INDEPENDENT POWER 2001 SALES

1
Massachusetts DTE DG Interconnection
Collaborative DG Cluster Proposal November
12, 2002
2
What Is An Interconnect (Nomenclature)?

• Basically, the interface between Distributed
  Generation (DG) equipment and the grid, called
  the Area Electrical Power System (EPS)

Point of Common Coupling (PCC)
Radial
EPS
Customer Facility
Network
Load 3
Load 2
Load 1
DG
3
DG Cluster Proposal Overview

• Standardized Process and Requirements
• Ensure safety and reliability
• Follows national standards
• Equipment must be certified or undergoes design
  review
• For small generation lt20MW
• Differentiating By
• One of three generator size thresholds
• Potential impact of generator on Electric Power
  System (EPS)
• Type of EPS at Point Of Common Coupling (PCC)

4
Process Overview
Generator Application
gt20MW?
Yes

• Scope of process shrinks considerably when
  expedited
• Defines screens for certified equipment

gt2MW?
Historic Application Process
Yes
Meets Screens?
Expedited Application Process
Yes
Super Expedited Application Process
Interconnect Agreement
5
Size Threshold Categories

• Less than 10kW
• Accepts utility proposal
• Three page application/agreement
• No review/payments necessary
• Less than 2 MW eligible for super-expedited
  process
• Certified equipment
• De minimis grid impact
• No connection to transmission lines
• 2-20MW eligible for expedited process
• Check for distribution and transmission impact

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10 kW To 2 MW

• Units certified by UL or other NRTL against
  UL1741 (representing IEEE Std1547 Draft 10)
• 2 screens for determination of no grid impact
• Primary screen conservative, utility origin
• 100 of units that pass are OK
• Secondary screen - less conservative
• 80-99 of units are OK?
• Creates presumption of acceptance

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Certification

• Verifies that equipment is designed to ensure
  electrical protection safety
• Website registry
• UL or similar NRTL describes equipment package
  and test results
• Posted w/ 6 week comment period
• UL responds to any comments
• Once certified -- no type testing and no other
  equipment can be required
• Already UL-approved equipment is grandfathered

8
IEEE Std1547

• Overview
• References
• Definitions and Acronymns
• Technical Specs and Requirements
• General Requirements
• Response to Area EPS Abnormal Conditions
• Power Quality
• Islanding
• Test Specifications and Requirements
• Interconnection Test
• Production Tests
• Interconnection Installation Evaluation
• Commissioning Tests
• Periodic Interconnection Tests

• Annexes (Informative)
• Flicker Information
• Interconnection Tests
• Commissioning Tests
• Bibliography

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Overall Super-ExpeditedProcess Flow
SG Submits Complete Application
IP Conducts Initial Review
To Expedited Process
Passes Primary Screens?
Passes Secondary Screens?
IP Conducts Supplemental Review (If SG Agrees)
Meeting To Discuss Initial Review
No
No
No
Yes
Yes
SG Initiates
If Needed, IP SG Agree To Mods?
IP Conducts Limited IC Review
Technical Dispute Resolution
Yes
If Needed, IP SG Agree To Minor Mods?
No (IP Initiates)
Interconnect Agreement
Yes
Note SG is Small Generator IP is
Interconnection Provider
10
Basis For Screens

• Circuit size versus DG size
• DG contribution to fault
• Short circuit interrupting capability limit
• Three-wire and four-wire circuit criteria
• Nameplate limits

• Circuit impact
• Fault handling, fuse desensitizing nuisance
  trip
• Short circuit handling
• Proper connection
• Single phase imbalance

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Screens Primary

• Aggregate DG capacity limited to a low percentage
  of the peak load of a distribution circuit
  (different limits for radial vs spot network vs
  secondary grid network)
• DG contribution to circuit fault current is
  limited
• DG not allowed to cause grid protective devices
  to exceed 90 of their short circuit interrupting
  capability
• In aggregate, DG cannot be gt 10MW where transient
  stability limits posted
• Interconnection configuration-specific limits on
  single-phase generator hookup and capacity to
  avoid imbalance, overload, and possible
  neutral/grounding problems

12
Screens Secondary

• Aggregate DG capacity limited to a higher
  percentage of the peak load of the distribution
  circuit
• Basically the same limits on fault current
  contribution and short circuit interrupting
  impact as primary screen

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10kW-2MW Costs

• Application fee
• Additional surcharge for interconnection review
• Limited to reasonable amounts based on size
• No other costs for interconnection under Super
  Expedited procedures

14
Dispute Resolution

• Elements
• Technical Master
• Hotline
• ADR for non-technical disputes
• IP must initiate if SG Applicant clears secondary
  screen
• Gen Applicant has burden if both screens failed

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Metering

• Only metering required for this agreement is that
  necessary to implement the interconnection

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Timing

• 10 days to review application
• 15 days to review screens
• 5 days to execute IA (Interconnect Agreement)
• If Primary Screen failed
• 10 days for additional review (after surcharge is
  paid)
• 5 days to notify applicant of results
• 5 days to send IA

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Interconnection Agreement

• Standard form Agreement
• Shorter form for generators lt2MW
• Can be pre-executed

