Grid

Constraints

System

What stops electricity reaching demand, and what was done about it?

Published transmission constraint activity, its volume and cost.

NESO financial year 2026/27 (from 1 Apr 2026).

NESO's measured breakdown is published on a delay. The latest settlement date in the file is 2026-10-11.

Constraint cost

Cost of actions NESO took to manage transmission constraints, in £. Source: NESO (constraints).

Revisions shown.

Cost, £ million

  • Reducing largest loss
  • Increasing system inertia
  • Voltage constraints
  • Thermal constraints

Constraint volume

Energy volume of those actions, MWh.

Volume, GWh

  • Reducing largest loss
  • Increasing system inertia
  • Voltage constraints
  • Thermal constraints

Settlement date 2026-10-11

Swipe for more columns

Category£MWhShare of £
Reducing largest loss000%
Increasing system inertia968,37713,92837%
Voltage constraints961,80617,79137%
Thermal constraints663,813-3,55726%
Total2,593,99628,162100%

Boundary flow and limit (forecast)

NESO's day-ahead snapshot.

Day-ahead forecast, issued Fri 23 Oct 2026, 15:28 BST

No national cost is allocated to a boundary unless the file carries that allocation.

No boundary map is drawn. The file names constraint groups and does not carry coordinates.

BOLSELEX12026-10-24 23:30Limit 10,000 MWFlow 533 MW
TimeLimit MWFlow MW
00:0010,000573
00:3010,000633
01:0010,000672
01:3010,000656
02:0010,000660
02:3010,000699
03:0010,000761
03:3010,000803
04:0010,000829
04:3010,000845
05:0010,0002,536
05:3010,0002,238
06:0010,0002,243
06:3010,0002,187
07:0010,0002,695
07:3010,0003,262
08:0010,0003,081
08:3010,0002,989
09:0010,0003,026
09:3010,0003,078
10:0010,0003,068
10:3010,0003,160
11:0010,0002,853
11:3010,0002,437
12:0010,0002,403
12:3010,0002,450
13:0010,0002,389
13:3010,0002,274
14:0010,0002,175
14:3010,0002,117
15:0010,0001,578
15:3010,000956
16:0010,0001,027
16:3010,0001,129
17:0010,000793
17:3010,000389
18:0010,000497
18:3010,000631
19:0010,0001,020
19:3010,0001,422
20:0010,0001,117
20:3010,000797
21:0010,000309
21:3010,000-167
22:0010,000-636
22:3010,000-1,158
23:0010,000530
23:3010,000533
CANDUNEX2026-10-24 23:30Limit 10,000 MWFlow 805 MW
TimeLimit MWFlow MW
00:0010,000845
00:3010,000857
01:0010,000857
01:3010,000859
02:0010,000859
02:3010,000858
03:0010,000859
03:3010,000860
04:0010,000861
04:3010,000860
05:0010,0002,660
05:3010,0002,385
06:0010,0002,428
06:3010,0002,449
07:0010,0003,023
07:3010,0003,607
08:0010,0003,427
08:3010,0003,385
09:0010,0003,479
09:3010,0003,608
10:0010,0003,588
10:3010,0003,582
11:0010,0003,177
11:3010,0002,758
12:0010,0002,757
12:3010,0002,767
13:0010,0002,696
13:3010,0002,614
14:0010,0002,553
14:3010,0002,461
15:0010,0001,888
15:3010,0001,298
16:0010,0001,393
16:3010,0001,483
17:0010,0001,137
17:3010,000778
18:0010,000935
18:3010,0001,106
19:0010,0001,488
19:3010,0001,867
20:0010,0001,522
20:3010,0001,185
