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Data as of 2026-09-20
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Built 2026-09-21 (21 September 2026)

AECI Demand Forecast Accuracy: Error, Bias and Worst Miss, 21 August to 20 September 2026

The day-ahead demand forecast for AECI was off by 4.2% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 65% of hours landed within 5% of the reading. Its bias was +0.4%: it ran close to balanced on average. The largest miss was 446 MW (12.0%) too low at 20 Sept 2026, 13:00 CDT (UTC-05:00). Dates and times are local (America/Chicago).

Key Facts

  • The day-ahead demand forecast for AECI was off by 4.2% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 65% of hours landed within 5% of the reading. Its bias was +0.4%: it ran close to balanced on average. The largest miss was 446 MW (12.0%) too low at 20 Sept 2026, 13:00 CDT (UTC-05:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, AECI came 28 (1 is the smallest error).
  • On average the forecast differed from reported demand by 126 MW, against average demand of 3,046 MW.
  • The forecast was above reported demand in 55% of compared hours.

Forecast Error at a Glance

719 hours from 21 August to 20 September 2026
Average error4.2%
Bias+0.4%
Hours within 5%65%
Worst miss446 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+5 MW per hour on average): the forecast ran close to balanced on average. The worst miss was 446 MW (12.0%) too low at 20 Sept 2026, 13:00 CDT (UTC-05:00): forecast 3,267 MW, reported 3,713 MW.

Source: U.S. Energy Information Administration (EIA). (US Government work, public domain) Data as of 2026-09-20. Accuracy is computed by World Power Monitor from the operator's hourly forecast and reported demand.

