advanced inverter roll out in hawaii

1. Advanced Inverter
Roll Out in Hawai’i
Sandia Systems Symposium
10 May, 2016
John Berdner
Senior Director of Regulatory and Policy Strategy

2. 2
• Background
• Multi-Step Approach
• Close collaboration with Inverter industry
• Choose expediency over perfection
• Codes and Standards constraints
• Current Status and Activities
• Enphase Vision of the Future
Presentation Outline

3. 3
• Why is Hawaii the first State with mandatory requirements for
advanced Inverters ?
• The need for advanced inverter functionality are similar to those in
other high penetration areas but are magnified in Hawai’i
• Hawai’i has highest level of DER penetration of any State in the US.
• Hawai’ian grids are low inertia and inertia continues to decline as more PV
displaces conventional generation
• Voltage regulation becoming a limiting factor on some feeders
• Frequency regulation could become an issue in near to mid term.
• Modeling showed system stability and security was at risk
• AES unit trips resulted in significant frequency excursions.
• Installation of additional DER without ride through capabilities could lead to loss of
Oahu grid (tipping point)
• Political direction is for further increases in renewables
• Target of 100% RPS by 2045 set by State law
Background

4. 4
Modeling of System Stability
Graphic Courtesy of Hawai’an Electric Inc.

5. 5
Frequency Event due to AES Trip ~ 270 MW
Graphic Courtesy of Hawai’an Electric Inc.

6. 6
US Codes / Standards / Regulatory Structure
NEC Article 690.4(B) requires equipment to
be Listed for PV applications
UL 1741 is an equipment certification
Standard and references IEEE 1547.1 tests
IEEE 1547.1 is the equipment compliance
testing Standard for IEEE 1547
IEEE 1547 is the interconnection
requirements Standard
Energy Act of 2005 Mandates use of IEEE
1547 as the National Standard

7. 7
• First issued in July 2003
• Specifically prohibited DER from participation
in Voltage regulation
• IEEE 1547.a amendment published in
May 2014
• Permitted DER to participate in Voltage
Regulation
• Widened trip settings.
• Allowed other settings by mutual
agreement
• 1547.1a amendment published in
March 2015
• Test protocols to match new functionality
described in 1547.a
Regulatory Constraints – IEEE 1547

8. 8
• Second edition published in
January 2010.
• Includes references to 1547.1 for testing
and IEEE 1547 (via 1547.1)
• Contains no requirements for ride
through but does not prohibit ride
through
• Does not prohibit ramp rate control
at startup
• Allows for fixed PF operation
• Includes tests for fixed PF
• Assumed to unity but non-unity PF’s are
allowed.
• Fixed PF minimizes adverse impacts on
anti-islanding
• Does NOT include tests for V/VAr,
f/W, V/W
• Concerns over impacts on anti-islanding
Regulatory Constraints – UL 1741

9. 9
• Developed in collaboration between HEI and inverter industry
• Formed “Mai Tai” group to address Hawaiian requirements
• Step 1 - Urgently address system stability via ride through settings
• Create new frequency and voltage ride through capabilities within limits of existing
UL Listings
• A best effort approach by each manufacturer.
• Request voluntary retrofit of existing installations with new settings.
• Target was <= 40 MW of installed base with old settings.
• Enphase updated approximately 135 MW of installed base and met target (barely)
• Step 2 – Develop new ride through settings based on system need
determined by modeling
• Required new UL Listing for most inverters to address wider settings.
• Target was implementation within 9 months after agreement on new settings
• Also added TrOV requirements and ramp rate control at restart (0.33%/sec)
• Enphase completed second update to fielded fleet of ~ 800k inverters
• Step 3 – Add reactive power requirements and mandatory remote
update capabilty
• Default value is 0.95 inductive
Multi-Step Approach

10. 10
• All interconnections approved after 1 Jan, 2016 requires advanced
inverter functionality
• Voltage and frequency ride through
• Fixed PF operation (0.95 inductive/absorbing VAr)
• Ramp rate control on restart (0.33%/sec)
• Mandatory remote update capability (manufacturer specified protocol)
• NEM closed in Hawai’I for any new interconnections
• Customer Grid Supply (35 MW cap)
• Offset onsite use at retail rare, sell at near avoided cost
• Customer Self Supply (No cap)
• No export of active power at PCC
• Inadvertent export for less than 30 seconds
• Limit of 1 hr times system size montly, i.e. 5 kW system <= 5 kWh/mo.
• Inadvertent export is uncompensated
• Large backlog of older NEM applications in the queue
• Likely will carry through most of 2016
Current Status

11. 11
• Advanced inverter testing underway at NREL
• Characterization of advanced inverter functions
• Models created for several HECO feeders
• Hardware in the loop modeling of advanced inverters on HECO feeders
• Future activities will model system level interactions
• Definition of additional advanced inverter functions beginning
• New functions are allowed by UL 1741 Supplement A
• Volt/VAr (voltage droop) function and settings
• Freq./Watt (frequency droop) function and settings
• Volt/Watt function (as a backup voltage regulation function)
• Development of requirements for energy storage systems
• Similar to advanced PV inverters
• Additional capabilities due to bi-directional nature and dispatch capability
• Driven by customer self supply and customer grid supply tariffs
• New proposed TOU rates under discussion
• DER Phase 2 Docket will be opened soon to address technical,
economic and fairness issues.
Current Activities

12. 12
Network Insight
Accurate, granular, and near real-time
visibility and data
Today, Enphase has almost 50k
systems reporting in Hawaii equating
to nearly 1 million sensors reporting
every 5 minutes
Production data from distributed
resources in addition to grid telemetry
measured at secondary voltage
Enphase Vision – Data and Control
Distributed Control
Changes to advanced inverter settings
occur infrequently now but will likely
increase as penetration levels rise.
Command, control and optimization of
distributed energy resources are being
piloted now (in CA)
Advanced controls for real power,
including storage dispatch. Coordination
of real and reactive power for voltage
optimization schemes seem likely

13. 13
Capabilities:
• PV production and grid data
• Historic and near real-time data
• Multiple aggregation levels
• Revenue-grade telemetry
• Master data management
• Automated changes to advanced
inverter functions
• Storage dispatch
• Forecast/actual tracking
• Alarms and notifications
• Power quality metrics
• DR system integration
Features Available Now / Near Term
Applications
• Interconnection Studies
• DER Integration
• CVR and VVO Programs
• Customer Engagement
• System Planning
• Support DERMS Pilots