21:0010,000670
21:3010,000144
22:0010,000-365
22:3010,000-878
23:0010,000809
23:3010,000805
CANSELEX2026-10-24 23:30Limit 10,000 MWFlow 825 MW
TimeLimit MWFlow MW
00:0010,000865
00:3010,000877
01:0010,000877
01:3010,000879
02:0010,000879
02:3010,000878
03:0010,000879
03:3010,000880
04:0010,000881
04:3010,000880
05:0010,0002,680
05:3010,0002,405
06:0010,0002,448
06:3010,0002,469
07:0010,0003,043
07:3010,0003,627
08:0010,0003,447
08:3010,0003,405
09:0010,0003,499
09:3010,0003,628
10:0010,0003,608
10:3010,0003,602
11:0010,0003,197
11:3010,0002,778
12:0010,0002,777
12:3010,0002,787
13:0010,0002,716
13:3010,0002,634
14:0010,0002,573
14:3010,0002,481
15:0010,0001,908
15:3010,0001,318
16:0010,0001,414
16:3010,0001,503
17:0010,0001,157
17:3010,000798
18:0010,000955
18:3010,0001,126
19:0010,0001,508
19:3010,0001,887
20:0010,0001,542
20:3010,0001,205
21:0010,000690
21:3010,000164
22:0010,000-345
22:3010,000-858
23:0010,000829
23:3010,000825
DRESHEX12026-10-24 23:30Limit 6,000 MWFlow 3,477 MW
TimeLimit MWFlow MW
00:006,5002,766
00:306,5002,961
01:006,5003,120
01:306,5003,278
02:006,5003,338
02:306,5003,419
03:006,5003,436
03:306,5003,455
04:006,5003,499
04:306,5003,502
05:006,0003,484
05:306,0003,469
06:006,0003,423
06:306,0003,388
07:006,0003,332
07:306,0003,248
08:006,0003,213
08:306,0003,146
09:006,0003,188
09:306,0003,214
10:006,0003,254
10:306,0003,416
11:006,0003,432
11:306,0003,496
12:006,0003,593
12:306,0003,605
13:006,0003,508
13:306,0003,515
14:006,0003,386
14:306,0003,502
15:006,0003,530
15:306,0003,520
16:006,0003,508
16:306,0003,442
17:006,0003,311
17:306,0003,104
18:006,0002,859
18:306,0002,628
19:006,0002,577
19:306,0002,648
20:006,0002,728
20:306,0002,834
21:006,0003,041
21:306,0003,348
22:006,0003,510
22:306,0003,533
23:006,0003,518
23:306,0003,477
DUNSELEX2026-10-24 23:30Limit 10,000 MWFlow -24 MW
TimeLimit MWFlow MW
00:0010,000-30
00:3010,000-25
01:0010,000-25
01:3010,000-24
02:0010,000-24
02:3010,000-25
03:0010,000-25
03:3010,000-25
04:0010,000-25
04:3010,000-26
05:0010,000806
05:3010,000519
06:0010,000583
06:3010,000648
07:0010,0001,255
07:3010,0001,857
08:0010,0001,686
08:3010,0001,673
09:0010,0001,812
09:3010,0001,957
10:0010,0001,963
10:3010,0001,964
11:0010,0001,534
11:3010,0001,110
12:0010,0001,095
12:3010,0001,076
13:0010,0001,034
13:3010,000998
14:0010,000883
14:3010,000764
15:0010,000549
15:3010,000337
16:0010,000574
16:3010,000812
17:0010,000281
17:3010,000-257
18:0010,000-187
18:3010,000-108
19:0010,000120
19:3010,000343
20:0010,000-25
20:3010,000-390
21:0010,000-688
21:3010,000-992
22:0010,000-1,239
22:3010,000-1,487
23:0010,000-25
23:3010,000-24
ESTEX2026-10-24 23:30Limit 10,000 MWFlow 800 MW
TimeLimit MWFlow MW
00:0010,000835
00:3010,000852
01:0010,000852
01:3010,000854
02:0010,000854
02:3010,000853
03:0010,000854
03:3010,000855
04:0010,000856
04:3010,000855
05:0010,0003,625
05:3010,0003,350
06:0010,0003,393
