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

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

The day-ahead demand forecast for FPC was off by 23.3% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 0% of hours landed within 5% of the reading. Its bias was -23.3%: it ran low on average, an under forecast. The largest miss was 3,369 MW (29.3%) too low at 26 Aug 2026, 16:00 EDT (UTC-04:00). Dates and times are local (America/New_York).

Key Facts

  • The day-ahead demand forecast for FPC was off by 23.3% on average (mean absolute percentage error) over 719 hours from 21 August to 20 September 2026, and 0% of hours landed within 5% of the reading. Its bias was -23.3%: it ran low on average, an under forecast. The largest miss was 3,369 MW (29.3%) too low at 26 Aug 2026, 16:00 EDT (UTC-04:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, FPC came 50 (1 is the smallest error).
  • On average the forecast differed from reported demand by 1,872 MW, against average demand of 7,951 MW.
  • The forecast was above reported demand in 0% of compared hours.

Forecast Error at a Glance

719 hours from 21 August to 20 September 2026
Average error23.3%
Bias-23.3%
Hours within 5%0%
Worst miss3,369 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-1,872 MW per hour on average): the forecast ran low on average, an under forecast. The worst miss was 3,369 MW (29.3%) too low at 26 Aug 2026, 16:00 EDT (UTC-04:00): forecast 8,139 MW, reported 11,508 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, 21:00 EDT (UTC-04:00)
FPC day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for FPC over the last 7 days of the window, to 20 Sept 2026, 21:00 EDT (UTC-04:00). Gaps are hours with a missing, zero or implausible report. 0 3,000 6,000 9,000 12,000 13 Sept, 22:0014 Sept, 22:0015 Sept, 22:0016 Sept, 22:0017 Sept, 22:0018 Sept, 22:0019 Sept, 22:00
Hourly reported demand and the day-ahead forecast for FPC over the last 7 days of the window, to 20 Sept 2026, 21:00 EDT (UTC-04:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-09-20
FPC day-ahead demand forecast and reported demand by hour
Local hourReported demandDay-ahead forecast
13 Sept, 22:008,189 MW6,517 MW
13 Sept, 23:007,419 MW5,927 MW
14 Sept, 00:006,866 MW4,942 MW
14 Sept, 01:006,421 MW4,608 MW
14 Sept, 02:006,095 MW4,369 MW
14 Sept, 03:005,937 MW4,259 MW
14 Sept, 04:005,891 MW4,276 MW
14 Sept, 05:006,053 MW4,474 MW
14 Sept, 06:006,398 MW4,752 MW
14 Sept, 07:006,552 MW4,972 MW
14 Sept, 08:006,918 MW5,211 MW
14 Sept, 09:007,555 MW5,591 MW
14 Sept, 10:008,374 MW6,069 MW
14 Sept, 11:009,193 MW6,624 MW
14 Sept, 12:009,966 MW7,158 MW
14 Sept, 13:0010,558 MW7,549 MW
14 Sept, 14:0010,958 MW7,849 MW
14 Sept, 15:0011,230 MW8,034 MW
14 Sept, 16:0011,262 MW8,130 MW
14 Sept, 17:0011,103 MW8,049 MW
14 Sept, 18:0010,581 MW7,831 MW
14 Sept, 19:0010,194 MW7,584 MW
14 Sept, 20:009,772 MW7,286 MW
14 Sept, 21:009,111 MW6,817 MW
14 Sept, 22:008,318 MW6,251 MW
14 Sept, 23:007,558 MW5,695 MW
15 Sept, 00:006,959 MW5,344 MW
15 Sept, 01:006,503 MW4,966 MW
15 Sept, 02:006,180 MW4,686 MW
15 Sept, 03:005,983 MW4,533 MW
15 Sept, 04:005,919 MW4,507 MW
15 Sept, 05:006,100 MW4,665 MW
15 Sept, 06:006,453 MW4,897 MW
15 Sept, 07:006,609 MW5,082 MW
15 Sept, 08:006,950 MW5,284 MW
15 Sept, 09:007,546 MW5,620 MW
15 Sept, 10:008,298 MW6,063 MW
15 Sept, 11:009,243 MW6,572 MW
15 Sept, 12:0010,041 MW7,090 MW
15 Sept, 13:0010,347 MW7,477 MW
15 Sept, 14:0010,324 MW7,734 MW
15 Sept, 15:0010,142 MW7,858 MW
15 Sept, 16:0010,160 MW7,910 MW
15 Sept, 17:0010,136 MW7,806 MW
15 Sept, 18:009,937 MW7,578 MW
15 Sept, 19:009,668 MW7,311 MW
15 Sept, 20:009,370 MW6,998 MW
15 Sept, 21:008,842 MW6,548 MW
15 Sept, 22:008,103 MW6,008 MW
15 Sept, 23:007,389 MW5,520 MW
