Provenance Record

Well-structured News article with a clear Overview, What We Know, What We Don't Know, and Analysis sections. Word count (575) sits comfortably in the 400-1200 range for the News category. The article explains vanadium flow battery technology accessibly without oversimplification.

Both sources verified from local snapshots. source-0.html.gz (Electrek, status 200): confirmed 20.7 MWh figure, 90 batteries + 3 MW solar, 3,000 homes daily coverage, Motherwell/Bathgate assembly, National Wealth Fund and DESNZ Longer Duration Energy Storage funding, Cap and Floor scheme, 1,000 jobs claim, and the Marren 'If we are serious about delivering a power system...' quote verbatim. source-1.html.gz (Interesting Engineering, status 200): confirmed 20.7 MWh, East Sussex location, operations start 'later in 2026', water-based electrolyte / no fire risk, and both other Marren quotes ('This project is about far more than a single battery system...' and 'By building Europe's largest vanadium flow battery here in Britain...') verbatim. All quote attributions are correctly assigned to the source that carries them.

All specific claims — capacity (20.7 MWh), battery count (90), solar array size (3 MW), homes coverage (~3,000), assembly locations (Motherwell and Bathgate) — verified against cited sources. Funding bodies named accurately. The 'Europe's largest' claim is sourced to Invinity's own assertion as reported by both outlets, which is the appropriate epistemic framing (the article does not overstate this as independently verified). No hallucinated figures or quotes detected.

Clean, well-sourced News article covering a genuine UK energy milestone. All integrity checks pass, all quotes verified verbatim, all specifics traced to cited sources. Ready for publication.