Define the study
Set inputs, scenario assumptions, configuration and module versions before launching a run.
VALUE / SYSTEM EVOLUTION
Power systems, evolving.
Connect half-hourly operation with annual investment decisions.
Operation informs investment.
VALUE connects operational simulation with investment decisions across years. A study describes the scenario; a run records one execution and its results.
The research boundary is explicit: technologies, demand, network representation and investment assumptions belong to a particular study configuration.
VALUE / SYSTEM LOGICConcept diagram
A cycle across three stages
Simulate operation
Represent half-hourly dispatch, storage operation and settlement within the configured network boundary.
Update the system
Use operational outcomes in annual investment decisions, then carry the changed assets into the next year.
Configurations are part of the method
| Configuration | What it represents | Scope and next steps |
|---|---|---|
| National baseline | System-level operation and investment with a national boundary. | Engineering repeatability applies to the tested configuration; global optimality requires separate analysis. |
| GB zonal study | A fixed, lossless transport representation: 23 zones, 22 corridors and two boundary constraints. | This configuration uses a lossless zonal transport model. |
Two methodology profiles
The methodology on this website describes the VALUE model as published: the corrected methodology, which new Studies and Runs use by default. A doctoral reproduction profile is kept for comparison with the thesis-era settings.
| Profile | Method | Scope |
|---|---|---|
| Corrected methodology (default) | The VALUE model that the methodology describes, and the default for new Studies and Runs. Besides the corrections shared with the doctoral profile, it uses storage bids at cycle wear with uniform-price settlement, interconnector imports in the day-ahead clearing, nuclear in service from the start of each year, down regulation that weighs restart cost against the fuel, carbon and variable cost avoided, literature wind and solar losses with plane-of-array solar, station nuclear and DUKES hydro availability, storage headroom from the post-charge surplus with one cap per battery type, declared data reading, and network economics. | A different method from the doctoral reproduction profile; compare the two as different methods. Wind and solar capacity factors are disclosed next to DUKES, not calibrated to them. |
| Doctoral reproduction (as implemented in VALUE 0.6.0-alpha.2) — not an exact reproduction of the 2026-07-18 retained trajectory | A compatibility profile that keeps the thesis-era settings with the retained implementation, such as wind curtailed first at zero cost, no wind and solar loss factors, no availability derating of nuclear and hydro, and the original data readings. The corrections shared with the default profile apply to it: interconnector series on the run clock, three GBP1 reading errors, declared-column reading, thermal investment net of running cost, a value of lost load of £17,000/MWh, down regulation taken once, one storage position per period, must-run nuclear surplus counted once, stress events and accounting corrections. Thesis-lineage modules and data packs only; refuses enabled external code. | Annual results appear on result pages only when every raw invariant passed; otherwise read them in Inspect or the ledger files. Not an exact reproduction of the thesis results. |
Versioned methodology
Read the audited equations, numerical parameters, pseudocode and initial dataset identities. The complete methodology distinguishes implementation, tested examples and remaining reproducibility gaps.
Read the full methodology