Key Concepts Of Distributed Generation

Transcription

1 Key Concepts Of Distributed Generation National Grid - April 29, 2015 International Association of Electrical Inspectors Western Massachusetts Chapter - Springfield MA Bob Moran, Jim Kehrer, Patti Cox, Lisa Jasinski

2 Key Concepts High Level Overview of Interconnection Process Activity Levels Third Party Ownership Compliance Documentation, AC Utility Disconnect Line Side Connections Resources and Contact Info 2

3 DG Activity Trends - NE 2,975 applications (140 MW )thru Q vs. 867 (65 MW) same period last year. (1300 in January 2015) Small (<100kW) applications may trigger large studies and costs cue to aggregate generation on circuit 3

4 Disclaimer DG is a broad subject, with each installation presenting a specific set of facts and issues Rules can and do change MA utilities have the same rules (except municipals) Anecdotes / specific cases will be difficult to discuss Relationship with stakeholders DG Seminar*** 4

5 1 - NO ADVERSE IMPACT No adverse impact on safety, reliability, or power quality Obligated to interconnect customers who meet the criteria per the Interconnection Tariff, relevant orders Interconnection Tariff (2006, 2009, 2012, 2014, 2015), Green Communities Act (2009), Net Metering Tariff (2009, 2012), MA D.P.U C, 11-11E MA D.P.U., R.I. P.U.C., New York P.S.C., FERC, ISO-NE 2015 Net Metering subsidy expected to approach $50M 5

6 2 - THIRD PARTY OWNERSHIP Host Customer (homeowner) responsible for the account Interconnecting Customer owns generating equipment ~ 80% of new applications are third party owned Financing for these systems varies widely Revenue from Renewable Energy Certificates 1 REC = 1 MWH generated by renewable energy Interconnecting Customer owns SRECs (Solar RECs) Massachusetts Clean Energy Center runs SREC auction 6

7 3 AC UTILITY DISCONNECT Accessible Lockable Visible break when open Interrupts the AC current of the system Shunt trips not allowed 7

8 4 COMPLIANCE DOCUMENTATION Agreements As-Built 1-line diagram Photos AC Utility Disconnect Placards, Labels, Access Commissioning Memo Witness Test Results Certificate of Completion 8

9 Simplified Application <=15kW Single Phase, <=25kW Three Phase Acknowledge Receipt of Application Acknowledge Application Complete Provide Conditional Approval Typically, no upgrades necessary Compliance Documentation (Pictures, labels) Change Standard Meter to Net Meter Provide Authority to Interconnect 9

10 COMPLIANCE DOCUMENTATION For Simplified Projects Application, HOST Customer Agreement, Signatures, Certificate of Completion Pictures of AC UTILITY DISCONNECT, inverter Customer-Owned Metering Labels, Placards 10

11 Customer Owned Metering Customers often install production meter to metering PV output (SRECs) Often looks very similar to company revenue meter Require labeling Customer Owned Production Meter Simplified, Expedited, or Standard 11

12 Expedited Projects ~ kW 12

13 190kW 13

14 Expedited Application >15kW Single Phase, >25kW Three Phase Acknowledge Receipt of Application Acknowledge Application Complete Provide Conditional Approval Often, no upgrades necessary Compliance Documentation (Pictures, labels) Phone line and insurance if >60 kw Change Standard Meter to Net Meter Provide Authority to Interconnect 14

15 COMPLIANCE DOCUMENTATION For Expedited Projects Interconnection Agreement, HOST Customer Agreement, As-Built 1-line, Commissioning Memo, Certificate of Completion Pictures of AC UTILITY DISCONNECT, inverters, service equipment Labels, Placards, Phone Line if >60kW Witness Test may be necessary Net Metering Allocation, Insurance 15

16 COMPLIANCE DOCUMENTATION For Expedited Projects Warning label at Point of Common Coupling (PCC) Directory identifying location of AC UTILITY DISCONNECT and SERVICE EQUIPMENT 16

