NCAR's DICast cuts Xcel's wind forecast error to 10.8%

NCAR's adaptive forecast-blending system (DICast), used by Xcel Energy since 2009, cut mean wind forecast error from about 18% to 10.8% by 2014; Xcel estimated US$49m saved (IEEE Spectrum 2015).

AI system

System

NCAR wind power forecasting system with the DICast adaptive forecast blending engine

Model

Not assessed

Release

Not assessed

Application developer

National Center for Atmospheric Research (Research Applications Laboratory)

Role

Not assessed

Configuration

Not assessed

Inputs and outputs

Not assessed

Autonomy

Not assessed

Workflow

Multiple numerical weather models blended with an adaptive statistical layer trained on each wind farm's history. Forecast updates every 15 minutes feeding unit-commitment decisions. A utility with large wind capacity and dispatchable coal and gas units to decommit.

Human oversight

Not assessed

Relation to AI

The forecasting system's contribution to savings is Xcel's own estimate relayed by NCAR authors and reporters. The AI character of the system rests on UCAR's reference to artificial-intelligence research and DICast's adaptive bias correction, not on an explicit machine-learning description. So both the AI status and the causal share are unverified.

AI contribution

Not assessed

Benefits

Outcome identifiers

Not assessed

Benefit

cut mean wind forecast error from about 18% to 10.8% by 2014; Xcel estimated US$49m saved

Category

Improved Task Accuracy

Status

Not assessed

Beneficiary groups

Organizations. Society.

Beneficiaries

Not assessed

Reach

Not assessed

Distribution and access

Not assessed

Duration

Not assessed

Expected?

Yes

Costs and harms

Not assessed

Measurement

Studies

Not assessed

Study design

Not assessed

Measurement

Not assessed

Setting and sample

Not assessed

Measures

cut mean wind forecast error from about 18% to 10.8% by 2014; Xcel estimated US$49m saved

Comparison

Xcel's wind forecasts in 2008, before NCAR's system

Results

Reference: about 18 percent for 18 to 42 hours ahead. Result: 10.8 percent.

Additional value from AI

Not assessed

Limitations

Not assessed

Denominators

Not assessed

Materials for replication

Not assessed

Money

Kind of value

saved through forecasting improvements, cumulative to 2015

Amount

Estimate: US $49 million

Currency and prices

Not assessed

Period and unit

Not assessed

Realization

Not assessed

Recipients and payers

Xcel Energy customers

Gross or net

Not assessed

Included costs

Not assessed

Comparison

Not assessed

Method

Not assessed

Return and payback

Not assessed

People and places

Participants

Developer: National Center for Atmospheric Research (Research Applications Laboratory). Operator: Xcel Energy.

Jurisdictions

Benefit: United States. Developer: United States. Operator: United States.

Ownership and control

Not assessed

Dependencies

Not assessed

Cross-border connections

Not assessed

Geopolitical implications

Not assessed

Follow-up

Conditions for replication

Continuous observed generation data for bias correction. Operators who act on forecast confidence bands. An independent accounting of avoided production costs, absent here.

Replication attempts

Not assessed

Later findings

4 December 2017. By 2017 Xcel was still relying on the NCAR forecasts, which Haupt said saved about $10 million a year in production costs, while it planned coal retirements and more wind.

Availability

Not assessed

Institutional decision

Not assessed

Grounds

Not assessed

Action and result

Not assessed

Success criterion

Not assessed

Evidence

Source numbers

AIBD-0168-source-0001–0004

Citations

Numbered references below.

Language

Not assessed

Source relationships

Developer, Independent

Original evidence

Not assessed

Access and versions

Not assessed

Supported findings

Not assessed

Evidence strength

Not assessed

Missing evidence

Not assessed

Grades

Assessed benefits

Organizations. Society.

Depth

Not assessed

Reasons

Organizations: Xcel's US$49 million estimate and the error reduction to 10.8% are reported by the makers and the press without independent measurement. Society: Ratepayer savings and coal-unit decommitment are reported as estimates. No audited figure is documented.

Observed or intended

Not assessed

Rubric

Not assessed

Assessor and date

Not assessed

Alternative assessments

Not assessed

Fill

Independently reported

Entry details

Kind

Not assessed

Field

Energy. Utility wind generation forecasting.

Purpose

The system was built to forecast wind generation for Xcel's unit-commitment and trading decisions. The cost savings are its intended use.

Dates

Date basis unassessed: 2015 (precision unassessed). Updated: 21 October 2026.

Stage

Not assessed

Version

SHA-256: 92c4d2686043…

References

Other identifiers

Not assessed

Category mappings

Not assessed

Brief

Not assessed

Revisions

5 revisions. Latest: 21 October 2026.

Sources

  1. News report Developer

    Sue Ellen Haupt and William P. Mahoney, 'Taming Wind Power With Better Forecasts', IEEE Spectrum, 22 October 2015

  2. News report Independent author

    John Fialka and Benjamin Storrow, 'Xcel learns to forecast wind, then shuts coal plants', E&E News, 4 December 2017

  3. Press release Developer

    UCAR/NCAR AtmosNews, 'Wind power wisdom', 7 February 2012