prepared for the south carolina public service commission
TRANSCRIPT
South Carolina Interconnection and Distributed Energy Resource UpdatePrepared for the South Carolina Public Service Commission Workshop - December 15, 2016
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j5 DUKEP ENERGY.
Review Areas
1. DER Program Update2. Interconnection Processes,
Challenges, and Improvements3. Operational and Technical
Challenges of Large Solar Generators
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Duke Energy Carolinas
Duke Energy Progress
1. DER Program Participation Updates
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Duke Energy South Carolina Distributed Energy Resource (DER) Goals
Duke Energy CarolinasDistributed Energy Resource (DER) Program Goals
Before 2021, DEC will Procure 40,000 kW of solar
power from facilities 1,000-10,000 kW in size via RFP
Incent 40,000 kW of customer-sited solar power from facilities less than 1,000 kW via rebates, including ~10,000 kW from solar facilities less than 20 kW in size.
Upon completion of the above, the company has the option to invest in an additional 40,000 kW of solar power from facilities 1,000-10,000 kW in size
Duke Energy ProgressDistributed Energy Resource (DER) Programs Goals
Before 2021, DEP will Procure 13,000 kW of solar
power from facilities 1,000-10,000 kW in size via RFP
Incent 13,000 kW of customer-sited solar power from facilities less than 1,000 kW via rebates, including ~3,250 kW from solar facilities less than 20 kW in size.
Upon completion of the above, the company has the option to invest in an additional 13,000 kW of solar power from facilities 1,000-10,000 kW in size
40,000 kW
+40,000 kW
+40,000 kW120,000 kW
13,000 kW
+13,000 kW
+13,000 kW39,000 kW
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DER Program Update – Rebate Program vs. Act 236 Goals
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Duke Energy ProgressRebate Program Status - as of Nov. 16, 2016
Solar Installation Size
Rebate Application –total capacity for which customers have applied
Act 236 Goal
If all solar facilities that receive rebate are built, will Act 236 Goal be met?
Small Facilities (less than or equal to 20kW)
820 kw At least 3,250 kW*
No. Just 25% of small scale-goal has been met so DEP is still encouraging rebate applications
Large Facilities (greater than 20kW and less than or equal to 1,000kW)
9,900 kW At most 9,750 kW
Yes. Large Facility goal of 9,750 was met so Large Solar Rebate Wait List established.
Total 10,667 kW 13,000 kW No
Duke Energy CarolinasRebate Program Status - as of Nov. 16, 2016
Solar Installation Size
Rebate Application –total capacity for which customers have applied
Act 236 Goal
If all solar facilities that receive rebate are built, will Act 236 Goal be met?
Small Facilities (less than orequal to 20kW)
14,500 kW At least 10,000 kW*
Yes. 140% of small scale-goal has been met so Small Solar Rebate Wait List established.
Large Facilities (greater than 20kW and less than or equal to 1,000kW)
32,000 kW At most 30,000 kW
Yes.Aggregate goal of 40,000kW was met so Large Solar Rebate Wait List established.
Total 46,500 kW 40,000 kW Yes
**Duke may incent beyond 3,250 kW provided the aggregate total of small and large facilities does not exceed 13,000 kW, per Act 236.
*Duke may incent beyond 10,000 kW goal provided the aggregate total of small and large facilities does not exceed 40,000 kW, per Act 236.
DER Program Update – DER NEM Incentive Program
Duke Energy CarolinasNEM Program Status - as of Nov. 16, 2016
Rider Name
Number of customerswho have elected to net meter
Cumulative capacity of net metered generation
NEMStatutoryLimit*
Installed capacity as a percentageof utility’s retail SC peak
Rider RNM 1,241 customers 10,182 kW - -
Rider NM-SC 223 customers 2,495 kW - -
Total 1,464 customers 12,677 kW 80,000 kW 0.32%
(limit = 2%)
6*Per state law, (South Carolina Code Section 58-40-20 (B)) utility may limit net metered generation to two percent of their respective previous five-year average retail South Carolina peak demand. For DEC 2% = 80,000 kW-AC; DEP 2% = 26,000 kW-AC.
Duke Energy ProgressNEM Program Status - as of Nov. 16, 2016
Rider Name
Number of customerswho have elected to net meter
Cumulative capacity of net metered generation
StatutoryLimit*
Installed capacity as a percentageof utility’s retail SC peak
Rider RNM 60 customers 480 kW - -
Rider NM-SC 11customers 181 kW - -
Total 71 customers 661 kW 26,000 kW 0.051%
(Limit = 2%)
UTILITY METER
2. Electric utility measures energy output of array each month and transmits that to the Utility Billing System
UTILITY SYSTEM
3. Electric utility system transmits energy to all customers
UTILITY BILLING SYSTEM
4. Utility Billing System determines how much of the shared solar array’s kilowatt-hour output should be credited to each subscribing customer, based on his/her fractional share of the array, then applies a credit of ~6¢ per kilowatt-hour.