17 Plaques Identifying Equipment Locations 17

18 Standard Application >500kW Pre-application required by tariff Screening, Impact Study, Conditional Approval Upgrades are always necessary primary metering, loadbreak, re-closer, line upgrades, $ubstation work Interconnection Service Agreement (documents necessary modifications, payments, schedule) Compliance Documentation (agreements, pictures, labels, insurance, as-built documents, witness test) Authority to Interconnect 18

19 1.5MW Wind Turbine 19

20 4.75MW Solar Site (18,000 panels) 20

21 Typical Utility Design >500kW 21

22 Typical Equipment Stand-Alone 22

23 AC UTILITY DISCONNECT for Standard Application >500 kw Accessible 24/7 by utility Lockable, tag-able Company has the legal right to operate and lock Customer-Owned Permanent Labeling May be multiple AC UTILITY DISCONNECTS on one site 23

24 COMPLIANCE DOCUMENTATION For Standard Projects Interconnection Agreement, HOST Customer Agreement, As-Built 1-line, Commissioning Memo, Certificate of Completion Pictures of AC UTILITY DISCONNECT, inverters, service equipment Placards, Phone Line, Insurance Witness Test, Recloser test Net Metering Allocation, Insurance 24

25 Plaques Identifying Equipment Locations 25

26 Witness Test / Relay Test 26

27 Communications Test For larger systems, we need visibility and control for our Dispatch Center Recloser and RTU communications tested and verified 27

28 Line Side Connections PV reduces load, so NEC allows for line side connection (ahead of over-current protection) Line Side Connections mean that PV output can be present with main breaker open AC Utility Disconnect becomes SERVICE MAIN DISCONNECT and must be SUITABLE FOR USE AS SERVICE EQUIPMENT May have External Disconnects that are SERVICE EQUIPMENT, and Internal Disconnects that are SERVICE EQUIPMENT Requires placards identifying location of each piece of SERVICE EQUIPMENT 28

29 Line Side Connection 29

30 Excerpts from ESB 750 Splices in meter socket prohibited Service Conductor Splicing - Service conductors may be spliced in accordance with the National Electrical Code (NEC) except for the following situations: above grade on Company pole unless in the supply space at transformer by Company within meter socket enclosure within conduits on pole inside of a building unless approved by the NEC. 30

31 Excerpts from ESB Taps Ahead of Main Service Equipment Any tap made ahead of the main service equipment for emergency systems, control power for circuit breaker, etc. shall be provided with disconnecting means and over-current protection adequate for the duty Such connections shall be made only where specifically accepted by the Company and approved by the NEC. 7.3 SELF-CONTAINED METER SOCKET INSTALLATIONS Meter socket troughs shall not be used as junction boxes or wiring troughs for splices or taps. 31

32 What Happens During An Outage? UL Listed inverters trip offline within 2 seconds, and remain offline for 5 min BUT - NOT ALL DG CONFIGURATIONS ARE UL LISTED Multiple inverters, multiple wind turbines, co-gen What could happen? If emergency generator is present, inverter could interpret that to mean utility is restored! If inverters generating, AND main breaker closed, inverters could back-feed crib, transformer, primary This would likely cause inverter to trip, but - BEWARE 32

33 Challenges High penetration of DG has potential for adverse impact Increasing complexity studies, operation, maintenance 33

34 Contact Info General DG-related inquiries can be ed to: Commercial DG-related billing inquiries can be ed to: Customer Service Work Request Group Demolition Requests / fax Phone numbers in ESB 750 Web Search National Grid Interconnection 34

35 Key Points To Remember No Adverse Impact AC Utility Disconnect Utility has legal right to operate Lockable, visible break when open Signage should provide direction Line Side Connections Power may be present even if main breaker is open Customer-Owned Metering Back-feed potential during outage 35

36 Recap Distributed Generation is a dynamic subject that presents many challenges - technical, operational, regulatory, strategy, financial, billing, customer service, etc. Each project involves a very specific set of facts and rules, and may involve multiple internal and external stakeholders Tariff timelines drive activity, and customer delays can add significant time to DG timeline All DG must be interconnected without adversely affecting safety, reliability, and power quality! 36