distributed generation and impacts to distribution...
TRANSCRIPT
Distributed Generation and Impacts to
Distribution Systems
FMEA Energy Connections Conference 2017
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Biographies
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Matt Lundeen has a BSEE degree from the University of Florida and is currently pursuing a MSEE degree specializing in Power and Energy from the New Jersey Institute of Technology. Matt has over 12 years of utility experience with background work including distribution engineering, key account management, and managing a team of engineers performing various electric system power quality and reliability analyses on the JEA system. Matt’s current role is to effectively lead a team implementing projects that improve the reliability and power quality of the electric distribution system at JEA.
Trishia Swayne is a registered professional engineer with 13 years of experience in electric utility system planning and consulting. She obtained a Bachelor of Science in Engineering Physics and a Master’s Degree in Business Administration at Murray State University in Kentucky. She leads a team at Leidos that performs DER interconnection impact studies and distribution planning services such as capital improvement plans, voltage optimization, and system protection and coordination studies for utilities across the United States and the Caribbean islands.
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Outline
JEA Electric System Overview JEA History with Solar Solar Policy New Solar Projects Solar Challenges with Operations Net Metering Net Metering Policy Challenges Policy Revisions for DG Future Preparations Electric System Potential Impacts of Distributed Generation Study Methodologies in Case Study Study Outcomes in Case Study Conclusions
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JEA Electric System Overview Part 1 JEA is a vertically-integrated electric utility Established in 1883, JEA is the nation’s 8th largest community-owned
municipal utility
Service Territory Approximately 900 square miles All of Duval County; a portion of St. Johns County and Clay County
~474,000 retail electric customers served Combination of residential, business and industrial Wholesale service to the City of Fernandina
System Peaks (Instantaneous) Winter 2009/2010: 3,250 MW Summer 2007: 2,937 MW 2017: 2,505 MW(w); 2,727 MW(s)
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JEA Electric System Overview Part 2
Net Assets In-Service: $3.7 billion
Power Production Assets 6 Plant sites*, 18 Units*
Net Capacity (2017): 3,769 MW (4,110 MW winter) Fuel sources: Oil, Natural Gas, Coal and Petroleum Coke Small amount of renewables (solar and landfill gas)
Transmission System Voltage levels (KV): 500, 230, 138, and 69 745 miles of transmission 74 substations; 200 transformers (high side >= 69kV)
Distribution System Voltage levels (kV): 26.4, 13.2 and 4.16 336 feeders (214 - 26.4 kV; 95 – 13 kV; 27 – 4 kV) 6,760 circuit miles (45% overhead; 55% underground) 102,600 transformers; 200,900 poles
5 5* = Includes St Johns River Power Park and Plant Sherer (Jointly Owned)
JEA History with Solar
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1999-2003 22 Duval County public schools Jacksonville Zoo Jacksonville Chamber of Commerce Jacksonville International Airport Jacksonville University FSCJ COJ Fire Rescue Station JEA downtown parking
2010 – JEA’s Jacksonville Solar Project 12MW(AC) solar generation facility PPA (Purchased Power Agreement) for 31 years Fixed array PV panels situated on 100 acres
adjacent to JEA’s Brandy Branch Generation Station
FSCJ – Florida State College of Jacksonville COJ ‐ City of Jacksonville PV – Photovoltaic
JEA Existing Photovoltaic Resources
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End of CY2016 Solar Portfolio
Program Size (MW)Annual Energy
(MWh)
JEA Solar PV 0.2 128
JEA Solar PPA 12 21,000
Net Metering 6.0 8,300
Total 18.2 29,428
Solar Thermal 5.5 2,300
Total 23.7 31,728
Solar Policy Key Points
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Policy Highlights Add up to 38 MW of solar photovoltaic (PV) Purchase agreements (PPAs) Include utility-scale and smaller solar-garden scale Customer offerings are being developed Sites offer geographic diversity within the service territory PPA offer to take advantage of 30% federal tax credit
End of CY2017 Interim Target Solar Portfolio
Program Size (MW)Annual Energy
(MWh)JEA Solar PV 0.3 200
JEA Solar PPA 12 21,000
New Solar PPAs 32 75,686
Net Metering 10 13,140
Total Solar PV 54.3 110,026
Solar Thermal 5.5 2,300
Total Solar 59.8 112,326
JEA Solar Portfolio Will be 4.7 times 2014 levels by the
end of 2017 Approximately 1% of JEAs total energy
New Solar EnergyJEA Solar Contracts
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No. Project Company MW Status