SHARED SOLAR SUBSCRIBERS
5. Subscribing customer pays electric utility bill, as usual, for electricity consumed each month. Also pays subscription fee for access to solar power. Then receives bill credit of ~6¢ per kilowatt-hour for his/her share of the actual solar energy produced at shared array, each month.
SHARED SOLAR ARRAY
1. Solar farm produces energy when sun shines
DER Program Participation Update – Shared Solar Program
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Duke Energy anticipates that the Shared Solar Program will be available to retail customers by late 2017.
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Utility Scale Solar Goal Update
53,000 kW* sought through Request for Proposals (closed Oct 2015) To-date 5,000 kW contracted Most bids seek to interconnect large solar farms (average size: 8,000 kW = 40 acres
of solar PV) to rural distribution circuits (average size: 12 kV). Bid evaluation based on economic value and technical feasibility
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Duke Energy is engaging bidders to find solutions to interconnection of proposed solar farms on distribution circuits; Tier I completion in 2018
*53,000 kW represents DEC+DEP (combined) Utility-Scale Solar Goal, per Act 236
2. Interconnection Processes, Challenges, and Improvements
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1. Renewable generator submits Interconnection Request (IR) and associated documents
2. Utility notifies generator of receipt of documents
3. Utility confirms that documents are in order, notifies generator again
4. Utility confirms that capacity is available on that line segment.
5. Generator/ Customer signs Intercon-nectionAgreement
6. Generator constructions facility
7. Utility or county inspects solar facility; utility sets meter, generator is energized
Process for Generators Less Than 20 kW is Relatively Straightforward
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A. Interconnection Request Application
B. One-Line Electrical Diagram of Generating Facility
C. Proof of Insurance D. Inverter Equipment
Spec Sheet
E. Generating System Equipment Spec Sheet
1. Renewable generator submits Inter-connection Request (IR)
2. Utility notifies generator of receipt of documents
3. Utility confirms that documents are in order, notifies generator again
2. Utility evaluates generator against approved inter-connection procedure such as Pre-App, Fast Track, Supplemental and/or Full Study
3. Utility provides scope, cost, timeframe of interconnection study to generator
4. Generator responds to utility with proceed/do-not-proceed instructions
Utility provides Intercon-nectionAgreement (IA); Generator signs IA
5. Utility builds intercon-nectionfacilities as well as any System Improvements necessary for safe, reliable interconnection
6. Generator constructs facility, commissions it; utility and/or county inspects, generator is energized
Large Generator Interconnection Requires Additional Detail, Time, Care
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A. Interconnection Request Application Form
B. Applicable Fee / Deposit Submitted with Request
C. Demonstrated Site Control Form
D. Site Plan of FacilityE. One Line Electrical
Diagram of Generating Facility
F. Inverter Equipment Specification Sheet
These processes are typically the most labor-intensive and most time-consuming due to the need for communication between proposed generator and utility
System Impact Study
• Operating Impacts• Circuit Capacity• Other Projects• Circuit Design• Project Size• Operating Profile
• System Upgrade Requirements
• Interconnection Facilities• Protection Requirements
• Scope of Interconnection• Cost of Interconnection• Estimated Timeline
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Complete SystemImpact Study for
Project
Duke Energy Interconnected >700 Small Renewable Generators in 2016
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0
200
400
600
800
1000
1200
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2,000
4,000
6,000
8,000
10,000
12,000
2011 2012 2013 2014 2015 2016
# of
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Cumulative Renewable Generation Interconnected, Duke Energy South Carolina, 2011-2016
renewable capacity (kW-ac) # of generators
From submission of IR to setting of meter, DEC and DEP average 50-60 days.
Interconnection Requests from Large Solar Generators Soared in 2016
DEC DEPSolar 465,851 1,154,487Non-solar 5,570 -
0
200,000
400,000
600,000
800,000
1,000,000
1,200,000
Kilo
wat
tsLarge Generators (greater than 20 kW) in Duke Energy South
Carolina Interconnection Queue, as of 12/5/2016
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More than 600,000 of the kilowatts shown above are independent power producers whose generation is unrelated to Act 236.
