A Look at Secondary Use Energy Storage · Solar Irradiance/ PV output Residential Model Consumption...
Transcript of A Look at Secondary Use Energy Storage · Solar Irradiance/ PV output Residential Model Consumption...
A Look at Secondary Use Energy Storage
Michael Starke, PHD Oak Ridge National Laboratory
Hosted by:
FEDERAL UTILITY PARTNERSHIP WORKING GROUP SEMINAR
April 22-23, 2015 Nashville, TN
Project Overview
• Supporting the industry investigation into vehicle battery secondary-use through testing, demonstration, and modeling. – Potentially a cost competitive energy storage technology – Validate reliability and safety – working with industry to
troubleshoot and test systems under operational conditions – Examining regulatory environment – investigating hurdles
that are institutional – Industry acceptance – build confidence in this technology.
2
Secondary Use of EV Batteries
• Potentially significant electric vehicle market. – Projections from different studies
show significant growth.
– March 2014, Tesla announces news on the building of a Gigafactory with projections of 500,000 vehicle production capability by 2020.
– June 2014, Tesla is releasing all patents to encourage electric car production
• What can we do with the on-board battery technologies?
Repackage/Reuse: Could provide a low-cost grid storage solution (if design of repackaged system does not require significant modifications and added expense.)
Already Available in USA • Over 150,000 plug-in electric vehicles (PEVs) currently in USA (study
by UCLA Luskin Center for Innovation – December 2013)
– ~ 55% of PEVs are PHEV and 45% are BEV
– Near 70% of these vehicles are Nissan Leaf, Chevy Volt, or Tesla
• Leads to a an estimated 3.485GWh of existing battery storage.
• Estimates on capacity of the batteries. Detailed analysis will need to consider operational constraints, BMS level limits, and other aspects.
Nissan Leaf Nearing 40,000
Vehicles 24 kWh per pack
~960MWh
Chevy Volt Exceeding 50,000 Vehicles
16.5 kWh per pack ~825MWh
Tesla Nearing 20,000
Vehicles 85 kWh per pack
~1700MWh
Demonstration Sites: Repurposing of Batteries
• Utilizes BMW mini-E batteries and BMS/Princeton Power Systems interface hardware
• 108 kW/180kWh with DC coupling to PV
• Utilizes General Motors Volt batteries and BMS/ABB interface hardware.
• 25kW/50kWh system connected to ORNL test-bed, PV smoothing and shifting.
Current Activities
HARDWARE
SYSTEMS INTEGRATION
SOFTWARE
• Energy Storage – Used EV Batteries
• Energy Management System • Electric Grid
An effective partnership that merges equipment, technical know-how, and infrastructure:
ORNL is testing and demonstrating the technology as a third party.
The Technology
Grid Application(25kW/50kWhr)
– Expected capacity for 10 Years of Operation
– 5 Volt Battery Packs
– 5 kW per Volt Battery
– Air Cooled/Heated
Automotive Application
– Capacity for 10 Years in Automotive Application
– Power 111kW
– Liquid Cooled / Heated
GM Chevy Volt Battery
Re-Packaged
ABB Enclosure
The Working System
Grid Load
Inverter
Battery
Management
System Cell
Modem
Battery Stack
240V
1ϕ
Voltage Sense AC Input
DC Output CAN Comm.
Temperature Sensors
Voltage/Current
Sensors
Contactor Control
CAN Comm.
Interlocks
Door/Estop Sw.
Intput
Door/Estop Sw.
