Greater London IRRP - Backgrounder
About Greater London
The Integrated Regional Resource Plan
(“IRRP”) for the Greater London subregion addresses the electricity needs for
the area over the next 20 years from 20152034. Greater London is a sub-region of
the London Area planning region and
roughly encompasses the City of London
and parts of Middlesex County.
Electrical supply to the sub-region is
provided by six transformer stations (TS)
shown in the figure. In the August 2015
Scoping Assessment report for the London
Area region, a need for capacity and to
meet restoration timelines was identified
in the Greater London sub-region. The
Greater London Sub-region Planning Area
demand growth forecasted for the
Clarke, Talbot and Wonderland stations was expected to exceed the capacity of each station
within the 20-year study horizon. Load supplied from two stations, Clarke and Talbot, was
identified as being at risk for not meeting restoration levels as defined in IESO’s reliability
standards.
The Nelson TS is a major station supplying the City of London’s downtown. Prior to the
initiation of the regional planning process for this area, plans for reconfiguration of Nelson TS
were underway by London Hydro and Hydro One. The station reconfiguration entails
replacing the current 115/13.8 kV stepdown station with a new 115/27.6 kV stepdown station
and rebuilding the downtown distribution network at 27.6 kV, which are both expected to be
completed for a 2019 in-service date. The reconfiguration project will allow the integration of
the London downtown distribution system with the surrounding 27.6 kV network, allowing
flexibility with operations and providing backup capability to the critical downtown load. With
the new Nelson TS operating in 2019, London Hydro will be able to balance load across its
entire service territory, eliminating the station capacity needs previously identified in the Need
Screening and Scoping Assessment reports for the London Area Region.
The Greater London IRRP was developed by a Working Group composed of the Independent
Electricity System Operator (IESO), London Hydro, and Hydro One Networks Inc.
Recommendations in the IRRP
The implementation of provincial conservation targets established in the 2013 Long‐Term
Energy Plan (LTEP) is important for managing demand in Ontario. Local peak‐demand impacts
associated with the provincial conservation targets were assumed before identifying residual
needs, consistent with the Conservation First Framework.
In addition to the recommended actions outlined in the table below, provincial programs that
encourage the development of distributed generation also contribute to reducing peak demand
in the sub-region. The Local Distribution Companies (LDCs) and the IESO will continue their
activities to support these initiatives and monitor their impacts.
Restoration Needs
Recommendations

Load supplied from two stations,
Clarke TS and Talbot TS, has been
identified as being at risk for not
meeting IESO’s load restoration
timelines in the event of a double
element outage



Optimize the distribution system to achieve the
maximum transfer capability.
Install automated switching on existing
distribution system.
Extend existing feeders to increase distribution
transfer capability.
Continue to monitor Clarke TS and Talbot TS
feeder limits and area load growth.
Based on the electrical demand forecasts provided by London Hydro and Hydro One
Distribution, the supply capacity for the Greater London sub-region is sufficient until the end of
the 2034 study period. The recommended near-term plan is able to substantially address the
restoration needs in the sub-region.
Due to the inherent uncertainty associated with producing long-term load forecasts, there is
potential that additional load could materialize within the Greater London sub-region within
the study period. The Working Group will work with the local communities to monitor leading
indicators for growth in the sub-region. This includes monitoring changes to growth targets,
the composition and location of residential, commercial and industrial customer segments, and
the effects on electricity demand related to the implementation of community energy plans
and/or provincial energy policy documents. If these or other factors impact service reliability or
capacity of the local electricity delivery systems, a new IRRP process may be initiated ahead of
the 5-year planning cycle.
Community Engagement
Ensuring that communities are kept up-to-date on regional electricity planning is important.
The Greater London Working Group met with the City of London to share the needs that were
identified during the regional planning process, and the immediate actions being undertaken by
the IESO, Hydro One Networks and London Hydro to ensure a reliable and economic level of
local service is maintained. The meeting also provided an opportunity to begin discussions on
planning for the longer-term. While no longer-term needs have been identified for this area
during the 20-year planning cycle, discussions that take place now as part of community energy
planning and municipal sustainability initiatives will help to inform future electricity plans and
alignment of these processes.
The IESO remains open to additional meetings and discussions with municipalities and
communities to support further engagement of the Greater London IRRP.
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About Regional Planning in Ontario
 Regional planning is a process for identifying and meeting local electricity needs and
typically focuses on 230 kV and 115kV infrastructure. The objective is to maintain a reliable
and cost‐effective electricity supply to customers. The IRRP process is an integrated
approach, which looks at conservation, generation, wires, demand management and other
innovative solutions for the near, medium and long term.
 Regional planning is part of the broader electricity system planning process, which includes
the Long‐Term Energy Plan which sets the policy framework and targets for resource
procurement, bulk system planning which focuses on 230 kV and 500kv transmission lines,
and distribution system planning.
 Developments over the past few years have changed how regional planning is done. In
2010, the OEB announced an initiative to develop a Renewed Regulatory Framework for
Electricity, which concluded that a structured approach to regional planning was needed. In
2013, the Ontario Energy Board formalized the regional planning process.
o Through this process, either Hydro One or the transmitter determines if there are
regional electricity needs that require regional coordination. If yes, then the IESO
determines which type of study is required. If a more comprehensive study, beyond
a simple “wires” (transmission and/or distribution) solution, is required, then the
IESO leads the development of an IRRP examining conservation, generation and
wires solutions.
 The IRRP addresses electricity needs over a 20-year period:
o It identifies investments for immediate implementation to meet near‐term needs,
with consideration given to their lead times for development.
o
The IRRP also identifies approaches to meeting potential medium‐ and long‐term
needs, but given forecast uncertainty, it maintains flexibility for medium- and long‐
term options and does not commit to specific projects at this time.
Key Resources
London Area planning web page: www.ieso.ca/London-Area
About the regional planning process: www.ieso.ca/regional-planning
Inquiries about the Greater London IRRP: [email protected]