Statistics
Page built 2026-09-21
Data as of 2026-09-20
Search
Built 2026-09-21 (21 September 2026)

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

The day-ahead demand forecast for PGE was off by 1.9% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 92% of hours landed within 5% of the reading. Its bias was +1.0%: it ran high on average, an over forecast. The largest miss was 367 MW (13.6%) too high at 18 Sept 2026, 17:00 PDT (UTC-07:00). Dates and times are local (America/Los_Angeles).

Key Facts

  • The day-ahead demand forecast for PGE was off by 1.9% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 92% of hours landed within 5% of the reading. Its bias was +1.0%: it ran high on average, an over forecast. The largest miss was 367 MW (13.6%) too high at 18 Sept 2026, 17:00 PDT (UTC-07:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, PGE came 4 (1 is the smallest error).
  • On average the forecast differed from reported demand by 48 MW, against average demand of 2,572 MW.
  • The forecast was above reported demand in 66% of compared hours.

Forecast Error at a Glance

719 hours from 21 August to 20 September 2026
Average error1.9%
Bias+1.0%
Hours within 5%92%
Worst miss367 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+24 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 367 MW (13.6%) too high at 18 Sept 2026, 17:00 PDT (UTC-07:00): forecast 3,062 MW, reported 2,695 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, 18:00 PDT (UTC-07:00)
PGE day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for PGE over the last 7 days of the window, to 20 Sept 2026, 18:00 PDT (UTC-07:00). Gaps are hours with a missing, zero or implausible report. 0 1,000 2,000 3,000 4,000 13 Sept, 19:0014 Sept, 19:0015 Sept, 19:0016 Sept, 19:0017 Sept, 19:0018 Sept, 19:0019 Sept, 19:00
Hourly reported demand and the day-ahead forecast for PGE over the last 7 days of the window, to 20 Sept 2026, 18:00 PDT (UTC-07:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-09-20
PGE day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 19:002,735 MW2,711 MW
13 Sept, 20:002,712 MW2,700 MW
13 Sept, 21:002,610 MW2,615 MW
13 Sept, 22:002,449 MW2,462 MW
13 Sept, 23:002,287 MW2,313 MW
14 Sept, 00:002,177 MW2,199 MW
14 Sept, 01:002,107 MW2,109 MW
14 Sept, 02:002,078 MW2,078 MW
14 Sept, 03:002,072 MW2,079 MW
14 Sept, 04:002,133 MW2,132 MW
14 Sept, 05:002,268 MW2,280 MW
14 Sept, 06:002,492 MW2,501 MW
14 Sept, 07:002,638 MW2,643 MW
14 Sept, 08:002,658 MW2,650 MW
14 Sept, 09:002,635 MW2,625 MW
14 Sept, 10:002,586 MW2,616 MW
14 Sept, 11:002,616 MW2,614 MW
14 Sept, 12:002,631 MW2,627 MW
14 Sept, 13:002,581 MW2,638 MW
14 Sept, 14:002,564 MW2,643 MW
14 Sept, 15:002,562 MW2,663 MW
14 Sept, 16:002,612 MW2,721 MW
14 Sept, 17:002,727 MW2,815 MW
14 Sept, 18:002,809 MW2,870 MW
14 Sept, 19:002,828 MW2,891 MW
14 Sept, 20:002,803 MW2,851 MW
14 Sept, 21:002,689 MW2,725 MW
14 Sept, 22:002,516 MW2,563 MW
14 Sept, 23:002,344 MW2,398 MW
15 Sept, 00:002,226 MW2,274 MW
15 Sept, 01:002,154 MW2,188 MW
15 Sept, 02:002,111 MW2,142 MW
15 Sept, 03:002,102 MW2,131 MW
15 Sept, 04:002,147 MW2,179 MW
15 Sept, 05:002,298 MW2,297 MW
15 Sept, 06:002,514 MW2,536 MW
15 Sept, 07:002,667 MW2,678 MW
15 Sept, 08:002,665 MW2,676 MW
15 Sept, 09:002,637 MW2,641 MW
15 Sept, 10:002,642 MW2,630 MW
15 Sept, 11:002,653 MW2,631 MW
15 Sept, 12:002,664 MW2,644 MW
15 Sept, 13:002,636 MW2,656 MW
15 Sept, 14:002,612 MW2,664 MW
15 Sept, 15:002,628 MW2,683 MW
15 Sept, 16:002,694 MW2,743 MW
15 Sept, 17:002,755 MW2,816 MW
15 Sept, 18:002,814 MW2,851 MW
15 Sept, 19:002,845 MW2,874 MW
15 Sept, 20:002,817 MW2,853 MW
15 Sept, 21:002,724 MW2,740 MW
