2 modelling_e2e properties failed with KeyError: 'maxArrayPanelsCount'.
Google returns a `solarPotential` block with no array-level sizing fields
(`maxArrayPanelsCount` / `panelCapacityWatts`) for buildings with no usable
solar estimate. `SolarPotential.from_building_insights` hard-indexed those keys
and crashed the whole property.
Fix: the projection now returns Optional and yields None when those fields are
absent — the established "no solar potential" outcome (the orchestrator and
recommendation path already type it Optional and skip solar on None). Existing
callers (`_solar_potential_for`, harness) already assign to Optional.
Regression test + `assert is not None` narrowing on the valid-fixture tests.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Slice 6 of the Solar PV Recommendation Generator (ADR-0026). `recommend_solar`
emits one "Solar PV" Recommendation of up to five conservatively-sized configs
× {no battery, battery} = ≤10 competing Options (a free Optimiser candidate).
Each Option folds a SolarOverlay built from the chosen config: one
PhotovoltaicArray per non-north segment (peak_power = panels × panelCapacityW /
1000; orientation/pitch from geometry; generation-calibrated overshading),
is_dwelling_export_capable set True absolutely, a diverter when the dwelling
has a cylinder (None for a combi), a 5 kWh battery for the battery variant, and
the per-config composite cost from Products.solar_bundle_cost.
Eligibility = house/bungalow ∧ not listed/heritage (blocks_internal, the same
gate as ASHP — a conservation area does NOT block PV) ∧ no existing PV ∧ a
feasible SolarPotential. Flats and existing-PV top-up are deferred.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
