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

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

The day-ahead demand forecast for IPCO was off by 5.7% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 52% of hours landed within 5% of the reading. Its bias was -0.5%: it ran low on average, an under forecast. The largest miss was 638 MW (29.5%) too high at 7 Sept 2026, 15:00 PDT (UTC-07:00). Dates and times are local (America/Los_Angeles).

Key Facts

  • The day-ahead demand forecast for IPCO was off by 5.7% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 52% of hours landed within 5% of the reading. Its bias was -0.5%: it ran low on average, an under forecast. The largest miss was 638 MW (29.5%) too high at 7 Sept 2026, 15:00 PDT (UTC-07:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, IPCO came 35 (1 is the smallest error).
  • On average the forecast differed from reported demand by 130 MW, against average demand of 2,328 MW.
  • The forecast was above reported demand in 48% of compared hours.

Forecast Error at a Glance

719 hours from 21 August to 20 September 2026
Average error5.7%
Bias-0.5%
Hours within 5%52%
Worst miss638 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-19 MW per hour on average): the forecast ran low on average, an under forecast. The worst miss was 638 MW (29.5%) too high at 7 Sept 2026, 15:00 PDT (UTC-07:00): forecast 2,804 MW, reported 2,166 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)
IPCO day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for IPCO 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. 0 750 1,500 2,250 3,000 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 IPCO 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
IPCO day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 19:002,246 MW2,054 MW
13 Sept, 20:002,111 MW1,962 MW
13 Sept, 21:001,961 MW1,834 MW
13 Sept, 22:001,828 MW1,713 MW
13 Sept, 23:001,733 MW1,638 MW
14 Sept, 00:001,682 MW1,711 MW
14 Sept, 01:001,648 MW1,841 MW
14 Sept, 02:001,648 MW1,744 MW
14 Sept, 03:001,670 MW1,803 MW
14 Sept, 04:001,762 MW1,940 MW
14 Sept, 05:001,905 MW2,114 MW
14 Sept, 06:002,012 MW2,185 MW
14 Sept, 07:001,976 MW2,176 MW
14 Sept, 08:002,000 MW2,095 MW
14 Sept, 09:002,085 MW2,057 MW
14 Sept, 10:002,187 MW2,043 MW
14 Sept, 11:002,187 MW2,035 MW
14 Sept, 12:002,214 MW2,042 MW
14 Sept, 13:002,153 MW2,066 MW
14 Sept, 14:002,143 MW2,088 MW
14 Sept, 15:002,211 MW2,119 MW
14 Sept, 16:002,275 MW2,141 MW
14 Sept, 17:002,313 MW2,171 MW
14 Sept, 18:002,313 MW2,170 MW
14 Sept, 19:002,319 MW2,153 MW
14 Sept, 20:002,216 MW2,076 MW
14 Sept, 21:002,074 MW1,975 MW
14 Sept, 22:001,941 MW1,876 MW
14 Sept, 23:001,829 MW1,825 MW
15 Sept, 00:001,796 MW1,857 MW
15 Sept, 01:001,765 MW1,877 MW
15 Sept, 02:001,744 MW1,815 MW
15 Sept, 03:001,770 MW1,858 MW
15 Sept, 04:001,840 MW1,958 MW
15 Sept, 05:002,000 MW2,046 MW
15 Sept, 06:002,098 MW2,138 MW
15 Sept, 07:002,143 MW2,233 MW
15 Sept, 08:002,142 MW2,287 MW
15 Sept, 09:002,140 MW2,290 MW
15 Sept, 10:002,127 MW2,288 MW
15 Sept, 11:002,134 MW2,285 MW
15 Sept, 12:002,157 MW2,299 MW
15 Sept, 13:002,210 MW2,354 MW
15 Sept, 14:002,271 MW2,410 MW
15 Sept, 15:002,330 MW2,471 MW
15 Sept, 16:002,383 MW2,492 MW
15 Sept, 17:002,387 MW2,468 MW
15 Sept, 18:002,391 MW2,408 MW
15 Sept, 19:002,379 MW2,311 MW
15 Sept, 20:002,272 MW2,162 MW
15 Sept, 21:002,136 MW1,997 MW
15 Sept, 22:001,977 MW1,879 MW
15 Sept, 23:001,881 MW1,810 MW
16 Sept, 00:001,808 MW1,859 MW
16 Sept, 01:001,777 MW1,913 MW
16 Sept, 02:001,755 MW1,818 MW