1 Jacksonville Solar Jax Solar 12 Online
2NW JAX Solar Partners Farm*
groSolar 7 Online
3 Old Plank Rd Solar Farm VeloSolar/COX 3 Online
4 Starratt Solar Inmansolar 5 Under Constr.
5 Blair Site Solar Hecate 4 Site Clearing
6 Simmons Rd Solar Inmansolar 2 Permitting
7 Sunport Solar Farm NationalSolar 5 Permitting
8 Old Kings Solar MirasolFafco 1 Permitting
Total Solar Capacity 39 MW
*Formerly referred to as Montgomery Solar
Solar PV Challenges for Operations
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0 3 6 9 12 15 18 21 24
MW
Hour
Clear
Few
Scattered
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Overcast
Sky Condition MWH/Day % Output Days % of Year
Clear 95.4 100% 53 15%
Few (10% sky covered) 73.7 77% 41 11%
Scattered (10% - 50% sky covered) 63.1 66% 100 27%
Broken (60% - 90% sky covered) 49.2 52% 129 35%
Overcast (100% sky covered) 16.8 18% 42 12%
MWH % Output
Total Output (If 100% Clear) 34,805 100%
Total Output (2013) 21,183 61%
Losses Due to Weather 13,621 39%
JSI Performance by Weather Type
1000
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3000
1 3 5 7 9 11 13 15 17 19 21 23
MW
Hour
Summer Peak DaySystem Load
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Winter Peak DaySystem Load
10PV – Photovoltaic JSI – JUWI Solar Inc
Net Metering
Program started in 2009
Put in place to test and incentivize the emerging customer-owned solar market
Incentives result from utilities’ paying customers for all excess generation at the retail rate
Solar system buyers also receive a 30% Federal tax credit for the value of their purchase.
428 of the 1,276 net metering customers were installed in FY17 – approximately 34%
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Net Metering Policy Challenges
The existing Net Metering policy creates an unsustainable cost of service recovery condition within the residential rate class. Energy delivered to JEA is purchased at
full retail (~$0.11) versus avoided cost which is essentially the fuel rate currently around $0.0325 per kWh.
Impacts recovery of the fixed assets associated with owning and maintaining the infrastructure of the generation fleet, transmission, and distribution systems through the variable per kWh consumed energy charge.
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Policy Revisions for DG
Revised Policy approved in October 2017 - pay fuel rate for energy sent to JEA.
Introduced Battery Incentive Program to encourage customers to store excess energy, preserving customer economics.
Considering possible rate structures to more accurately reflect cost structure such as solar rate derived from JEA cost of solar, and a residential demand rate.
DG – Distributed Generation 13
Keeping Up With the Pace
IEEE 1547 Updates Working Group targeting Q2/Q3 of 2018 for publishing revised
1547 standard
Smart Inverter Working Group/Rule 21 Phase 1 has been adopted and autonomous functions established
in phase 1 are mandatory after September 8th, 2017
Phase 2 and Phase 3 are currently being worked on by the SIWG
JEA Interconnection Requirements Updates Revising interconnection standards based on project experience
where TrOV exists using existing 1547 standard and to incorporate Smart Inverter capabilities
14TrOV – Transient Overvoltage
Distributed Generation Potential Impacts
Thermal Loading Short Circuit, Protection, and
Grounding PQ Implications such as Flicker Unintentional Islanding/Safety Dynamic Stability System Upgrades TrOV Substation Transformers Load Tap Changer Operations Load Flow and System Planning
Afternoon Storm
15PQ – Power Quality
Case Study Methodologies
Case Study 7 MW PV site 26.4 kV distribution circuit Existing rooftop penetration of PV = 168 kW Peak daytime load = 10.4 MW Light daytime load = 2.5 MW
16PV – photovoltaic
Case Study Methodologies
Voltage Flicker
Steady State Analysis
Short Circuit and Protection
Capacity, voltage, power factor, reverse power flow, tap movement
Device ratings, effective grounding, reclosing, coordination
Risk of Islanding Sandia Report Screening method
Analyses Comments
Voltage fluctuations due to intermittent source
Transient Analysis Load rejection, ground fault, in-rush, overvoltage
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Case Study OutcomesReverse Power Flow – No concern
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Case Study Outcomes
Steady State Analysis Existing low voltage not exacerbated by Project One LTC tap movement at peak with Project Power factor at substation acceptable (> 95%) Capacity violation on tap to Project site; 5 miles upgraded
to 636 aluminum
19LTC – Load Tap Changer
Case Study Outcomes
Voltage Flicker Pst and Plt evaluation - acceptable Single worst case event = 3.81%; is a concern
20Pst – Short Term Flicker; Plt – Long Term Flicker
Case Study Outcomes
Short Circuit and Protection Fault contribution 18% of maximum fault current at POI Two upstream devices between the feeder relay and POI; 65T fuse and
recloser (see next slide) Need to move overloaded fuse downstream of POI Fast curves of recloser do not leave margin for a POI site recloser; recommend
upgrade to electronic and slow down fast curves Reclosing at feeder relay to start at 2 seconds or beyond
21POI – Point of Interconnection
Case Study Outcomes
Short Circuit and Protection
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Case Study Outcomes
Risk of Islanding – Sandia Screening Method Results in negligible risk Red flag is PV penetration concerns
Circuit 393 PV/Load = 294% Circuit 393 Midstream recloser PV/Load = 740% Red flag is PV penetration concerns
Next steps – Transient analysis in PSCAD™
23PV – photovoltaic
Case Study Outcomes
Transient Analysis Load rejection (feeder and mid-stream recloser) Ground fault analysis Energization (in-rush) analysis
Note: Follow Transient Overvoltage (TOV) criteria from IEEE 1547 Transient Overvoltage Curve (draft)
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Case Study Outcomes
Load Rejection • Violation with
transient overvoltage with midstream recloser event
• Solution requires inverter to have instantaneous response to voltage violations
Source Current : Graphs
sec 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80 1.90 2.00
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40 VintPOI
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Conclusion
Key Takeaways Importance of customer education – as it pertains to various
technologies such as PV...to better understand foundation of policies developed by utilities and/or PUC’s/PSC’s/Boards
Set priorities on keeping up with technologies/markets and how that may impact standards/policies/internal procedures/operations etc
Good data for studies is key Even minor mitigations determined in studies could lead to major
operations and reliability issues
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