06:3010,0003,414
07:0010,0003,980
07:3010,0004,554
08:0010,0004,393
08:3010,0004,350
09:0010,0004,420
09:3010,0004,551
10:0010,0004,534
10:3010,0004,530
11:0010,0004,125
11:3010,0003,709
12:0010,0003,710
12:3010,0003,719
13:0010,0003,646
13:3010,0003,562
14:0010,0003,408
14:3010,0003,260
15:0010,0002,438
15:3010,0001,555
16:0010,0001,373
16:3010,0001,466
17:0010,0001,122
17:3010,0001,010
18:0010,0001,141
18:3010,0001,271
19:0010,0001,710
19:3010,0002,165
20:0010,0001,898
20:3010,0001,640
21:0010,0001,056
21:3010,000459
22:0010,000-99
22:3010,000-662
23:0010,000804
23:3010,000800
ESTEX32026-10-24 23:30Limit 10,000 MWFlow 719 MW
TimeLimit MWFlow MW
00:0010,000660
00:3010,000666
01:0010,000674
01:3010,000651
02:0010,000676
02:3010,000621
03:0010,000667
03:3010,000700
04:0010,000709
04:3010,000510
05:0010,0003,429
05:3010,0003,199
06:0010,0003,271
06:3010,0003,246
07:0010,0003,853
07:3010,0004,415
08:0010,0004,384
08:3010,0004,336
09:0010,0004,413
09:3010,0004,450
10:0010,0004,435
10:3010,0004,365
11:0010,0003,932
11:3010,0003,480
12:0010,0003,360
12:3010,0003,508
13:0010,0003,368
13:3010,0003,276
14:0010,0003,062
14:3010,0002,954
15:0010,0002,070
15:3010,0001,332
16:0010,0001,153
16:3010,0001,229
17:0010,000895
17:3010,000927
18:0010,0001,106
18:3010,0001,271
19:0010,0001,680
19:3010,0002,046
20:0010,0001,709
20:3010,0001,422
21:0010,000764
21:3010,000266
22:0010,000-522
22:3010,000-870
23:0010,000396
23:3010,000719
ESTEX42026-10-24 23:30Limit 10,000 MWFlow 475 MW
TimeLimit MWFlow MW
00:0010,000411
00:3010,000397
01:0010,000411
01:3010,000383
02:0010,000414
02:3010,000365
03:0010,000419
03:3010,000452
04:0010,000458
04:3010,000255
05:0010,0003,180
05:3010,0002,949
06:0010,0003,016
06:3010,0002,988
07:0010,0003,590
07:3010,0004,146
08:0010,0004,119
08:3010,0004,055
09:0010,0004,113
09:3010,0004,130
10:0010,0004,103
10:3010,0004,023
11:0010,0003,584
11:3010,0003,146
12:0010,0003,047
12:3010,0003,203
13:0010,0003,069
13:3010,0002,979
14:0010,0002,746
14:3010,0002,628
15:0010,0001,756
15:3010,0001,028
16:0010,000854
16:3010,000916
17:0010,000556
17:3010,000570
18:0010,000750
18:3010,000911
19:0010,0001,323
19:3010,0001,690
20:0010,0001,365
20:3010,0001,087
21:0010,000445
21:3010,000-29
22:0010,000-797
22:3010,000-1,144
23:0010,000133
23:3010,000475
FLOWSTH2026-10-24 23:30Limit 8,800 MWFlow 6,488 MW
TimeLimit MWFlow MW
00:009,0005,403
00:309,0004,978
01:009,0003,832
01:309,0003,137
02:009,0002,882
02:309,0002,444
03:009,0002,369
03:309,0002,389
04:009,0002,624
04:309,0002,930
05:008,8003,068
05:308,8003,340
06:008,8003,655
06:308,8004,249
07:008,8004,181
07:308,8003,622
08:008,8003,587
08:308,8004,098
09:008,8004,790
09:308,8004,942
10:008,8004,931
10:308,8005,070
11:008,8005,557
11:308,8006,088
12:008,8006,226
12:308,8006,121
13:008,8006,576
13:308,8006,670
14:008,8007,353
14:308,8007,768
15:008,8008,010
15:308,8008,932
16:008,8008,959
