Short answer
South brings the highest saving, even without net metering. East-west produces 17% less in our model, but you use more of it yourself (35% against 29%). That makes the gap in savings smaller: 6%. If you only have an east and a west side, solar panels are still a good idea.
Production and saving by orientation
10 panels at the same price (€3,800), 3,500 kWh of consumption and a roof pitch of 35 degrees.
| Orientation | Production a year | Used directly | Saving a year | Payback period | Net over the lifetime |
|---|---|---|---|---|---|
| South | 3,806 kWh | 29% | €428 | 9.3 years | €4,622 |
| South-east or south-west | 3,616 kWh | 30% | €415 | 9.6 years | €4,340 |
| East and west | 3,159 kWh | 35% | €400 | 9.9 years | €4,011 |
| East or west | 3,159 kWh | 33% | €390 | 10.2 years | €3,771 |
East-west spreads production over the morning and late afternoon, when you have breakfast, cook and come home. A south-facing panel peaks around noon, when most people are out. Without net metering, power you use yourself is worth €0.30 per kWh and exported power only €0.035. That is why the lower self-consumption of south-facing panels weighs more than it used to.
Does your consumption matter?
| Consumption | South | East-west | Difference |
|---|---|---|---|
| 2,500 kWh | €365 | €340 | 7% |
| 3,500 kWh | €428 | €400 | 6% |
| 6,000 kWh | €551 | €517 | 6% |
The higher your consumption, the more you use yourself from either orientation. South stays ahead.
Flat roof: east-west often fits more panels
On a flat roof, south-facing panels stand in rows with space between them so they do not shade each other. In an east-west layout they lean against each other like a small roof, and more of them fit. According to Milieu Centraal they yield about 10 percent less per panel, but you can fit more. If, for example, 12 instead of 10 panels fit on your roof (at the same price per layout), east-west saves €439 a year, against €428 facing south. So ask the installer about both layouts and enter the quotes in the calculator.
Compare orientations for your home →
Sources
- Milieu Centraal, Solar panels: how suitable is your roof? (in Dutch). Yield per orientation and pitch (south-west 5% and west 25% below south at 45 degrees; east-west spreads production over the day; on a flat roof east-west yields about 10% less per panel but more panels fit) and 0% VAT on solar panels on homes since 1 January 2023.
- Milieu Centraal, Cost and yield of solar panels (in Dutch). Price and yield of 6, 8 and 10 panels of 435 Wp (€2,500 / 2,300 kWh, €3,200 / 3,000 kWh, €3,800 / 3,800 kWh), about 30% direct self-consumption, a 25-year lifetime and about 600 kg CO2 saved a year with 8 panels after production.
- KNMI, Climate normals for De Bilt 1991–2020. Average global radiation per month (364.8 kJ/cm² a year, converted 1,013 kWh/m²) and average temperature per month.