Scottish Affairs Committee - A Robust Grid for 21st Century ScotlandWritten evidence submitted by the National Grid

National Grid is pleased to input to the Scottish Affairs Committee inquiry into a Robust Grid for a 21st Century Scotland. Please note that we have limited our response to those areas which have a direct impact or relevance to National Grid’s role and operations.

About us

National Grid owns and operates the electricity transmission system in England and Wales and operates the system in Scotland, balancing supply and demand across Great Britain. In addition we manage the gas transmission system across Great Britain, and own regional gas distribution networks in England.

National Grid does not own any electricity transmission infrastructure in Scotland. Responsibility for transmission assets (ownership and investment) in Scotland is shared by SSE and SP Transmission.

In 2005, British Electricity Trading and Transmission Arrangements (BETTA) were introduced designating National Grid as the GB System Operator (GBSO). As part of this role we liaise very closely with the two Scottish Transmission Owners. We plan timescales to ensure that investment can be delivered in their transmission systems in terms of outages required on the system. We also plan operational timescales to allow them to manage and maintain their assets in line with the operational needs of the system. National Grid’s role has recently been extended to National Electricity Transmission System Operator (NETSO)—the operation of the new offshore transmission network in British territorial waters.

Security Standards and Network Design

The high voltage network in Scotland is in places designed to a different set of standards to those found broadly across England and Wales. This is due to the configuration of the electricity transmission network in Scotland, historical developments of the systems, and consideration of geographic coverage of demand over the Highlands and Islands.

In particular, a substantial part of SSE’s transmission system is operated at a lower voltage, 132kV, than is used in the vast majority of the SP and National Grid Electricity Transmission (NGET) systems. However, a common set of Security and Quality of Supply Standards (SQSS) apply to the systems. National Grid Electricity Transmission’s role as NETSO is to ensure that the offers we make to customers (as all agreements to use and connect to the transmission systems are with NGET as NETSO) comply with those standards.

Involvement with Regards to Investment Decisions Taken in Scotland

National Grid was part of the Electricity Networks Strategy Group,1 along with Scottish transmission owners. This group led by the UK Government and Ofgem created a vision for the electricity transmission system in Great Britain in 2020. Their initial report was published in 2009. An updated report which includes greater detail of upgrades to the Scottish transmission system is due to be published imminently.

In terms of National Grid’s input to investment decisions taken by the owners of the Scottish transmission assets, broadly these are limited to discussions regarding resilience plans and customer connections. However, we do also work with the Scottish transmission owners to develop consistent generation and demand background scenarios. While these consistent datasets are available, ultimately it is for the Scottish transmission owners to justify their investment plans and the basis on which these investments are made to Ofgem.

Assuming the Scottish transmission owners plans reflect compliance with the SQSS, the major impact on the NETSO of Scottish Transmission investment is in making sure that major projects are completed in a timely manner. Where there is insufficient transmission system capacity, National Grid as operator of the system can sometimes be forced to constrain off generation in order to balance the system, incurring significant costs on behalf of consumers. Where delivery of investments to relieve these constraints are delayed, the high levels of constraint costs can be prolonged.

I very much hope that the information provided is helpful, please do not hesitate to contact us for further information on any of the points raised.

2 February 2012