16:308,8008,778
17:008,8009,939
17:308,80010,657
18:008,80010,420
18:308,80010,340
19:008,80010,275
19:308,8009,254
20:008,8009,326
20:308,8009,326
21:008,8009,622
21:308,8009,710
22:008,80010,107
22:308,80010,107
23:008,8007,373
23:308,8006,488
GM_SNOW5A2026-10-24 23:30Limit 3,800 MWFlow 1,335 MW
TimeLimit MWFlow MW
00:003,6501,277
00:303,6501,456
01:003,6501,527
01:303,6501,234
02:003,6501,079
02:303,650843
03:003,650818
03:303,650708
04:003,650656
04:303,650394
05:003,800818
05:303,8001,054
06:003,8001,056
06:303,800659
07:003,8001,257
07:303,8001,763
08:003,8001,830
08:303,8001,901
09:003,8001,871
09:303,8001,999
10:003,8001,460
10:303,8001,374
11:003,8001,435
11:303,8001,340
12:003,8001,519
12:303,8001,250
13:003,8001,198
13:303,8001,196
14:003,8001,129
14:303,8001,117
15:003,8001,294
15:303,8001,571
16:003,8001,571
16:303,8001,420
17:003,8001,336
17:303,8001,363
18:003,8001,592
18:303,8001,852
19:003,8001,518
19:303,8001,376
20:003,8001,422
20:303,8001,397
21:003,8001,379
21:303,8001,490
22:003,8001,432
22:303,8001,577
23:003,8001,578
23:303,8001,335
HARSPNBLY2026-10-24 23:30Limit 4,600 MWFlow 9,769 MW
TimeLimit MWFlow MW
00:006,0504,025
00:306,0504,100
01:006,0504,754
01:306,0504,566
02:006,0504,285
02:306,0504,084
03:006,0503,898
03:306,0503,332
04:006,0502,995
04:306,0502,596
05:006,2003,156
05:306,2003,054
06:006,2003,056
06:306,2002,964
07:006,2003,097
07:306,2003,285
08:004,6004,082
08:304,6005,014
09:004,6005,802
09:304,6006,801
10:004,6007,383
10:304,6008,817
11:004,6009,956
11:304,60011,130
12:004,60012,116
12:304,60012,448
13:004,60011,815
13:304,60011,843
14:004,60011,741
14:304,60011,750
15:004,60010,628
15:304,60010,067
16:004,60010,645
16:304,60010,555
17:004,60010,791
17:304,60010,891
18:004,60010,592
18:304,60010,420
19:004,6009,669
19:304,6009,691
20:004,60010,111
20:304,60010,156
21:004,60010,076
21:304,60010,404
22:004,60010,705
22:304,60010,973
23:004,6009,691
23:304,6009,769
NINSELEX2026-10-24 23:30Limit 10,000 MWFlow -191 MW
TimeLimit MWFlow MW
00:0010,000-201
00:3010,000-216
01:0010,000-219
01:3010,000-224
02:0010,000-219
02:3010,000-216
03:0010,000-210
03:3010,000-202
04:0010,000-194
04:3010,000-190
05:0010,000638
05:3010,000349
06:0010,000404
06:3010,000457
07:0010,0001,049
07:3010,0001,636
08:0010,0001,452
08:3010,0001,417
09:0010,0001,543
09:3010,0001,670
10:0010,0001,682
10:3010,0001,707
11:0010,0001,294
11:3010,000855
12:0010,000824
12:3010,000835
13:0010,000801
13:3010,000762
14:0010,000633
14:3010,000516
15:0010,000303
15:3010,00079
16:0010,000318
16:3010,000555
17:0010,00018
17:3010,000-537
18:0010,000-478
18:3010,000-407
19:0010,000-171
19:3010,00066
20:0010,000-286
20:3010,000-646
21:0010,000-936
21:3010,000-1,220
22:0010,000-1,441
22:3010,000-1,667
23:0010,000-188
23:3010,000-191
NKILGRMO2026-10-24 23:30Limit 10,000 MWFlow 4,590 MW
TimeLimit MWFlow MW
00:0010,000518
00:3010,000416
01:0010,000357