16 Sept, 03:001,786 MW1,849 MW
16 Sept, 04:001,835 MW1,966 MW
16 Sept, 05:001,975 MW2,122 MW
16 Sept, 06:002,078 MW2,197 MW
16 Sept, 07:002,097 MW2,160 MW
16 Sept, 08:002,134 MW2,086 MW
16 Sept, 09:002,124 MW2,078 MW
16 Sept, 10:002,112 MW2,114 MW
16 Sept, 11:002,139 MW2,139 MW
16 Sept, 12:002,199 MW2,157 MW
16 Sept, 13:002,279 MW2,190 MW
16 Sept, 14:002,354 MW2,220 MW
16 Sept, 15:002,407 MW2,248 MW
16 Sept, 16:002,566 MW2,248 MW
16 Sept, 17:002,576 MW2,227 MW
16 Sept, 18:002,535 MW2,172 MW
16 Sept, 19:002,497 MW2,110 MW
16 Sept, 20:002,363 MW2,026 MW
16 Sept, 21:002,194 MW1,927 MW
16 Sept, 22:002,041 MW1,830 MW
16 Sept, 23:001,920 MW1,764 MW
17 Sept, 00:001,864 MW1,867 MW
17 Sept, 01:001,798 MW1,962 MW
17 Sept, 02:001,766 MW1,823 MW
17 Sept, 03:001,777 MW1,850 MW
17 Sept, 04:001,841 MW1,952 MW
17 Sept, 05:001,979 MW2,103 MW
17 Sept, 06:002,076 MW2,171 MW
17 Sept, 07:002,107 MW2,131 MW
17 Sept, 08:002,144 MW2,060 MW
17 Sept, 09:002,199 MW2,083 MW
17 Sept, 10:002,263 MW2,149 MW
17 Sept, 11:002,324 MW2,198 MW
17 Sept, 12:002,410 MW2,237 MW
17 Sept, 13:002,494 MW2,297 MW
17 Sept, 14:002,555 MW2,346 MW
17 Sept, 15:002,628 MW2,388 MW
17 Sept, 16:002,669 MW2,393 MW
17 Sept, 17:002,648 MW2,366 MW
17 Sept, 18:002,553 MW2,302 MW
17 Sept, 19:002,492 MW2,216 MW
17 Sept, 20:002,374 MW2,097 MW
17 Sept, 21:002,202 MW1,964 MW
17 Sept, 22:002,039 MW1,852 MW
17 Sept, 23:001,910 MW1,783 MW
18 Sept, 00:001,824 MW1,874 MW
18 Sept, 01:001,781 MW1,953 MW
18 Sept, 02:001,766 MW1,813 MW
18 Sept, 03:001,763 MW1,850 MW
18 Sept, 04:001,819 MW1,955 MW
18 Sept, 05:001,919 MW2,109 MW
18 Sept, 06:002,018 MW2,182 MW
18 Sept, 07:002,073 MW2,148 MW
18 Sept, 08:002,109 MW2,046 MW
18 Sept, 09:002,130 MW1,997 MW
18 Sept, 10:002,124 MW1,986 MW
18 Sept, 11:002,104 MW1,972 MW
18 Sept, 12:002,092 MW1,976 MW
18 Sept, 13:002,079 MW1,998 MW
18 Sept, 14:002,115 MW2,022 MW
18 Sept, 15:002,173 MW2,046 MW
18 Sept, 16:002,235 MW2,052 MW
18 Sept, 17:002,195 MW2,062 MW
18 Sept, 18:002,192 MW2,062 MW
18 Sept, 19:002,181 MW2,045 MW
18 Sept, 20:002,115 MW1,959 MW
18 Sept, 21:002,009 MW1,848 MW
18 Sept, 22:001,902 MW1,750 MW
18 Sept, 23:001,799 MW1,693 MW
19 Sept, 00:001,717 MW1,745 MW
19 Sept, 01:001,688 MW1,871 MW
19 Sept, 02:001,649 MW1,761 MW
19 Sept, 03:001,641 MW1,753 MW
19 Sept, 04:001,668 MW1,811 MW
19 Sept, 05:001,715 MW1,906 MW
19 Sept, 06:001,766 MW1,996 MW
19 Sept, 07:001,851 MW2,059 MW
19 Sept, 08:001,894 MW2,058 MW
19 Sept, 09:001,913 MW2,036 MW
19 Sept, 10:001,927 MW2,034 MW
19 Sept, 11:001,955 MW2,038 MW
19 Sept, 12:001,979 MW2,041 MW
19 Sept, 13:002,018 MW2,043 MW
19 Sept, 14:002,087 MW2,065 MW
19 Sept, 15:002,148 MW2,091 MW
19 Sept, 16:002,214 MW2,109 MW
19 Sept, 17:002,229 MW2,125 MW
19 Sept, 18:002,210 MW2,128 MW
19 Sept, 19:002,165 MW2,065 MW
19 Sept, 20:002,068 MW1,936 MW
19 Sept, 21:001,937 MW1,773 MW
19 Sept, 22:001,808 MW1,641 MW
19 Sept, 23:001,717 MW1,547 MW
20 Sept, 00:001,642 MW1,628 MW
20 Sept, 01:001,594 MW1,808 MW
20 Sept, 02:001,578 MW1,667 MW
20 Sept, 03:001,562 MW1,674 MW
20 Sept, 04:001,586 MW1,742 MW
20 Sept, 05:001,635 MW1,851 MW
20 Sept, 06:001,684 MW1,947 MW
20 Sept, 07:001,735 MW2,019 MW
20 Sept, 08:001,784 MW2,017 MW
20 Sept, 09:001,815 MW1,992 MW
20 Sept, 10:001,860 MW1,976 MW
20 Sept, 11:001,923 MW1,961 MW
20 Sept, 12:001,977 MW1,957 MW
20 Sept, 13:002,071 MW1,972 MW
20 Sept, 14:002,181 MW2,007 MW
20 Sept, 15:002,289 MW2,039 MW
20 Sept, 16:002,359 MW2,065 MW
20 Sept, 17:002,399 MW2,092 MW
20 Sept, 18:002,268 MW2,103 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.