intermittent, often not available when
needed and out of utility control.
Utilities need a buffer
between customercontrolled DG and
electric grid.
Increasing demand for
improved service quality
and reliability
PHEV load (grid impact)
Converting Challenges to Opportunities
Energy Storage:

Buffers between unpredictable customer generation and grid

Decouples load from generation

And offers other benefits as well …
2006 -
Battery in a Substation for Capital Deferral
 Installed 1MW, 7.2 MWh of NAS
battery on a feeder to defer building
a new substation for three years
 Daily Peak Shaving –summer
 Three years of operation
46 kV
bus
46kV/12kV
Transformer
12/16/20 MVA
12 kV
bus
Voltage
Regulator
Tyler Mountain Feeder
North Charleston Feeder
West Washington Feeder
Peak shaving (load leveling).
Increased Reliability with Dynamic Islanding
(Backup Power) for new installations
 Three installations (2008):
 Churubusco, IN (2MW, 14.4MWh)
 Bluffton, OH
(2MW, 14.4MWh)
 Milton, WV.
(2MW, 14.4MWh)
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Loss of power.
Pick up island.
Power electronics and communication.
Return load to grid when fault is cleared.
2008 Projects – To Improve Service Reliability
• 2MW, 14.4 MWh in Bluffton, Ohio
• Two other identical sites in West Virginia and Indiana (2008)
• All with dynamic islanding
2008 Projects – To Improve Service Reliability
2MW, 14.4 MWh in Churubusco, IN
2MW, 14.4 MWh in Milton, WV
Load Following - with new battery installations.
Benefit of Islanding – How many hours of
backup power is needed?
PERCENTAGE OF CUSTOMER OUTAGES THAT MAY BE REDUCED
WITH BACKUP POWER.
(AEP OHIO 2008)
100.00%
Customers Restored
90.00%
80.00%
70.00%
Percentage of Customers restored
within 7 hours is
95.34%
60.00%
50.00%
40.00%
30.00%
20.00%
10.00%
0.00%
1
2
3
4
5
6
7
8
>8
Hours
7 hours of backup power will ensure that over 95 percent of AEP Ohio customers
will not experience an outage.
Assumption: excludes traditional major events and momentary outages.
East Busco Station Battery Islanding Zones.
System Normal :
Grid connected. Battery disconnected.
Fault at F8; loss of grid power. All reclosers
and switches in the island open.
Battery picks up island based on last load information.
Grid power restored.
Battery disconnected. Load connected back to the grid.
Building on Success …
AEP is very pleased with the performance of its substation
batteries …
But we need to get MORE out of energy storage:
• More value to our customers
• Better cost by leveraging the electric transportation
• Better fit into Smart Grid, the way of future utilities
Community Energy Storage (CES)
CES is a small distributed energy storage unit connected to the secondary
of transformers serving a few houses or small commercial loads for:
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Uses New or Used PHEV batteries – Low Cost
Offers All Values of Substation Batteries when aggregated,
Offers Backup Power to customers
Buffers Customer Renewable Generation
Makes PHEV Charging Time an irrelevant issue
Value Associated with Storage Locations on the Grid
765 kV
345 kV
138 kV
69 kV
4 to 34 kV
480 V
CES
NAS
Devaluators:
 Limited Value to Customer
 High Security Risk
 Does not remove Grid Constraints
Central
Generation
(Community Energy Storage)
(Substation Battery)
Storage
Value
120/240 V
Devaluators:
 Aesthetics
 O&M?
Load
Distribution circuits appear to offer most value for hosting storage
CES Key Functions
Local Controls/Benefits:
1) Backup power for the local need of the few houses connected to it
2) Voltage correction
Grid Controls/Benefits:
3) Load Leveling based on substation and grid needs
4) Power Factor Correction
5) Ancillary services through further aggregation at the grid level
Integration
Platform
CES Control Hub
CES Units
CES Units
Station
Power Lines
Communication and Control Links
Figure 1
Utility Dispatch
Center /SCADA
Communication & Control Layout for CES
Advantages of Using PHEV Battery
1.
2.
Safe for public deployment
Low cost
- Fierce global competition
- US national priority
- Option to use used PHEV batteries
3.
4.
5.
6.
7.
Compact
Reliable
Efficient
Wide operating temperature
Easy recycling & lower environmental issues
Advantages of CES to Substation Battery
1.
2.
3.
4.
5.
6.
7.
Higher electric service reliability to customers
Easier installation (a 240 V appliance)
Easier maintenance (lower required skills)
More likely to be a standardized commodity
Unit outage is less critical to the grid (smaller)
Lower resistive loss in wires (closer to customer)
A better fit into the Smart Grid programs
CES Key Specifications
Most common distribution transformer size in AEP is a 25kVA unit
that serves 3-5 houses.
Key Parameters
Value
Power (active and reactive)
25 kVA
Energy
50 kWh
Voltage
120V / 240V
Round Trip AC Energy Efficiency
> 85%
Life
> 3000 cycles, 15 years
Audible Noise
< 48dBA (no fans or filters)
Size
Comparable to a 25kVA transformer
CES Cost Forecast
PHEV, and its battery development, is a US National Priority as well as
having extensive global competition
Pending the successful market penetration of PHEV, CES cost forecast
over the next five years is:

$1000 /kW
Commodity Pricing will keep this number low
$500 /kWh
PHEV penetration will push this number down
or

Putting It Together on Distribution
Utility Operations
Customer Premise
Customer
Portal or Meter
LG Electronics
PHEV
Distribution
Operations
Adapted from EPRI source image
Putting It All Together - The Virtual Power Plant
2015 and Beyond
Conclusions.
• Energy Storage will be essential to meet the
needs of the future grid.
• AEP has shown success with the use of NAS
substation battery.
• AEP sees greater value to using Community
Energy Storage to meet these new demands.
Questions?
2015 and Beyond