TPWR Demand Forecast Accuracy: Error, Bias and Worst Miss, 28 September to 28 October 2026

The day-ahead demand forecast for TPWR was off by 1.9% on average (mean absolute percentage error) over 719 hours from 28 September to 28 October 2026, and 96% of hours landed within 5% of the reading. Its bias was +1.3%: it ran high on average, an over forecast. The largest miss was 37 MW (7.6%) too high at 19 Oct 2026, 06:00 PDT (UTC-07:00). Dates and times are local (America/Los_Angeles).

Key Facts

The day-ahead demand forecast for TPWR was off by 1.9% on average (mean absolute percentage error) over 719 hours from 28 September to 28 October 2026, and 96% of hours landed within 5% of the reading. Its bias was +1.3%: it ran high on average, an over forecast. The largest miss was 37 MW (7.6%) too high at 19 Oct 2026, 06:00 PDT (UTC-07:00).
Across 53 US grids ranked by average error over their own latest 30 day windows, TPWR came 7 (1 is the smallest error).
On average the forecast differed from reported demand by 9 MW, against average demand of 462 MW.
The forecast was above reported demand in 74% of compared hours.

Forecast Error at a Glance

719 hours from 28 September to 28 October 2026

Average error1.9%

Bias+1.3%

Hours within 5%96%

Worst miss37 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+6 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 37 MW (7.6%) too high at 19 Oct 2026, 06:00 PDT (UTC-07:00): forecast 527 MW, reported 490 MW.

Source: U.S. Energy Information Administration (EIA). (US Government work, public domain) Data as of 2026-10-28. 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 28 Oct 2026, 04:00 PDT (UTC-07:00)

Hourly reported demand and the day-ahead forecast for TPWR over the last 7 days of the window, to 28 Oct 2026, 04:00 PDT (UTC-07:00). Gaps are hours with a missing, zero or implausible report.

Data to 2026-10-28

Show the data table (168 rows)