Forecast and Reported Demand, Last 7 Days

Local time, to 20 Sept 2026, 20:00 CDT (UTC-05:00)
AECI day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for AECI over the last 7 days of the window, to 20 Sept 2026, 20:00 CDT (UTC-05:00). Gaps are hours with a missing, zero or implausible report. 0 1,250 2,500 3,750 5,000 13 Sept, 21:0014 Sept, 21:0015 Sept, 21:0016 Sept, 21:0017 Sept, 21:0018 Sept, 21:0019 Sept, 21:00
Hourly reported demand and the day-ahead forecast for AECI over the last 7 days of the window, to 20 Sept 2026, 20:00 CDT (UTC-05:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-09-20
AECI day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 21:002,899 MW3,102 MW
13 Sept, 22:002,598 MW2,807 MW
13 Sept, 23:002,317 MW2,506 MW
14 Sept, 00:002,139 MW2,265 MW
14 Sept, 01:002,014 MW2,118 MW
14 Sept, 02:001,925 MW1,977 MW
14 Sept, 03:001,909 MW1,905 MW
14 Sept, 04:001,939 MW1,888 MW
14 Sept, 05:002,015 MW1,913 MW
14 Sept, 06:002,143 MW2,004 MW
14 Sept, 07:002,227 MW2,139 MW
14 Sept, 08:002,334 MW2,248 MW
14 Sept, 09:002,543 MW2,385 MW
14 Sept, 10:002,756 MW2,590 MW
14 Sept, 11:003,059 MW2,839 MW
14 Sept, 12:003,367 MW3,113 MW
14 Sept, 13:003,626 MW3,395 MW
14 Sept, 14:003,856 MW3,648 MW
14 Sept, 15:004,034 MW3,856 MW
14 Sept, 16:004,145 MW4,025 MW
14 Sept, 17:004,234 MW4,130 MW
14 Sept, 18:004,141 MW4,186 MW
14 Sept, 19:003,891 MW4,052 MW
14 Sept, 20:003,699 MW3,824 MW
14 Sept, 21:003,424 MW3,611 MW
14 Sept, 22:003,129 MW3,341 MW
14 Sept, 23:002,841 MW3,033 MW
15 Sept, 00:002,625 MW2,780 MW
15 Sept, 01:002,484 MW2,603 MW
15 Sept, 02:002,376 MW2,447 MW
15 Sept, 03:002,309 MW2,336 MW
15 Sept, 04:002,281 MW2,280 MW
15 Sept, 05:002,363 MW2,276 MW
15 Sept, 06:002,464 MW2,345 MW
15 Sept, 07:002,543 MW2,438 MW
15 Sept, 08:002,684 MW2,529 MW
15 Sept, 09:002,972 MW2,721 MW
15 Sept, 10:003,318 MW3,019 MW
15 Sept, 11:003,694 MW3,362 MW
15 Sept, 12:003,961 MW3,702 MW
15 Sept, 13:004,240 MW3,985 MW
15 Sept, 14:004,392 MW4,210 MW
15 Sept, 15:004,489 MW4,372 MW
15 Sept, 16:004,514 MW4,457 MW
15 Sept, 17:004,488 MW4,479 MW
15 Sept, 18:004,071 MW4,416 MW
15 Sept, 19:004,063 MW4,212 MW
15 Sept, 20:003,806 MW3,956 MW
15 Sept, 21:003,520 MW3,720 MW
15 Sept, 22:003,160 MW3,407 MW
15 Sept, 23:002,809 MW3,052 MW
16 Sept, 00:002,602 MW2,747 MW
16 Sept, 01:002,461 MW2,561 MW
16 Sept, 02:002,310 MW2,388 MW
16 Sept, 03:002,238 MW2,264 MW
16 Sept, 04:002,218 MW2,197 MW
16 Sept, 05:002,259 MW2,189 MW
16 Sept, 06:002,424 MW2,264 MW
16 Sept, 07:002,472 MW2,399 MW
16 Sept, 08:002,564 MW2,467 MW
16 Sept, 09:002,784 MW2,603 MW
16 Sept, 10:003,108 MW2,832 MW
16 Sept, 11:003,419 MW3,137 MW
16 Sept, 12:003,689 MW3,457 MW
16 Sept, 13:003,884 MW3,714 MW
16 Sept, 14:004,055 MW3,902 MW
16 Sept, 15:004,141 MW4,041 MW
16 Sept, 16:004,197 MW4,124 MW
16 Sept, 17:004,197 MW4,176 MW
16 Sept, 18:004,094 MW4,168 MW
16 Sept, 19:003,855 MW4,012 MW
16 Sept, 20:003,627 MW3,789 MW
16 Sept, 21:003,370 MW3,571 MW
16 Sept, 22:003,027 MW3,286 MW
16 Sept, 23:002,742 MW2,959 MW
17 Sept, 00:002,517 MW2,675 MW
17 Sept, 01:002,357 MW2,508 MW
17 Sept, 02:002,239 MW2,320 MW
17 Sept, 03:002,167 MW2,216 MW
17 Sept, 04:002,142 MW2,178 MW
17 Sept, 05:002,240 MW2,183 MW
17 Sept, 06:002,375 MW2,240 MW
17 Sept, 07:002,433 MW2,377 MW
17 Sept, 08:002,591 MW2,459 MW
17 Sept, 09:002,869 MW2,642 MW
