“Transmission or Distribution”

Phil Collins

March 18, 2005

CUSC Principles of Ownership

• Power Station• Busbar clamp on busbar side of busbar isolators on generators circuit

• Distribution System• Busbar clamp on busbar side of busbar selector isolator on distribution

circuit• If no busbar exists, an equivalent isolator• If no isolator exists, an agreed bolted connection at or adjacent to the tee

point

• Non-Embedded Customer• Clamp on circuit breaker side of cable disconnections at User’s substation

Overview

• Transmission Connection Boundary Definition:• Shareable or potentially shareable assets classed as Infrastructure• Substations and associated site infrastructure and land classed as

Transmission Infrastructure• Generation only Spurs are Transmission Infrastructure• Shared substations where National Grid or TOs own the busbars and

transformer circuits connecting shared LV substations are Infrastructure

• Grid Supply Points• DNO has no right of export

• Embedded Connections• Non Contiguous Connections

Transmission Connection Examples

Distributor Owned Substation

TO Owned Substation132kV, 275kV or 400kV

TOSubstation

TOSubstation

ConnectionBoundary

Demand

Infrastructure Assets

Single DNO T Connection

LVTO Owned Substation

TO Owned Substation132kV, 275kV or 400kV

TOSubstation

User Owned AssetsInfrastructure

Assets

TOSubstation

~

Single T Connection

Shared LVTO Owned Substation

TO Owned Substation132kV, 275kV or 400kV

TOSubstation

User Owned Assets

Demand

Infrastructure Assets

TOSubstation

~

Shared T Connection

Distributor OwnedSubstation

TO Owned Substation132kV, 275kV or 400kV

TOSubstation

ConnectionBoundary

Demand

~Infrastructure

Assets

TOSubstation

Generation and Demand Connection

User Owned Assets

TO Owned Substation132kV, 275kV or 400kV

Generation Only - Non Spur Connection

TOSubstation

Infrastructure Assets

GeneratorAssets

~

Infrastructure AssetsTO

Substation

~

TO Owned Substation132kV, 275kV or 400kV

Generation Only Spur (Turn in)

InfrastructureAssetsGenerator

Assets

~

TO Owned Substation132kV, 275kV or 400kV

Generation Only Spur (Remote sub)

GeneratorAssets

~

TOSubstation

InfrastructureAssets

TO Owned Substation132kV, 275kV or 400kV

Generation Only Spur (Tee)

GeneratorAssets

~Infrastructure

Assets

Distribution Connection Examples

Distributor Owned Substation

National Grid Substation132kV, 275kV or 400kV

TOSubstation

TOSubstation

DNO ConnectionBoundary

Demand

Infrastructure Assets

DNO Connection with embedded generationand demand

~

Distributor Owned Substation

Demand

DNO Connection with embedded generationand demand

~

National Grid Substation132kV, 275kV or 400kV

Distributor Owned Substation

DNO ConnectionBoundary

Distributor Owned Substation

Demand

DNO Connection with embedded generationand demand

~

National Grid Substation132kV, 275kV or 400kV

Distributor Owned Substation

DNO ConnectionBoundary

Connection Example

Distributor Owned Substation

TO Owned Substation132kV, 275kV or 400kV

TOSubstation

TOSubstation

ConnectionBoundary

Infrastructure Assets

What am I?What am I?

~

No Demand

Generator

Application Process - Transmission

Transmission Application ProcessApplications

Customer NGC (GBSO) Host TO

Affected TO

Transmission Application ProcessOffers

Host TO

Affected TO

CustomerGBSO

Transmission Application ProcessOffer Acceptance

Customer

Host TO

GBSO

Affected TOs

Transmission Application ProcessSummary

• User makes application

• GBSO makes an NGC Construction Application if required

• TO make TO Construction Offer (TOCO) if works are required

• GBSO makes Offer to Customer

• Customer signs and returns Offer

• GBSO signs Offer and TOCO

• GBSO returns TO Construction Agreement

Application Process - Embedded

Embedded Application ProcessSummary

Embedded Generator NGC (GBSO) Host TO

Affected TODNO

Embedded Application ProcessKey Attributes

• BEGA• User Applies• NGC Construction Application• TO Construction Offer (null)• BEGA Gets Construction Agreement and Bilateral Agreement• NGC makes Mod Notice to DNO (possible CONSAG)

• BELLA• User and DNO Applies• NGC Construction Application• TO Construction Offer (null)• BELLA gets Bilateral Agreement and DNO gets Construction Agreement