Local hour	Reported demand	Day-ahead forecast
21 Oct, 05:00	473 MW	475 MW
21 Oct, 06:00	539 MW	538 MW
21 Oct, 07:00	576 MW	571 MW
21 Oct, 08:00	594 MW	577 MW
21 Oct, 09:00	576 MW	560 MW
21 Oct, 10:00	559 MW	544 MW
21 Oct, 11:00	543 MW	531 MW
21 Oct, 12:00	521 MW	515 MW
21 Oct, 13:00	500 MW	504 MW
21 Oct, 14:00	489 MW	494 MW
21 Oct, 15:00	486 MW	489 MW
21 Oct, 16:00	492 MW	494 MW
21 Oct, 17:00	504 MW	507 MW
21 Oct, 18:00	529 MW	527 MW
21 Oct, 19:00	532 MW	535 MW
21 Oct, 20:00	518 MW	515 MW
21 Oct, 21:00	492 MW	489 MW
21 Oct, 22:00	453 MW	456 MW
21 Oct, 23:00	430 MW	427 MW
22 Oct, 00:00	404 MW	417 MW
22 Oct, 01:00	399 MW	406 MW
22 Oct, 02:00	394 MW	405 MW
22 Oct, 03:00	406 MW	410 MW
22 Oct, 04:00	423 MW	430 MW
22 Oct, 05:00	470 MW	475 MW
22 Oct, 06:00	527 MW	536 MW
22 Oct, 07:00	567 MW	572 MW
22 Oct, 08:00	569 MW	579 MW
22 Oct, 09:00	571 MW	569 MW
22 Oct, 10:00	557 MW	556 MW
22 Oct, 11:00	534 MW	545 MW
22 Oct, 12:00	513 MW	533 MW
22 Oct, 13:00	499 MW	523 MW
22 Oct, 14:00	495 MW	514 MW
22 Oct, 15:00	495 MW	512 MW
22 Oct, 16:00	499 MW	517 MW
22 Oct, 17:00	521 MW	530 MW
22 Oct, 18:00	551 MW	550 MW
22 Oct, 19:00	540 MW	554 MW
22 Oct, 20:00	524 MW	537 MW
22 Oct, 21:00	497 MW	509 MW
22 Oct, 22:00	451 MW	474 MW
22 Oct, 23:00	425 MW	448 MW
23 Oct, 00:00	405 MW	416 MW
23 Oct, 01:00	391 MW	406 MW
23 Oct, 02:00	390 MW	403 MW
23 Oct, 03:00	385 MW	407 MW
23 Oct, 04:00	406 MW	427 MW
23 Oct, 05:00	448 MW	471 MW
23 Oct, 06:00	501 MW	527 MW
23 Oct, 07:00	546 MW	565 MW
23 Oct, 08:00	554 MW	574 MW
23 Oct, 09:00	547 MW	566 MW
23 Oct, 10:00	542 MW	552 MW
23 Oct, 11:00	529 MW	542 MW
23 Oct, 12:00	520 MW	525 MW
23 Oct, 13:00	503 MW	514 MW
23 Oct, 14:00	493 MW	503 MW
23 Oct, 15:00	489 MW	502 MW
23 Oct, 16:00	501 MW	507 MW
23 Oct, 17:00	510 MW	524 MW
23 Oct, 18:00	528 MW	541 MW
23 Oct, 19:00	532 MW	542 MW
23 Oct, 20:00	527 MW	529 MW
23 Oct, 21:00	517 MW	510 MW
23 Oct, 22:00	490 MW	484 MW
23 Oct, 23:00	470 MW	465 MW
24 Oct, 00:00	458 MW	456 MW
24 Oct, 01:00	440 MW	443 MW
24 Oct, 02:00	443 MW	441 MW
24 Oct, 03:00	444 MW	443 MW
24 Oct, 04:00	453 MW	451 MW
24 Oct, 05:00	480 MW	469 MW
24 Oct, 06:00	512 MW	501 MW
24 Oct, 07:00	546 MW	537 MW
24 Oct, 08:00	568 MW	567 MW
24 Oct, 09:00	574 MW	579 MW
24 Oct, 10:00	557 MW	566 MW
24 Oct, 11:00	548 MW	548 MW
24 Oct, 12:00	533 MW	528 MW
24 Oct, 13:00	510 MW	509 MW
24 Oct, 14:00	491 MW	497 MW
24 Oct, 15:00	492 MW	494 MW
24 Oct, 16:00	489 MW	499 MW
24 Oct, 17:00	508 MW	513 MW
24 Oct, 18:00	524 MW	529 MW
24 Oct, 19:00	519 MW	526 MW
24 Oct, 20:00	505 MW	512 MW
24 Oct, 21:00	490 MW	495 MW
24 Oct, 22:00	467 MW	477 MW
24 Oct, 23:00	443 MW	461 MW
25 Oct, 00:00	423 MW	431 MW
25 Oct, 01:00	402 MW	419 MW
25 Oct, 02:00	398 MW	410 MW
25 Oct, 03:00	393 MW	408 MW
25 Oct, 04:00	397 MW	411 MW
25 Oct, 05:00	417 MW	424 MW
25 Oct, 06:00	440 MW	454 MW
25 Oct, 07:00	467 MW	482 MW
25 Oct, 08:00	497 MW	514 MW
25 Oct, 09:00	520 MW	535 MW
25 Oct, 10:00	532 MW	542 MW