17 Sept, 10:003,211 MW2,930 MW
17 Sept, 11:003,596 MW3,288 MW
17 Sept, 12:003,924 MW3,646 MW
17 Sept, 13:004,160 MW3,956 MW
17 Sept, 14:004,310 MW4,174 MW
17 Sept, 15:004,384 MW4,311 MW
17 Sept, 16:004,433 MW4,381 MW
17 Sept, 17:004,463 MW4,424 MW
17 Sept, 18:004,311 MW4,401 MW
17 Sept, 19:004,026 MW4,222 MW
17 Sept, 20:003,826 MW3,963 MW
17 Sept, 21:003,526 MW3,739 MW
17 Sept, 22:003,171 MW3,434 MW
17 Sept, 23:002,896 MW3,108 MW
18 Sept, 00:002,633 MW2,816 MW
18 Sept, 01:002,477 MW2,631 MW
18 Sept, 02:002,339 MW2,428 MW
18 Sept, 03:002,262 MW2,313 MW
18 Sept, 04:002,230 MW2,231 MW
18 Sept, 05:002,292 MW2,232 MW
18 Sept, 06:002,435 MW2,304 MW
18 Sept, 07:002,490 MW2,433 MW
18 Sept, 08:002,628 MW2,516 MW
18 Sept, 09:002,921 MW2,698 MW
18 Sept, 10:003,282 MW2,996 MW
18 Sept, 11:003,653 MW3,361 MW
18 Sept, 12:003,943 MW3,695 MW
18 Sept, 13:004,171 MW3,982 MW
18 Sept, 14:004,340 MW4,189 MW
18 Sept, 15:004,430 MW4,328 MW
18 Sept, 16:004,477 MW4,416 MW
18 Sept, 17:004,446 MW4,431 MW
18 Sept, 18:004,217 MW4,371 MW
18 Sept, 19:003,910 MW4,127 MW
18 Sept, 20:003,667 MW3,828 MW
18 Sept, 21:003,386 MW3,582 MW
18 Sept, 22:003,131 MW3,313 MW
18 Sept, 23:002,854 MW3,055 MW
19 Sept, 00:002,610 MW2,784 MW
19 Sept, 01:002,409 MW2,599 MW
19 Sept, 02:002,276 MW2,373 MW
19 Sept, 03:002,173 MW2,240 MW
19 Sept, 04:002,128 MW2,161 MW
19 Sept, 05:002,114 MW2,118 MW
19 Sept, 06:002,146 MW2,120 MW
19 Sept, 07:002,241 MW2,162 MW
19 Sept, 08:002,458 MW2,277 MW
19 Sept, 09:002,776 MW2,539 MW
19 Sept, 10:003,106 MW2,855 MW
19 Sept, 11:003,433 MW3,193 MW
19 Sept, 12:003,695 MW3,500 MW
19 Sept, 13:003,907 MW3,759 MW
19 Sept, 14:004,087 MW3,951 MW
19 Sept, 15:004,235 MW4,110 MW
19 Sept, 16:004,335 MW4,246 MW
19 Sept, 17:004,307 MW4,313 MW
19 Sept, 18:004,057 MW4,255 MW
19 Sept, 19:003,736 MW3,990 MW
19 Sept, 20:003,470 MW3,668 MW
19 Sept, 21:003,169 MW3,396 MW
19 Sept, 22:002,923 MW3,119 MW
19 Sept, 23:002,631 MW2,851 MW
20 Sept, 00:002,450 MW2,600 MW
20 Sept, 01:002,278 MW2,426 MW
20 Sept, 02:002,180 MW2,263 MW
20 Sept, 03:002,078 MW2,156 MW
20 Sept, 04:002,008 MW2,056 MW
20 Sept, 05:001,992 MW2,005 MW
20 Sept, 06:002,011 MW1,993 MW
20 Sept, 07:002,080 MW2,076 MW
20 Sept, 08:002,315 MW2,207 MW
20 Sept, 09:002,567 MW2,385 MW
20 Sept, 10:002,849 MW2,577 MW
20 Sept, 11:003,153 MW2,809 MW
20 Sept, 12:003,465 MW3,055 MW
20 Sept, 13:003,713 MW3,267 MW
20 Sept, 14:003,851 MW3,415 MW
20 Sept, 15:003,874 MW3,518 MW
20 Sept, 16:003,859 MW3,584 MW
20 Sept, 17:003,724 MW3,599 MW
20 Sept, 18:003,470 MW3,531 MW
20 Sept, 19:003,256 MW3,352 MW
20 Sept, 20:003,086 MW3,121 MW

Assumptions

  • Only hours with both a forecast and a positive demand reading count (719 of 720 hours in the window). Missing and zero values, and readings under 30% or over 3 times the grid's own median for the window, are treated as reporting faults and left out.
  • Error is (forecast minus reported demand) divided by reported demand; average error uses absolute values so high and low misses do not cancel. Bias keeps the sign and does cancel.
  • Reported demand is preliminary and may be revised. A 30 day window is a short sample and one heat wave or holiday can move these figures.
  • US figures are for the EIA balancing authority or region named on this page. US and European grids are ranked separately.