TL;DR
Face panels south where possible; aim for a fixed tilt around 30–40° in most of the UK.
Flat roofs: use mounting frames to reach ~30–35°; avoid ballasting that shades rows.
East/West roofs work well with split arrays; yield is ~10–20% lower than due south but spreads generation.
Prioritise shade avoidance and safe fixing over chasing small angle gains.
Why tilt matters
A good tilt aligns the panel with the sun’s average path, lifting annual yield and keeping rain run‑off effective. Small angle differences (e.g. 30° vs 35°) change yield far less than shading, orientation, or inverter limits.
The UK sweet spot (and East Sussex specifics)
Typical fixed tilt: 30–40° across England; 35° is a robust default.
Orientation: due south is best; south‑east/south‑west are close behind.
Latitude fine‑tuning gains are usually marginal for homes. Focus on shading and clean cable runs instead.
Pitched roofs
Most pitched roofs in the South East sit between 30–45°. If your roof pitch is within that range and faces south-ish, follow the roof—no special brackets needed.
If the pitch is shallow but shading is minimal, accept the pitch. The simplicity often beats small performance upsides from complex mounts.
Flat roofs
Use A‑frames or low‑tilt systems (aiming ~30–35°). Keep sufficient row spacing to prevent inter‑row shading, especially in winter.
Consider wind loading, ballast, and waterproofing. A structural check is essential.
East/West split arrays
Where south is unavailable, split strings (east and west). Morning + afternoon generation flattens the curve—handy for self‑consumption.
Expect slightly lower annual yield than south, but often better alignment with household demand.
Shade and obstructions
Chimneys, dormers, trees and neighbour roofs are bigger yield killers than a few degrees of tilt. If in doubt, move or remove a panel.
Use optimisers or parallel strings only when shade can’t be designed out.
Ground or wall mounting
Ground mounts: easy to set optimal tilt and keep panels clean; allow 30–35° and space for maintenance.
Wall mounts: choose a strong, south‑facing wall; ensure fixings and weatherproofed routing are sound.
Quick checks before you commit
Do I have clear southern sky for most of the day?
Any seasonal shade (winter sun is low)?
Can mounting and cable routes be kept simple and secure?
Bottom line
Pick a sensible fixed angle (~35°), avoid shade, keep runs tidy, and match array layout to your roof. That combination outperforms micro‑optimising tilt in almost every home install.