25 Oct, 11:00	530 MW	540 MW
25 Oct, 12:00	534 MW	537 MW
25 Oct, 13:00	520 MW	528 MW
25 Oct, 14:00	511 MW	520 MW
25 Oct, 15:00	508 MW	522 MW
25 Oct, 16:00	511 MW	528 MW
25 Oct, 17:00	529 MW	543 MW
25 Oct, 18:00	544 MW	559 MW
25 Oct, 19:00	545 MW	559 MW
25 Oct, 20:00	525 MW	542 MW
25 Oct, 21:00	508 MW	517 MW
25 Oct, 22:00	470 MW	483 MW
25 Oct, 23:00	432 MW	452 MW
26 Oct, 00:00	415 MW	421 MW
26 Oct, 01:00	399 MW	406 MW
26 Oct, 02:00	392 MW	404 MW
26 Oct, 03:00	401 MW	407 MW
26 Oct, 04:00	413 MW	426 MW
26 Oct, 05:00	452 MW	472 MW
26 Oct, 06:00	509 MW	533 MW
26 Oct, 07:00	551 MW	564 MW
26 Oct, 08:00	550 MW	578 MW
26 Oct, 09:00	556 MW	571 MW
26 Oct, 10:00	548 MW	566 MW
26 Oct, 11:00	542 MW	561 MW
26 Oct, 12:00	529 MW	552 MW
26 Oct, 13:00	518 MW	540 MW
26 Oct, 14:00	512 MW	530 MW
26 Oct, 15:00	508 MW	531 MW
26 Oct, 16:00	528 MW	532 MW
26 Oct, 17:00	551 MW	551 MW
26 Oct, 18:00	571 MW	573 MW
26 Oct, 19:00	558 MW	572 MW
26 Oct, 20:00	541 MW	556 MW
26 Oct, 21:00	507 MW	523 MW
26 Oct, 22:00	468 MW	486 MW
26 Oct, 23:00	441 MW	456 MW
27 Oct, 00:00	414 MW	418 MW
27 Oct, 01:00	396 MW	402 MW
27 Oct, 02:00	390 MW	399 MW
27 Oct, 03:00	397 MW	401 MW
27 Oct, 04:00	407 MW	417 MW
27 Oct, 05:00	445 MW	454 MW
27 Oct, 06:00	507 MW	508 MW
27 Oct, 07:00	540 MW	540 MW
27 Oct, 08:00	547 MW	552 MW
27 Oct, 09:00	544 MW	556 MW
27 Oct, 10:00	552 MW	556 MW
27 Oct, 11:00	549 MW	553 MW
27 Oct, 12:00	540 MW	551 MW
27 Oct, 13:00	527 MW	542 MW
27 Oct, 14:00	530 MW	535 MW
27 Oct, 15:00	530 MW	537 MW
27 Oct, 16:00	538 MW	543 MW
27 Oct, 17:00	557 MW	562 MW
27 Oct, 18:00	598 MW	577 MW
27 Oct, 19:00	589 MW	577 MW
27 Oct, 20:00	573 MW	563 MW
27 Oct, 21:00	539 MW	533 MW
27 Oct, 22:00	502 MW	493 MW
27 Oct, 23:00	468 MW	465 MW
28 Oct, 00:00	448 MW	441 MW
28 Oct, 01:00	433 MW	426 MW
28 Oct, 02:00	422 MW	420 MW
28 Oct, 03:00	432 MW	424 MW
28 Oct, 04:00	444 MW	439 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.

Cite this page

APA 7

World Power Monitor. (2026). TPWR Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/tpwr/

Plain text

World Power Monitor. TPWR Demand Forecast Accuracy: Error, Bias and Worst Miss. Data as of 2026-10-28. Data from U.S. Energy Information Administration. https://worldpowermonitor.com/forecast-accuracy/tpwr/

BibTeX

@misc{wpm_forecast_accuracy_tpwr_2026,
  title = {{TPWR Demand Forecast Accuracy: Error, Bias and Worst Miss}},
  author = {{World Power Monitor}},
  year = {2026},
  note = {Data as of 2026-10-28. Data from U.S. Energy Information Administration.},
  url = {https://worldpowermonitor.com/forecast-accuracy/tpwr/}
}

Permalink: https://worldpowermonitor.com/forecast-accuracy/tpwr/

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TPWR Demand Forecast Accuracy: Error, Bias and Worst Miss, 28 September to 28 October 2026

Key Facts

Forecast Error at a Glance

Forecast and Reported Demand, Last 7 Days

Assumptions

Related