North of England boundaries

The North of England transmission region includes the transmission network between the Scottish border and the north Midlands.

This includes the upper north boundaries B7a and B8. The figure below shows likely power flow directions at system winter peak.

The figure below shows the general pattern of power flow directions expected to occur most of the time in the years to come up to 2031, i.e. power will generally flow from north to south. The arrows in the diagram illustrate power flow directions and are approximately scaled relative to the winter peak flows.

The arrows in the diagram illustrate power flow directions and are approximately scaled relative to the winter peak flows.

Regional drivers

The connection of large amounts of new generation, most of which is intermittent renewables, in Scotland and the north will cause overloading in the northern transmission network unless appropriate reinforcements are in place. Future power transfer requirements could be more than double compared to what they are today in some scenarios.

All four scenarios suggest growth in low-carbon and renewable generation, in addition to new storage and interconnector developments. The connected fossil fuel generation could see sustained decline in all but the Steady Progression scenario., but would not be phased out in the region until at least 2040. Presently, most of the northern transmission network is oriented for north-south power flows with connections for demand and generation along the way.

At times of high wind generation, the power flow will mostly be from north to south, with power coming from both internal boundary generation and generation further north in Scotland.

When most of this area and Scotland is generating power, the transmission network can be highly overloaded. The loss of one of the north-to-south routes can have a highly undesirable impact on the remaining circuits.

As the potential future requirement to transfer more power from Scotland to England increases, B7a is likely to reach its capability limit and needs network reinforcement. The potential future restrictions to be overcome across B7a are summarised:

  • At high power transfer, thermal limitations occur on a number of circuits within the north east 275kV ring.

  • Limitation on power transfer from Cumbria to Lancashire (boundary B7a) occurs due to thermal limitation at Padiham–Penwortham circuit.

The need for network reinforcement to address the abovementioned potential capability issues will be evaluated in the NOA 2021/22 CBA.

Gross demand in the North of England in expected to increase to a total of up to 11GW by 2030, generation in the region is already double that figure today, and will increase by an additional 5GW by 2020. The North of England is a heavily power-exporting region and must also manage power flows from Scotland to the demand centres in the Midlands and South.

All four scenarios show a steady increase in the gross demand of the region that is outstrips the increase in local generation for all but the Leading the Way scenario. There are stark differences seen in the range of local generation under the four scenarios, from 5 – 10 GW is expected by 2050, up from 2.8GW today. More local generation will mean that less of the North-South power flows that travel through this region will be absorbed by demand.

The highly variable nature of power flows in the north presents challenges for voltage management, and therefore automatic reactive power control switching is utilised. This helps to manage the significant voltage drop due to reactive power demands which arise at times of high levels of power flow on long circuits.

Operational reactive switching solutions are also used to manage light loading conditions when the voltage can rise to unacceptable levels. The high concentration of large conventional generators around Humber and South Yorkshire means that system configuration can be limited by high fault levels. Therefore, some potential network capability restrictions in the north can be due to the inability to configure the network as desired due to fault level concerns.

The need for network reinforcement to address the abovementioned potential capability issues will be evaluated in the NOA 2021/22 CBA.

Boundary regions

Click on the regions below to expand the boundary and understand its capability and challenges.

Interpreting boundary graphs

The graphs show a distribution of power flows for each of our Future Energy Scenarios, in addition to the boundary power transfer capability and NETS SQSS requirements for the next twenty years. ​

Each scenario has different generation and demand so produces different boundary power flow expectations. From applying the methodology in the NETS SQSS for wider boundary planning requirements (as discussed in chapter 2), we determine for each scenario:

  • The economy criteria - solid coloured line

  • Security criteria - dashed coloured line

  • Current boundary capability – solid black line

Due to the NOA being published after the ETYS, the boundary capability line (red line) is prepared from the 2020/21 (previous year’s) NOA optimal path released in January 2021 which uses the 2020/21 FES and ETYS data. This is the best information available at the time of publication and will change annually and over time as the network, generation, demand and more importantly the NOA optimal path changes. More information about the NOA methodology can be found here. The 50%, 90%, Economy RT and Security RT are calculated from the 2021/22 FES and ETYS processes. Where the NOA transfer capability is not available, there is a black line that provides the current ETYS 2021/22 transfer capability​.

Note: Boundary capability line is affected by the generation and demand profiles within each FES background. Therefore, the graphs are provided for indicative purposes only and cannot be directly compared. ​

The calculations of the annual boundary flow are based on unconstrained market operation, meaning network restrictions are not applied. This way, the minimum cost generation output profile can be found. We can see where the expected future growing needs could be by looking at the power flows in comparison with boundary capability.​

On each graph, the two shaded areas provide confidence as to what the power flows would be across each boundary:

  • The darker region shows 50% of the annual power flows

  • The lighter region shows 90% of the annual power flows​

From the regions, we can show how often the power flows expected in the region split by the boundary are within its capability (red line). If the capability of the boundary is lower than the two regions over the next 20 years, there might be a need for reinforcements to increase the capability. However, if the line is above the shaded regions, it shows that there should be sufficient capability here and that potentially no reinforcements are needed from a free market power flow perspective until the shaded regions exceed the capability (red line).

Boundary B7a – Upper North of England

Boundary B7a bisects England south of Teesside and into the Mersey Ring area. It is used to capture network restrictions on the circuits feeding down through Liverpool, Manchester and Leeds.​

Boundary flows and base capability

 

The capability line (in red) is based on the recommendations from the NOA 2020/21 optimal path which uses the 2020/21 FES and ETYS data as inputs. The 50%, 90% Economy RT and Security RT lines are based on FES 2021/22.

The current boundary capacity is limited to 9.43GW due to a thermal constraint on the Offerton - West Boldon 275kV circuit.

For all scenarios in the FES, the SQSS economy required transfer and expected power flows quickly grow to beyond the present boundary capability. This suggests a strong need for network development to manage the increasing power flows.​

The FES show a lot of intermittent renewable generation in the north, meaning the spread of boundary power flows is very wide. With low northern generation output in it is credible to have power flowing from south to north feeding northern demand. ​

The magnitude of the south to north power flows is low compared to those in the opposite direction so network capability should be sufficient to support those conditions.​

Boundary B8 – North of England to Midlands

Boundary B8 is one of the wider boundaries that intersects the centre of GB, separating the northern generation zones including Scotland, Northern England and North Wales from the Midlands and southern demand centres.​

Boundary flows and base capability

 

The capability line (in red) is based on the recommendations from the NOA 2020/21 optimal path which uses the 2020/21 FES and ETYS data as inputs. The 50%, 90% Economy RT and Security RT lines are based on FES 2021/22.

The current boundary capacity is limited to 11.4GW due to a thermal constraint on the Cellerhead - Drakelowe 400kV circuit.

For all scenarios in the FES, the SQSS economy required transfer and expected power flows quickly grow to beyond the present boundary capability. This suggests a strong need for network development to manage the increasing power flows.​

The FES show a lot of intermittent renewable generation in the north, meaning the spread of boundary power flows is very wide. With low northern generation output in it is credible to have power flowing from south to north feeding northern demand. ​

The magnitude of the south to north power flows is low compared to those in the opposite direction so network capability should be sufficient to support those conditions.​