SolarpunkHomes
Sign inCall us · +44 7510 081687
Solar
Solar · Advice

Is a south, east-west or north-facing roof best for solar panels?

Short answer

Per panel, south is best. MCS tables put a 35° east or west roof at about 78–82% of south, south-east/south-west about 94%, and north only 51–59%. East-west splits output across the day and often fits more panels. Two east-west slopes can therefore beat one south roof in total output, though not per kWp (MCS, checked September 2026).

Last checked 24 September 2026 · 3 sources

In more detail

  • MCS azimuth: S=0°, SE/SW=45°, E/W=90°; table stops at 175° (nearest to due north).
  • Low pitches narrow the gap: at 10° E/W is ~92% and N ~83% of S; at 35° E/W ~80%, N ~55% (zone 1).
  • EST: east or west roofs get around 15-20% less than south; EST does not recommend north-facing roofs.
  • East arrays peak mid-morning, west arrays late afternoon/evening; this matches evening demand better than a single south array.

The facts, dated

  1. 01
    Zone 1, 35°: S / SE-SW / E-W / NE-NW / N Kk — 984 / 927 / 783 / 616 / 540 kWh/kWp/yr

    standard · England · checked 24 September 2026 · MCS

  2. 02
    Zone 1, 30°: N as % of S — 59 %

    standard · England · checked 24 September 2026 · MCS

  3. 03
    Zone 1, 20°: N as % of S — 70 %

    standard · England · checked 24 September 2026 · MCS

  4. 04
    EST: east/west roofs get 15-20% less than south — 15-20 %

    market_data · UK · checked 24 September 2026 · Energy Saving Trust

  5. 05
    PVGIS 2023 Portsmouth 35°: S 1101, E 872, W 873, N 583 — N=53% of S kWh/kWp

    market_data · England · checked 24 September 2026 · PVGIS (EU Joint Research Centre)

What we saw in the field

[QA review 2026-09-24] H-2 AGREES. I-3 CONTRADICTS per kWp (E/W 79% of S, zone 3 35 deg). I-4 AGREES at ~30 deg (zone 3 59%, zone 4 57%). | Earlier notes: Installer claim 'north-facing ~60% of south': AGREES with MCS at ~30° pitch (57-61% across zones). At 35° it is 51-59%, and at 20° 68-71%. Installer claim 'east-west can outperform south overall': per kWp it CONTRADICTS MCS/PVGIS (E/W ≈ 78-82% of S at 35°). It is PLAUSIBLE for total roof output when E-W allows about twice the panel count. Customer 1 profile (east ramps ~8am, fades early afternoon; west generates until ~8pm in August) is consistent with PVGIS hourly E/W shapes. Homeowner (SW England, 10 SW + 4 NE panels) says the NE panels only help in summer. PVGIS 2023 near Exeter for 1.6 kWp NE gives 189 kWh in June vs 12 kWh in December: AGREES.

Sources

Last checked: 24 September 2026