Most Generators are interconnected within 90 days
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17.1%
48.1%
75.2%
89.4% 94.7% 97.1% 98.1% 98.7% 99.3% 99.5% 99.7% 100.0%
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IRs
Days Required to Interconnect South Carolina GeneratorsHistorical Review of Interval from IR Receipt to Interconnection
# generators % of total number of generators interconnected
Duke Energy has successfully interconnected almost 90% of all generators within 120 days.
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View of Today’s Large Generator Interconnection Queue
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98
77
29 30
114
-
20
40
60
80
100
120
IR Processing Fast Track Study System Impact Study Facilities Study Contruction Phase Completed Projects Withdrawn
Current Status of Generators in SC Interconnection Process
Total
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SC Interconnect Study Intervals (Jan. 1, 2016 – Sept. 30, 2016)
The average interval for studies completed in 2016 is trending at 60 business days and represents studies entering the queue prior to the new standards 17
Factors that Impacts to Time Required to Process Interconnection Requests
Queue Volume: Number of and Timing of New Interconnect Requests Interdependency with Other Proposed Generators in Queue Point of Interconnection: Is generator interconnecting as net metered facility
or sell-all? On distribution or transmission system? Operational Parameters: Generator details (size, expected output) and
System Details at Interconnection Point (e.g., near Voltage Regulator?) Operational Impacts: Location of Project Point of Interconnection (e.g.,
Circuit Stiffness Ratio) Business and Communication issues: proposed generator option sold to
another party; utility not notified and cannot contact new owner of solar option
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Interconnection Organization – Distributed Energy Technology
RSCSmall Customer Process
IR Process Thru 10-day Letter Notice
OperationsStudy Process Oversight
Data Management Reporting Support
Billing Support
InterconnectionProcedure Oversight
Agreements and ContractsCoordination for Project Completion
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Interconnection Process Improvements: Organizational Changes
Distribution Planning Team 5 engineers dedicated to South
Carolina interconnection studies
Transmission Engineering Team 2 engineers dedicated to South
Carolina interconnection studies
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Interconnection Team Created Interconnection Account
Management unit tasked with communicating with the proposed generator (current: 10; future 17)
Created Interconnection Operations unit (current 10; future 13)
Duke Energy continues to hire additional employees to meet the demand for interconnection
Interconnection Process Improvements
Industry Education South Carolina Solar Council
Meetings – 100+ participants Webinars for Solar Installers – 100+
participants Quarterly DER Collaborative
Meetings
Customer Education & Assistance Renewable Service Center customerownedgeneration@duke-
energy.com Tel. 866.233.2290 (8am-5pm, M-Fri)
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Online Application PowerClerk online available for
Small Generators less than 20 kW
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Process Improvement: Implementation of Salesforce Software
Salesforce is an online database software product customized to Duke Energy’s interconnection needs
Use of single database improves data quality and integrity for: Compliance with Record
Retention Policy Customer Communication
Record Customer/Developer Reporting
(possibility for Dashboard Interface)
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$1.7MM enterprise investment Over the next 6-12 months,
Salesforce will: Enable Duke to launch online
Interconnection Request for Large Generators (no more paper applications)
Will automate communication to proposed generators, deadline management, form and agreement management, and exception processing
salesforce
Interconnection Process Improvement: Visibility
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Duke Energy makes available (and updates twice monthly) a report for developers of Large Scale Solar Generators, showing their progress through the queue
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Interconnection Queue
The Duke Energy mterconnection queue reflects the status of generators that have requested
mterconnection at distnhution voltage levels with generation capamty greeter than 20 kW
Ths t connect on q e mpon s pd ted on the 15th d 30th ot e ch mo th
Queue Report (Excel file) Queue Report (PDF)
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3. Operational and Technical Challenges of Interconnection of Large Solar Generators
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Power Quality Events Prompted Discussion of Long-Term Sustainable Approach to Interconnection of Large Solar Generators
Background DEP on the leading edge: 1500+
megawatts in DEP interconnected today; industry Standards (e.g., IEEE) are not fully developed for large-scale solar generators
DEP has experienced multiple events indicating the necessity for more sustainable approaches to interconnection of large solar generators
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It is incumbent upon Duke Energy to innovate sustainable approaches to interconnection of large solar generators on distribution circuits
US planned utility-scale solar projects in advanced development or under construction
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Duke’s experiences with stand-alone solar
Starting in late 2015 and especially in 2016, we have started to experience unexpected events Voltage harmonics induced from transformer magnetizing inrush
(unrelated to inverters) Impacts experienced to nearby industrial customer
Inverter sensitivity to capacitor switching Impacts voltage & utility equipment
Harmonic production from inverters during magnetizing inrush Impacts to customer equipment
Inverter phase angle instability Impacts to voltage
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Seeking a sustainable interconnection approach for stand-alone solar generators
Large solar generator investments are built to maximize kWh output exist solely to generate energy for
sale are stand-alone, not associated with
a load; are non-dispatchable, with
intermittent output; do not provide ancillary services or
system support services like voltage and regulation
Distribution system investments are built to deliver high quality, 24-7
reliable energy to consumers
Sustainable approach Locate such facilities at “stiffer”
parts of the system, where they have less potential to cause undesired impacts
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Circuit Stiffness Review and Advanced Studies
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CSR (Circuit Stiffness Review) is a screening evaluation which considers the ratio of the utility system “strength” at the point of interconnection, vs. the generating facility size. Stiffness ratio is a good proxy for assessing the voltage impact of a DER
facility.