15 Sept, 22:002,537 MW2,589 MW
15 Sept, 23:002,386 MW2,417 MW
16 Sept, 00:002,253 MW2,259 MW
16 Sept, 01:002,172 MW2,190 MW
16 Sept, 02:002,130 MW2,144 MW
16 Sept, 03:002,114 MW2,130 MW
16 Sept, 04:002,163 MW2,174 MW
16 Sept, 05:002,302 MW2,311 MW
16 Sept, 06:002,528 MW2,531 MW
16 Sept, 07:002,651 MW2,648 MW
16 Sept, 08:002,622 MW2,616 MW
16 Sept, 09:002,568 MW2,550 MW
16 Sept, 10:002,537 MW2,535 MW
16 Sept, 11:002,551 MW2,552 MW
16 Sept, 12:002,590 MW2,607 MW
16 Sept, 13:002,627 MW2,674 MW
16 Sept, 14:002,686 MW2,744 MW
16 Sept, 15:002,778 MW2,830 MW
16 Sept, 16:002,896 MW2,968 MW
16 Sept, 17:003,038 MW3,096 MW
16 Sept, 18:003,088 MW3,128 MW
16 Sept, 19:003,072 MW3,109 MW
16 Sept, 20:003,016 MW3,041 MW
16 Sept, 21:002,890 MW2,902 MW
16 Sept, 22:002,696 MW2,714 MW
16 Sept, 23:002,479 MW2,524 MW
17 Sept, 00:002,334 MW2,400 MW
17 Sept, 01:002,232 MW2,284 MW
17 Sept, 02:002,175 MW2,208 MW
17 Sept, 03:002,141 MW2,181 MW
17 Sept, 04:002,180 MW2,207 MW
17 Sept, 05:002,300 MW2,318 MW
17 Sept, 06:002,515 MW2,529 MW
17 Sept, 07:002,639 MW2,643 MW
17 Sept, 08:002,622 MW2,637 MW
17 Sept, 09:002,687 MW2,613 MW
17 Sept, 10:002,595 MW2,628 MW
17 Sept, 11:002,620 MW2,691 MW
17 Sept, 12:002,697 MW2,762 MW
17 Sept, 13:002,790 MW2,871 MW
17 Sept, 14:002,893 MW2,982 MW
17 Sept, 15:003,019 MW3,092 MW
17 Sept, 16:003,165 MW3,253 MW
17 Sept, 17:003,270 MW3,328 MW
17 Sept, 18:003,297 MW3,329 MW
17 Sept, 19:003,230 MW3,286 MW
17 Sept, 20:003,127 MW3,187 MW
17 Sept, 21:002,973 MW3,021 MW
17 Sept, 22:002,747 MW2,816 MW
17 Sept, 23:002,529 MW2,607 MW
18 Sept, 00:002,366 MW2,419 MW
18 Sept, 01:002,245 MW2,263 MW
18 Sept, 02:002,177 MW2,190 MW
18 Sept, 03:002,141 MW2,155 MW
18 Sept, 04:002,164 MW2,179 MW
18 Sept, 05:002,272 MW2,281 MW
18 Sept, 06:002,465 MW2,469 MW
18 Sept, 07:002,609 MW2,597 MW
18 Sept, 08:002,668 MW2,620 MW
18 Sept, 09:002,694 MW2,612 MW
18 Sept, 10:002,713 MW2,603 MW
18 Sept, 11:002,711 MW2,586 MW
18 Sept, 12:002,705 MW2,594 MW
18 Sept, 13:002,659 MW2,630 MW
18 Sept, 14:002,596 MW2,690 MW
18 Sept, 15:002,570 MW2,793 MW
18 Sept, 16:002,596 MW2,921 MW
18 Sept, 17:002,695 MW3,062 MW
18 Sept, 18:002,757 MW3,049 MW
18 Sept, 19:002,752 MW3,004 MW
18 Sept, 20:002,708 MW2,927 MW
18 Sept, 21:002,630 MW2,801 MW
18 Sept, 22:002,502 MW2,647 MW
18 Sept, 23:002,355 MW2,483 MW
19 Sept, 00:002,245 MW2,327 MW
19 Sept, 01:002,148 MW2,216 MW
19 Sept, 02:002,096 MW2,140 MW
19 Sept, 03:002,071 MW2,098 MW
19 Sept, 04:002,074 MW2,079 MW
19 Sept, 05:002,122 MW2,104 MW
19 Sept, 06:002,217 MW2,194 MW
19 Sept, 07:002,318 MW2,285 MW
19 Sept, 08:002,408 MW2,352 MW
19 Sept, 09:002,466 MW2,369 MW
19 Sept, 10:002,476 MW2,394 MW
19 Sept, 11:002,459 MW2,368 MW
19 Sept, 12:002,400 MW2,364 MW
19 Sept, 13:002,320 MW2,408 MW
19 Sept, 14:002,321 MW2,505 MW
19 Sept, 15:002,408 MW2,560 MW
19 Sept, 16:002,508 MW2,678 MW
19 Sept, 17:002,647 MW2,849 MW
19 Sept, 18:002,721 MW2,867 MW
19 Sept, 19:002,738 MW2,866 MW
19 Sept, 20:002,687 MW2,803 MW
19 Sept, 21:002,587 MW2,669 MW
19 Sept, 22:002,466 MW2,552 MW
19 Sept, 23:002,337 MW2,417 MW
20 Sept, 00:002,217 MW2,306 MW
20 Sept, 01:002,134 MW2,170 MW
20 Sept, 02:002,072 MW2,114 MW
20 Sept, 03:002,048 MW2,083 MW
20 Sept, 04:002,043 MW2,077 MW
20 Sept, 05:002,073 MW2,106 MW
20 Sept, 06:002,155 MW2,180 MW
20 Sept, 07:002,233 MW2,255 MW
20 Sept, 08:002,330 MW2,325 MW
20 Sept, 09:002,399 MW2,363 MW
20 Sept, 10:002,418 MW2,373 MW
20 Sept, 11:002,389 MW2,389 MW
20 Sept, 12:002,328 MW2,400 MW
20 Sept, 13:002,340 MW2,458 MW
20 Sept, 14:002,413 MW2,541 MW
20 Sept, 15:002,525 MW2,659 MW
20 Sept, 16:002,684 MW2,822 MW
20 Sept, 17:002,859 MW2,985 MW
20 Sept, 18:002,943 MW3,053 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.