18
Interconnection Application

• Standard form
• Shorter Form for generators lt2MW

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2-20MW Interconnection

• Includes transmission impact issues
• Direct transmission interconnection as well as
  distribution
• Used by all generator sizes for which lt2MW
  procedures do not apply

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Basic Process

• Optional scoping meeting up front
• Three main components
• Feasibility study
• Impact study (if needed)
• Facilities study (if needed)
• Patterned after Utility proposal

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Feasibility Study

• Checks to see if generator has an impact
  distribution or transmission system
• load flow (unless no export)
• short circuit
• grounding
• IP shall rely to extent practical on existing
  studies
• Gives generator developer idea of interconnection
  costs

22
Transmission Impact Study

• Only undertaken if Feasibility Study raises
  questions of transmission impacts
• Usually costly -- to be avoided if possible
• If no impact study needed - generator drops from
  queue

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Distribution Impact Study

• Purpose
• Identify generator design elements that protect
  distribution system
• Assess impact of generator on distribution
• No design review needed if
• Certified
• Generator meets criteria similar to 0-2MW
  secondary screens (without secondary network
  items)
• Includes
• Distribution load flow study
• Equipment interrupt rating analysis
• Protection coordination study
• System operation impact analysis

24
Facilities Study

• Identifies attachment facilities needed for
  interconnection including distribution system
  upgrades
• If no facilities needed (customer sited
  generation), no study undertaken

25
2-20MW Costs

• To be discussed
• Limit interconnection costs to only those
  directly related to the application

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Transmission Queue

• To be discussed
• FERC is scheduling a conference and possible NOPR
  on the subject

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Interconnection Agreement/Application

• Forms to be developed

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Massachusetts DTE DG Interconnection
Collaborative Background
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IEEE Std 1547 General Requirements Summary

• Voltage regulation inside ANSI C84.1 Range A
• Grounding coordinated with Area EPS
• Synchronize without voltage fluctuation at PCC
  gt5 of prevailing voltages
• Networks

• Spot networks only for now

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1547 General Requirements Summary (Continued)

• DG shall not energize EPS when EPS is
  de-energized
• DG gt 250kVA (unit or aggregate at PCC) shall have
  provisions for monitoring DG status, real power,
  reactive power
• When required by EPS, accessible, lockable,
  visible-break isolation device (switch) located
  between DG and EPS

Isolation Switch Suitable for 70kW DG
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1547 Abnormal Conditions Response Summary

• Voltages outside of table below shall cause DG to
  cease to energize within clearing time
• Detected at PCC or point of DG connection if
• Aggregate DG capacity lt 30kW
• Interconnect equipment certified to pass
  non-islanding test
• Aggregate DG capacity lt 50 total local EPS
  demand AND export of power prohibited

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1547 Abnormal Conditions Response Summary
(Continued)

• DG lt 30 kW, frequencies shall fall in range of
  59.3 to 60.5 Hz else cease to energize within
  0.16 seconds
• DG gt 30 kW
• cease to energize within 0.16 seconds if gt60.5 Hz
• cease to energize within an adjustable time delay
  if undervoltage in range of 59.8 to 57 Hz
• cease to energize within 0.16 seconds if lt57.0 Hz
• After a disturbance, DG reconnect only if voltage
  and frequency within range
• Interconnection equipment shall be designed to
  coordinate with EPS reclosing practices and
  include ability to delay reconnect up to 5 minutes

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Power Quality Summary

• DG connected to single phase distribution shall
  not inject DC current gt0.5 DG full rating
• The DG shall not create objectionable flicker
  for other customers on the area EPS
• DG harmonic injection shall not exceed

Maximum Harmonic Current Distortion ( of current)
Harmonic Order (h) hlt11 11lthlt17 17lthlt23
17lthlt23 35lth Percent () 4.0 2.0 1.5 0.6 0.3
Current Distortion
Total Demand Distortion Maximum 5.0
Harmonic
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Testing Requirements Summary

• Five kinds of test are defined
• Design test certifies that interconnection
  equipment meets the standard requirements
• Production test factory test of DGs
  conformance to voltage and frequency variation
  limits
• Interconnection installation evaluation
  basically a verification that the DG and
  interconnection design meet the standard
• Commissioning test conducted at the facility to
  verify adjustable settings are correct and
  protective functions are operating properly
• Periodic interconnection tests A periodic test
  of the interconnect protection system

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Screens Primary

• lt5 of annual peak load on radial circuits
• lt5 of peak load (or 50kW max) on spot networks
  (inverters only)
• Secondary grid distribution networks
• induction generator or inverter
• not exceeding 50 of facility minimum load
• lt10 contribution to circuit max fault current
• Not cause grid protective devices to exceed 90
  of their short circuit interrupting capability
• In aggregate, cannot be gt10MW where transient
  stability limits posted
• Phase imbalance limits if single-phase and
  connected to center tap neutral of a 240V service
• lt20kVA if single-phase and on a shared secondary
• Single-phase connection requirements
• lt10 of line capacity if single phase and section
  configuration is three-phase, 4-wire or a mix

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Screens Secondary

• Radial circuits lt15 of line section design
  capacity
• Spot networks lt5 of peak load on spot networks
• Secondary grid networks
• On any network, use reverse power protection
  except
• if generator lt50 of min facility load or 500kW
• Basically same limits on fault current
  contribution and short circuit interrupting
  impact as primary screen