Intput
EstopBatt. Door
Switch
Inv. Door
Switch
Zone 1
Zone 2
Zone 3
Zone 4
Zone 5
HVAC
Unit
PV Array
Zone 1: The system has a single-phase connection with the grid, PV Array, AC breakers, islanding contactor, and voltage sensing. Zone 2: Inverter measures and senses inputs to control charging and discharging needs (4 quadrant) Zone 3: Batteries connected on DC link and controlled by BMS. BMS uses voltage, current, and temperature information to relay control information to inverter. Zone 4: Safety interlocks to prevent unsafe access Zone 5: Thermal management with fans, heaters, and HVAC. Multi-tiered layers of security are present in the
system to ensure a safe operation
Islanding Contactor
System Benefits: CES
CES
CES
CES
Subst
atio
n
Command
and Control
ISO request
(ancillary
services)
Local benefits: Real and Reactive Power Support • demonstrate that load factor and power factor can
be maintained.
Service reliability • during outage, CES unit can still supply load for a
period of time.
Phase balancing • if three units are installed (each on separate
phases) additional energy can be used to balance phases.
Grid benefits: Firming and shifting Renewables and Load leveling / T&D Deferral • battery can charge/discharge depending on
control and load behavior.
Ancillary Services • regulation/spinning
Transformer
Renewables
Bi-directional
smart meter
Junction
Box
Disconnect
switch
DC/AC
AC/DC
Converter
Repurposed
Battery
Pack
CES Unit
EV/PHEV
Similar benefits can be realized by distributed energy storage for commercial applications
Testing Setup at ORNL • ORNL objective for testing: Provide real world examination systems
integration and applications with the flexibility to capture many different case scenarios.
ORNL Distribution
System
750kVA, 13.8kV/2.4kV
Circuit #22.4kV System
750kVA, 2.4kV/480V
480V, 3 Phase, 60Hz
2.4kV, 3 Phase, 60Hz
13.8kV, 3 Phase, 60Hz 480V Distribution
Panel
Disconnect Switch
37.5kVA, 120V-240V/480V
Programmable Load Bank (240V,
Split Phase, 24kW)
Community Energy Storage (240V, Split
Phase, 25kW)
Disconnect Switch
480V, 3 Phase, 60Hz
240V, Split Phase, 60Hz
480V/2.4kV
50kW PV
50kVA inverter
15kW PV
1 Hardware 2 Communications 3 Controls
Hard/Soft: Communication and Control
Communications and Control
and Measure & Validate
• Communications and control done through Serial, Modbus over Serial, and TCP/IP
• All integrated through Matlab/Labview
• Load Bank utilized for Emulation.
DECC Facility
Communications Cable, RS232/RS485
over Modbus
Communications Cable, RS232
ORNL/Distribution
CT/VT
CT/VT
CES
ROOFTOP PV
CONTROL/COMPUTING
GRID
M&V
CT/VT
LOAD
Hardware: Equipment Inside DECC
480V/240V(split-phase) Transformer
Islanding Contactor/Relay
Programmable Load Bank
Emergency Disconnect
Battery Enclosure
Inverter
Hardware: Equipment Outside DECC
Emergency Disconnects
PV Array
Interface Set of pre-programmed controls
CES Alarms
Manual Control
State display
Controls and Programs
PV Forecast
Load Factor Control Points
SOC Estimate
text message
Cloud Cover
Solar Irradiance/PV output
Residential Model Consumption
% Cloud Cover Temperature (C)
Temperature
solarirradiance
GA Optimization
kW load
kW PV
Measured Data
Main ControlEmergency Monitoring
Data Acquistion
Load Bank
Shutoff
Data Processing
Data
Historian
Data
Load Bank Temp
Temperature (C)
Control Mode, P, Q
Storage
• Auto-runs at 12:00AM
• Controls depend on selected settings.
Measurements and Simulation Additions
• Load Bank is controlled to follow residential load profiles through macros.
Load Bank Interface
Residential Model Consumption
Macro is running
Power Consumed by Bank 1
• Residential profiles are developed through modeling and historical data collection.
Residential Modeling
Sleeping
Grooming Laundry
0.025
0.85
0.015
0.15
0.05
0.035
0.95
0.8
0.125
• Residential data has been sub-metered and collected for several years. Used to develop and validate load models.
