How nuclear generation dispatch and availability patterns are modelled
Nuclear power is modelled as a baseload, seasonally-adjusted generation source. Availability patterns reflect real-world operational constraints, maintenance schedules, and market dynamics.
France is treated as a special case — part of its nuclear fleet is modelled as price-responsive rather than pure baseload.
Nuclear availability is calculated from historical data
Nuclear availability is modelled using historical outage patterns derived from actual generation and capacity data. The model uses data from September 2023 to September 2024 to establish baseline availability patterns.
Historical nuclear generation is combined with available capacity data to calculate load factors that reflect both planned and unplanned outages. These patterns are decomposed into three seasonal components:
| Component | What it captures |
|---|---|
| Hour-of-day effects | Any intraday load-following behaviour |
| Day-of-week patterns | Weekly operational cycles |
| Rolling seasonal patterns | Longer-term maintenance cycles and seasonal variations (28-day rolling window) |
France’s nuclear fleet responds to price signals
The French nuclear fleet has unique operational flexibility. Unlike other countries where nuclear runs as pure baseload, French nuclear demonstrates price-responsive behaviour.
This is modelled by:
- Calculating the proportion of capacity that shows price-responsive behaviour
- Reducing baseline French nuclear capacity by this proportion
- Creating dispatchable nuclear units with supply curves based on historical price response
Retirement and policy schedules vary by country
Nuclear capacity follows country-specific retirement and policy schedules:
| Country | Approach |
|---|---|
| Germany | Zero capacity from April 2023 onwards (nuclear phase-out complete) |
| Spain | Based on the “7o. Plan General de Residuos Radioactivos” (PGRR, 2023) nuclear phase-out plan |
| France | Capacity evolution based on RTE’s “Futurs Énergétiques 2050” NO3 scenario |
| Other countries | Based on announced plant closures and life extensions |