Solar Panels on a North-Facing Roof: Honest Assessment

4kW system comparison:

| Direction | Annual Gen | Annual Savings | Cost | Payback | 25yr Net | |-----------|-----------|---------------|------|---------|----------| | South | 4,000 kWh | £700–£900 | £6,750 | 8–10 yrs | £10,750–£15,750 | | South-East | 3,800 kWh | £660–£850 | £6,750 | 8–11 yrs | £9,750–£14,500 | | East/West | 3,300 kWh | £570–£740 | £6,750 | 9–12 yrs | £7,500–£11,750 | | North | 2,300 kWh | £400–£520 | £6,750 | 13–17 yrs | £3,250–£6,250 |

The north-facing system still generates a positive return over 25 years — but the return is roughly 50–60% less than south-facing. The payback period pushes uncomfortably close to the inverter replacement point (10–15 years), meaning you may need to spend another £800–£1,500 before the original system has fully paid for itself.

Source: PVGIS UK orientation data; Ofgem Q1 2026 price cap.

Before accepting north-facing panels, consider these alternatives:

1. Ground-mounted panels: If you have a garden, ground-mounted panels can be angled optimally toward the south. Cost premium: 10–15% more than roof-mounted, but you get 100% output.

2. Solar carport/garage: If you have a detached garage or carport with a different orientation, these may offer better panel positioning.

3. Invest in energy efficiency instead: The £6,750 you would spend on north-facing solar might deliver better returns if spent on: - Loft insulation (£300–£600, saves £100–£200/year on heating) - Cavity wall insulation (£500–£1,500, saves £200–£400/year) - Double glazing upgrade (£3,000–£7,000, saves £100–£200/year) - LED lighting throughout (£100–£300, saves £50–£100/year)

4. Wait for a better option: If you plan to move within 5–10 years, you may be better served by investing in a south-facing system at your next property.

Source: Energy Saving Trust; MCS installer guidance.

North-east and north-west are slightly better than due north:

• North-east: 60–65% of south-facing output. Captures some morning sun.
• North-west: 60–65% of south-facing output. Captures some afternoon sun.
• Due north: 55–60% of south-facing output. Relies almost entirely on diffused light.

The difference between NE/NW and due north is small (about 5 percentage points). None of these directions are ideal, but NE/NW are marginally better.

Our honest recommendation: If your only option is a north, north-east, or north-west facing roof, the money is usually better spent on other energy efficiency improvements — unless you have very high electricity consumption or are committed to renewable energy regardless of payback period.

Source: PVGIS UK irradiance data by orientation.