01:3010,000307
02:0010,000304
02:3010,000307
03:0010,000299
03:3010,000265
04:0010,000250
04:3010,000272
05:0010,000984
05:3010,000762
06:0010,000733
06:3010,000679
07:0010,000732
07:3010,000804
08:0010,0001,160
08:3010,0001,403
09:0010,0001,810
09:3010,0002,253
10:0010,0002,712
10:3010,0003,552
11:0010,0004,157
11:3010,0004,760
12:0010,0005,260
12:3010,0005,454
13:0010,0005,335
13:3010,0005,388
14:0010,0005,285
14:3010,0005,346
15:0010,0004,349
15:3010,0004,178
16:0010,0004,442
16:3010,0004,553
17:0010,0004,785
17:3010,0004,819
18:0010,0004,892
18:3010,0004,894
19:0010,0004,850
19:3010,0004,873
20:0010,0004,878
20:3010,0004,853
21:0010,0004,763
21:3010,0004,839
22:0010,0004,872
22:3010,0004,854
23:0010,0004,475
23:3010,0004,590
SCOTEX2026-10-24 23:30Limit 2,800 MWFlow 9,389 MW
TimeLimit MWFlow MW
00:004,3004,012
00:304,3003,892
01:004,3004,258
01:304,3004,083
02:004,3003,813
02:304,3003,618
03:004,3003,437
03:304,3002,868
04:004,3002,531
04:304,3002,162
05:004,3002,754
05:304,3002,603
06:004,3002,554
06:304,3002,466
07:004,3002,599
07:302,8002,828
08:002,8003,673
08:302,8004,604
09:002,8005,375
09:302,8006,199
10:002,8006,609
10:302,8007,790
11:002,8008,678
11:302,8009,601
12:002,80010,358
12:302,80010,626
13:002,8009,957
13:302,80010,006
14:002,8009,915
14:302,8009,925
15:002,8008,795
15:302,8008,347
16:002,8009,043
16:302,8009,205
17:002,8009,699
17:302,80010,072
18:002,80010,182
18:302,80010,190
19:002,8009,607
19:302,8009,664
20:002,8009,679
20:302,8009,690
21:002,8009,587
21:302,8009,688
22:002,8009,752
22:302,8009,775
23:002,8009,308
23:302,8009,389
SEIMPPR232026-10-24 23:30Limit 6,950 MWFlow 3,858 MW
TimeLimit MWFlow MW
00:006,6502,135
00:306,6501,768
01:006,6501,318
01:306,650575
02:006,650229
02:306,650-58
03:006,650-137
03:306,650-198
04:006,650119
04:306,650314
05:006,950577
05:306,950792
06:006,950867
06:306,9501,057
07:006,950784
07:306,950395
08:006,950564
08:306,950860
09:006,9501,011
09:306,9501,230
10:006,9501,295
10:306,9501,467
11:006,9501,787
11:306,9502,174
12:006,9502,372
12:306,9502,098
13:006,9502,324
13:306,9502,343
14:006,9502,657
14:306,9502,734
15:006,9503,473
15:306,9504,226
16:006,9504,289
16:306,9504,343
17:006,9504,954
17:306,9505,152
18:006,9504,979
18:306,9504,855
19:006,9504,448
19:306,9504,209
20:006,9504,267
20:306,9504,468
21:006,9504,874
21:306,9505,229
22:006,9505,767
22:306,9505,890
23:006,9504,454
23:306,9503,858
SSE_GRMO2026-10-24 23:30Limit 9,999 MWFlow 4,613 MW
TimeLimit MWFlow MW
00:009,999430
00:309,999294
01:009,999236
01:309,999182
02:009,999185
02:309,999194
03:009,999192
03:309,999160
04:009,999150
04:309,999180
05:009,999885
05:309,999684
06:009,999669
06:309,999626
07:009,999801
07:309,999898
08:009,9991,287
08:309,9991,555
09:009,9992,006
09:309,9992,464
10:009,9992,942
10:309,9993,779
11:009,9994,299
11:309,9994,902
12:009,9995,409
12:309,9995,603
13:009,9995,487
13:309,9995,541
14:009,9995,440