16 Sept, 00:006,806 MW5,159 MW
16 Sept, 01:006,367 MW4,838 MW
16 Sept, 02:006,094 MW4,594 MW
16 Sept, 03:005,946 MW4,456 MW
16 Sept, 04:005,951 MW4,447 MW
16 Sept, 05:006,160 MW4,607 MW
16 Sept, 06:006,544 MW4,834 MW
16 Sept, 07:006,660 MW5,006 MW
16 Sept, 08:006,883 MW5,193 MW
16 Sept, 09:007,379 MW5,486 MW
16 Sept, 10:007,933 MW5,861 MW
16 Sept, 11:008,487 MW6,269 MW
16 Sept, 12:009,084 MW6,676 MW
16 Sept, 13:009,623 MW6,987 MW
16 Sept, 14:0010,003 MW7,235 MW
16 Sept, 15:0010,383 MW7,463 MW
16 Sept, 16:0010,633 MW7,646 MW
16 Sept, 17:0010,725 MW7,649 MW
16 Sept, 18:0010,438 MW7,484 MW
16 Sept, 19:009,959 MW7,249 MW
16 Sept, 20:009,528 MW6,944 MW
16 Sept, 21:008,875 MW6,471 MW
16 Sept, 22:008,105 MW5,919 MW
16 Sept, 23:007,260 MW5,388 MW
17 Sept, 00:006,656 MW4,808 MW
17 Sept, 01:006,176 MW4,475 MW
17 Sept, 02:005,877 MW4,243 MW
17 Sept, 03:005,673 MW4,114 MW
17 Sept, 04:005,662 MW4,124 MW
17 Sept, 05:005,875 MW4,300 MW
17 Sept, 06:006,296 MW4,554 MW
17 Sept, 07:006,440 MW4,738 MW
17 Sept, 08:006,631 MW4,937 MW
17 Sept, 09:007,051 MW5,237 MW
17 Sept, 10:007,608 MW5,641 MW
17 Sept, 11:008,245 MW6,094 MW
17 Sept, 12:008,885 MW6,549 MW
17 Sept, 13:009,426 MW6,892 MW
17 Sept, 14:009,714 MW7,151 MW
17 Sept, 15:009,993 MW7,342 MW
17 Sept, 16:0010,365 MW7,498 MW
17 Sept, 17:0010,450 MW7,387 MW
17 Sept, 18:0010,185 MW7,168 MW
17 Sept, 19:009,703 MW6,967 MW
17 Sept, 20:009,284 MW6,787 MW
17 Sept, 21:008,624 MW6,348 MW
17 Sept, 22:007,846 MW5,823 MW
17 Sept, 23:007,033 MW5,274 MW
18 Sept, 00:006,476 MW4,885 MW
18 Sept, 01:005,968 MW4,537 MW
18 Sept, 02:005,646 MW4,290 MW
18 Sept, 03:005,519 MW4,143 MW
18 Sept, 04:005,450 MW4,132 MW
18 Sept, 05:005,633 MW4,284 MW
18 Sept, 06:005,964 MW4,517 MW
18 Sept, 07:006,171 MW4,693 MW
18 Sept, 08:006,488 MW4,906 MW
18 Sept, 09:007,085 MW5,233 MW
18 Sept, 10:007,809 MW5,647 MW
18 Sept, 11:008,602 MW6,119 MW
18 Sept, 12:009,301 MW6,647 MW
18 Sept, 13:009,819 MW7,104 MW
18 Sept, 14:0010,129 MW7,462 MW
18 Sept, 15:0010,343 MW7,700 MW
18 Sept, 16:0010,620 MW7,861 MW
18 Sept, 17:0010,447 MW7,826 MW
18 Sept, 18:009,881 MW7,593 MW
18 Sept, 19:009,343 MW7,253 MW
18 Sept, 20:008,966 MW6,926 MW
18 Sept, 21:008,393 MW6,511 MW
18 Sept, 22:007,784 MW6,039 MW
18 Sept, 23:007,104 MW5,525 MW
19 Sept, 00:006,555 MW5,092 MW
19 Sept, 01:006,079 MW4,719 MW
19 Sept, 02:005,722 MW4,428 MW
19 Sept, 03:005,441 MW4,243 MW
19 Sept, 04:005,322 MW4,153 MW
19 Sept, 05:005,328 MW4,144 MW
19 Sept, 06:005,379 MW4,196 MW
19 Sept, 07:005,515 MW4,330 MW
19 Sept, 08:006,048 MW4,653 MW
19 Sept, 09:006,760 MW5,110 MW
19 Sept, 10:007,502 MW5,605 MW
19 Sept, 11:008,265 MW6,107 MW
19 Sept, 12:009,023 MW6,561 MW
19 Sept, 13:009,580 MW6,911 MW
19 Sept, 14:009,738 MW7,141 MW
19 Sept, 15:009,746 MW7,255 MW
19 Sept, 16:009,478 MW7,291 MW
19 Sept, 17:009,283 MW7,180 MW
19 Sept, 18:009,019 MW6,920 MW
19 Sept, 19:008,701 MW6,639 MW
19 Sept, 20:008,423 MW6,380 MW
19 Sept, 21:007,967 MW6,041 MW
19 Sept, 22:007,390 MW5,635 MW
19 Sept, 23:006,781 MW5,201 MW
20 Sept, 00:006,323 MW4,860 MW
20 Sept, 01:005,794 MW4,520 MW
20 Sept, 02:005,464 MW4,255 MW
20 Sept, 03:005,242 MW4,080 MW
20 Sept, 04:005,095 MW3,997 MW
20 Sept, 05:005,060 MW3,980 MW
20 Sept, 06:005,169 MW4,014 MW
20 Sept, 07:005,298 MW4,133 MW
20 Sept, 08:005,792 MW4,459 MW
20 Sept, 09:006,496 MW4,928 MW
20 Sept, 10:007,186 MW5,439 MW
20 Sept, 11:007,926 MW5,940 MW
20 Sept, 12:008,569 MW6,433 MW
20 Sept, 13:008,991 MW6,850 MW
20 Sept, 14:009,153 MW7,149 MW
20 Sept, 15:009,244 MW7,257 MW
20 Sept, 16:009,209 MW7,286 MW
20 Sept, 17:009,037 MW7,152 MW
20 Sept, 18:008,591 MW6,884 MW
20 Sept, 19:008,285 MW6,583 MW
20 Sept, 20:008,056 MW6,321 MW
20 Sept, 21:007,559 MW5,991 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.