What's allowed on a listed building
Listed Building Consent is mandatory before any solar installation. Most local planning authorities (Birmingham, Lichfield, Stratford-on-Avon, Worcester) will consider solar on (a) rear/non-public-facing elevations, (b) outbuildings within the curtilage, (c) ground-mount sites screened from public view. Visible front-facing installs are usually refused.
Solar tiles as a heritage solution
Slate-matched and clay-matched solar tiles (GB-Sol, Marley SolarTile, Tesla Solar Roof) are virtually invisible from ground level — significantly more conservation-officer-friendly than conventional panels. More expensive (~£12,000-£18,000 for a typical 3-4kW installation) but often the only route to consent on a sensitive listed roof.