CSR = 𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆𝑆 𝐶𝐶𝐶𝐶𝑆𝑆𝐶𝐶𝐶𝐶𝐶𝐶𝑆𝑆 𝑀𝑀𝑀𝑀𝑀𝑀 𝑎𝑎𝑆𝑆 𝐶𝐶𝑖𝑖𝑆𝑆𝑖𝑖𝑆𝑆𝐶𝐶𝑆𝑆𝑖𝑖𝑖𝑖𝑖𝑖𝐶𝐶𝑆𝑆𝐶𝐶𝑆𝑆𝑖𝑖𝐷𝐷𝐷𝐷𝐷𝐷 𝑠𝑠𝐶𝐶𝑠𝑠𝑖𝑖 𝐶𝐶𝑖𝑖 𝑀𝑀𝑀𝑀
CSR is evaluated at the interconnection, per site, and at the substation, for aggregate DER. For CSR ≥ 25 for both criteria, study proceeds as usual. CSR < 25 for either criteria initiates the “Advanced Study” phase.
“Advanced Study phase” of the System Impact Study (SIS) A more rigorous evaluation of harmonic impact of transformers, inverters;
also further evaluation of Rapid Voltage Changes and flicker. Allows the interconnection study to honor the “do no harm” intent.
Voltage Regulation & stand-alone solar facilities
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Voltage regulators are one key asset, amongst many, to maintaining proper voltage to all customers
Substation regulator (3 phase)
Distribution voltage regulators
Voltage Regulator Location Policy for stand-alone solar: background Voltage regulators are a key part of distribution system voltage
management Placement is determined in a distribution planning study, typically
performed every 5-7 years In the interim, the circuit “runs on autopilot” while circuit load data is
collected and monitored for load growth patterns This policy requires “stand-alone” DER facilities to locate “upstream” of
line voltage regulators Voltage regulators are critical asset in proper operation of Integrated
Volt/Var Control (IVVC) systems “Stand-alone” distributed generation facilities are not necessarily easily
adapted further out on distribution circuits, beyond line voltage regulators
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Review: Duke Energy ProgressDistribution System Demand Response (DSDR) project
A type of IVVC (Integrated Volt/Var management System), which provides peak demand reduction
Part of balanced solution to meet energy growth with energy efficiency
Approved Demand-Side Management/Energy Efficiency (DSM/EE) program in both NC and SC
Business case Defer two new combustion turbines (CT) Reduce emissions Displace more costly peak generation resources
Deployed on entire distribution grid Project initiated in 2008, fully operational in June 2014 A similar system remains a possibility in DEC; pilots
underway 31
DSDR Principles of Operation
ExistingFlattened Profile after feeder conditioning
Lower Regulatory Limit
Upper Regulatory Limit
• Flattened profile allows greater voltage reduction• Dynamically lower voltage to regulatory limit
o DMS network model used to maximize voltage reduction over timeo Each regulating zone and each phase is optimized independently
o Required adding a significant # of voltage regulators, with remote communications
Lower Voltage to Reduce MWs
Feed
er
Volta
ge
Feeder Distance
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DSDR – Realized Benefits
200+ MW of capacity, on average, during annual (summer & winter) peak condition activations Maximum capability of 316 MW during summer peak
Over 195,000 MWH of total energy savings through 2015 Validation of 178 MW of peak generation spinning reserves Validation of benefit from emergency voltage reduction activations Used successfully in 2014 & 2015 Polar Vortex events to manage winter
peak load
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Review: Circuit Stiffness and Voltage Regulator Policy
Duke is seeking to locate stand-alone solar facilities in a “smart” way Circuit Stiffness Review screen simply assures an adequate
evaluation of impacts Voltage regulator policy assures integrated operation of wide area
distribution system management technologies and stand-alone solar facilities
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In Conclusion
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Thank you Jason MartinDirector, [email protected] GajdaManager, DER Operations [email protected] FeltRenewable Strategy [email protected]
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