Quartz Solar goes live at NESO and may avoid £30m a year in costs

Open Climate Fix's machine-learning solar forecast is live in NESO's control room; OCF claims at least £30m a year in avoided imbalance costs, a figure NESO's quoted statement does not give.

AI system

System

Quartz Solar (Open Climate Fix machine-learning solar PV forecast, formerly PVNet)

Model

PVNet.

Release

Exact release not established.

Application developer

Open Climate Fix

Role

The model forecast electricity generation from solar panels.

Configuration

Not assessed

Inputs and outputs

Not assessed

Autonomy

Not assessed

Workflow

Satellite imagery, numerical weather data and historical generation data for a national PV fleet. A system operator innovation program (NIA) that funded testing before operational integration. A forecast refresh cycle faster than the operator's existing six-hourly weather updates.

Human oversight

Not assessed

Relation to AI

The machine-learning forecast is the system in use. But both figures (£30m, 300,000 t CO2) come from Open Climate Fix's announcement reproduced by trade press. NESO's own quoted statement confirms deployment and 36-hour accuracy only. No NESO-authored page or regulator document with a savings figure was found.

AI contribution

Not assessed

Benefits

Outcome identifiers

Not assessed

Benefit

at least £30m a year in avoided imbalance costs

Category

Improved Organizational Efficiency

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

at least £30m a year in avoided imbalance costs

Comparison

NESO's solar forecasts before Quartz Solar was adopted

Results

Reference: forecasting errors before adoption (not quantified). Result: halved forecasting errors.

Additional value from AI

Not assessed

Limitations

Not assessed

Denominators

Not assessed

Materials for replication

Not assessed

Money

Kind of value

imbalance cost avoided per year

Amount

Estimate: GBP 30 million

Currency and prices

GBP, stated in the source. Nominal source amount; price year not separately stated.

Period and unit

Annualized estimate published November 6, 2025; no completed measurement year is specified. Annual electricity imbalance costs.

Realization

Annualized estimate.

Recipients and payers

Recipient: Great Britain’s electricity system and its cost bearers. Payer: Electricity balancing and imbalance settlement participants.

Gross or net

Estimated annual gross operating-cost avoidance, without implementation and ongoing service costs.

Included costs

Not assessed

Comparison

Previous NESO forecasting tools; the monetary calculation is not provided.

Method

Not assessed

Return and payback

Not assessed

People and places

Participants

Developer: Open Climate Fix. Operator: National Energy System Operator (NESO).

Jurisdictions

Benefit: United Kingdom. Developer: United Kingdom. Operator: United Kingdom.

Ownership and control

Not assessed

Dependencies

Not assessed

Cross-border connections

Not assessed

Geopolitical implications

Not assessed

Follow-up

Conditions for replication

Access to live satellite and generation data. An operator willing to integrate a third-party forecast into reserve setting. Independent measurement of imbalance-cost changes, which is absent here.

Replication attempts

Not assessed

Later findings

No development dated after the November 2025 go-live reports was found.

Availability

Not assessed

Institutional decision

Not assessed

Grounds

Not assessed

Action and result

Not assessed

Success criterion

Not assessed

Evidence

Source numbers

AIBD-0163-source-0001–0004

Citations

Numbered references below.

Language

Not assessed

Source relationships

Independent, Developer

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: NESO confirms operational use and 36-hour forecasting. The £30m saving is OCF's estimate, so no measured outcome is documented. Society: The 300,000-tonne CO2 figure is the maker's estimate. No independent measurement 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. Electricity system operation and balancing.

Purpose

Quartz Solar is built to forecast national and regional solar PV output for grid balancing. Operational use for reserve setting is the intended purpose.

Dates

Date basis unassessed: 2025 (precision unassessed). Updated: 21 October 2026.

Stage

Not assessed

Version

SHA-256: 762f56e9d617…

References

Other identifiers

Not assessed

Category mappings

Not assessed

Brief

Not assessed

Revisions

6 revisions. Latest: 21 October 2026.

Sources

  1. News report Independent author

    Tim McManan-Smith, 'National Energy System Operator adopts AI solar forecasting to save £30m', The Energyst, 6 November 2025

  2. News report Independent author

    Matthew Lynas, 'AI powered solar forecasting helps UK grid operator reduce balancing costs', pv magazine, 7 November 2025

  3. Press release Developer

    Open Climate Fix website, product spotlight, GB National Solar Forecast