Rin = 1/UAinsul
Tamb
Tindoor
Tmass
Cmass
Rin = 1/UAmass
Cair
QHVAC QSOLAR
QINTER
Home Model/HVAC
Markov Chains Activity Simulation
• Markov Chains are used to drive residential loads such as washer/dryer/water heaters…
PV Forecasting for Optimization
Solar Panel/Model
Cloud Forecast
Historical Data
Solar Irradiance
PV Curves
Maximum Value
MMPT (Power)
Module Temp
Ambient Temp
Solar Thermal Model
Neural Networks(Irradiance Forecast)
Collect Cloud Forecast
Weather Underground
Testing Procedure (Systems Tests) • Objectives:
– Obtain standard metrics (round-trip efficiency/ensure within bounds of standards)
– Demonstrate application examples
• Standard Metrics: – Round-trip efficiency
– Harmonics, etc.
• Applications – Load factor,
– Power factor,
– Renewable Integration,
– Islanding
Start
Charge Battery at Requested Power Level to 70% SOC
Rest Battery for 30 Minutes
Discharge Battery at Requested Power
Level for 30 minutes
Rest Battery for 30 Minutes
Time Since Last Power Level Change > 24 Hours?
At Maximum Power Level?
Increase Requested Power Level
No
Yes
No
Yes
Stop
Requested Power: 5
kW
Multiple Value Streams: Stacking Benefits (Load Factor/Power Factor, Renewable Integration)
Grid (nearly flat)
Power (W)
Time (hr)
Power (Var)
SOC (%)
Time (hr)
Time (hr) Time (hr)
Histogram power factor
Target Set to 0.97
SOC target to return to 50%
TE: PV Smoothing/Capacity Firming Objectives: Integrate PV by removing oscillations and error in forecast. Benefits: 1) Removing oscillations
in PV output can impact local voltage.
2) In some cases these oscillations lead to significant tap changes in transformers. Smoothing this behavior with storage can extend transformer life.
Power (kW)
8 10 12 14 16 18 20-6
-2
2
6
10
1403/22/2014
Time (Hr)
Pow
er (
kW
)
Total PV Power
CES Power
Net Power
Predicted PV Power
Power (kW)
TE: Islanding Mode Objectives: Utilize storage for emergency backup power Benefits: 1) Provides power during
an outage 2) Can be used to
support contingency type events as well to reduce load consumption.
Grid power
Battery-supplying
entire load
Initial Economic Approach
(Mixed Integer) Linear
Optimization Grid
Services
Battery Model
Data
Optimal Battery
Dispatch
Cost/Savings
• Arizona Public Service Company residential rate structures • Year-long simulated load for 3 homes • Dispatch the battery to minimize the homeowners’ cost • Utilized efficiencies of real system, 10year/3000 cycle
battery
Initial Economic Results
Initial Economic Results
Future Tasks
• Modeling and economics assessment for DES.
• Development of refurbished secondary use ES.
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L1
L2
L3
S11
S12
S21
S22
S31
S32
C3
C2
C1
S1 S2 S3
S4 S5 S6
BMS
BMS
BMS
V1
I1
V2
V3
I3
Va
Vb
Vc
G12
G11
G21
G22
G31
G32
G1
G2 G3
G6G5G4
G11, G12
G1, G2, G3, G4, G5, G6
Estop1, SOC1, kWh1, kW1
Estop1, SOC1, kWh1, kW1
DC/DC Converter 1
V1, I1
Va, Vb, Vc
Ia, Ib, Ic
Inverter Control System
Preq, Qreq, Mode
DC/AC Inverter/Grid Connection
G1
La
Lb
Lc
Battery
I2
Battery
Battery
Ia
Ib
Ic
3ϕ 480VAC
600VDC
<500VDC,
25kW
L4
S41
S42
BMS
V4
I4
G41
G42Battery
L5
S51
S52
BMS
V5
I5
G51
G52Battery
<500VDC,
25kW
<500VDC,
25kW
<500VDC,
25kW
<500VDC,
25kW
C4
C5
100kW