14:309,9995,500
15:009,9994,430
15:309,9994,259
16:009,9994,572
16:309,9994,686
17:009,9994,940
17:309,9994,960
18:009,9995,041
18:309,9995,037
19:009,9994,999
19:309,9995,027
20:009,9995,042
20:309,9995,011
21:009,9994,893
21:309,9994,984
22:009,9995,032
22:309,9995,015
23:009,9994,495
23:309,9994,613
SSE_SP22026-10-24 23:30Limit 2,000 MWFlow 4,857 MW
TimeLimit MWFlow MW
00:001,8502,004
00:301,8501,949
01:001,8502,097
01:301,8502,053
02:001,8502,006
02:301,8501,928
03:001,8501,862
03:301,8501,756
04:001,8501,569
04:301,8501,484
05:002,0001,348
05:302,0001,127
06:002,0001,103
06:302,0001,068
07:002,0001,114
07:302,0001,182
08:002,0001,493
08:302,0001,740
09:002,0002,125
09:302,0002,587
10:002,0003,072
10:302,0003,920
11:002,0004,532
11:302,0005,139
12:002,0005,611
12:302,0005,784
13:002,0005,689
13:302,0005,746
14:002,0005,658
14:302,0005,737
15:002,0004,743
15:302,0004,604
16:002,0004,855
16:302,0004,932
17:002,0005,135
17:302,0005,178
18:002,0005,263
18:302,0005,274
19:002,0005,240
19:302,0005,263
20:002,0005,243
20:302,0005,222
21:002,0005,133
21:302,0005,168
22:002,0005,167
22:302,0005,124
23:002,0004,755
23:302,0004,857
SSEN_S2026-10-24 23:30Limit 1,600 MWFlow 3,819 MW
TimeLimit MWFlow MW
00:001,600995
00:301,600947
01:001,6001,104
01:301,6001,083
02:001,6001,069
02:301,6001,048
03:001,6001,026
03:301,600960
04:001,600840
04:301,600852
05:001,600812
05:301,600752
06:001,600792
06:301,600800
07:001,600826
07:301,600932
08:001,6001,223
08:301,6001,483
09:001,6001,834
09:301,6002,219
10:001,6002,639
10:301,6003,332
11:001,6003,906
11:301,6004,339
12:001,6004,629
12:301,6004,705
13:001,6004,557
13:301,6004,600
14:001,6004,610
14:301,6004,667
15:001,6003,695
15:301,6003,510
16:001,6003,676
16:301,6003,744
17:001,6003,890
17:301,6003,946
18:001,6003,993
18:301,6004,028
19:001,6004,012
19:301,6004,024
20:001,6003,991
20:301,6003,955
21:001,6003,965
21:301,6003,987
22:001,6004,001
22:301,6003,976
23:001,6003,681
23:301,6003,819
SSHARN32026-10-24 23:30Limit 6,300 MWFlow 12,773 MW
TimeLimit MWFlow MW
00:006,7507,299
00:306,7507,343
01:006,7507,928
01:306,7507,661
02:006,7507,257
02:306,7506,887
03:006,7506,550
03:306,7505,941
04:006,7505,510
04:306,7505,064
05:006,3505,584
05:306,3505,471
06:006,3505,480
06:306,3505,427
07:006,3505,625
07:306,3505,811
08:006,3006,715
08:306,3007,687
09:006,3008,575
09:306,3009,549
10:006,30010,159
10:306,30011,623
11:006,30012,798
11:306,30014,011
12:006,30015,053
12:306,30015,411
13:006,30014,797
13:306,30014,827
14:006,30014,731
14:306,30014,730
15:006,30013,587
15:306,30013,047
16:006,30013,646
16:306,30013,525
17:006,30013,702
17:306,30013,761
18:006,30013,432
18:306,30013,211
19:006,30012,447
19:306,30012,488
20:006,30012,951
20:306,30012,999
21:006,30012,897
21:306,30013,283
22:006,30013,590
22:306,30013,914
23:006,30012,672
23:306,30012,773

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