Kenya receives strong solar resource across most of the country. The table below shows average peak sun hours (PSH) and global horizontal irradiation for representative regions. Use these values for initial system sizing; site-specific measurements give the best accuracy.
| Region / town | Peak sun hours/day | Annual kWh/m² |
|---|---|---|
| Nairobi | 5.5 – 6.0 | 1,900 – 2,100 |
| Mombasa | 5.5 – 6.0 | 1,950 – 2,150 |
| Kisumu | 5.0 – 5.5 | 1,800 – 2,000 |
| Nakuru | 5.5 – 6.0 | 1,950 – 2,150 |
| Eldoret | 5.0 – 5.5 | 1,800 – 2,000 |
| Meru | 5.5 – 6.0 | 1,950 – 2,150 |
| Nanyuki | 6.0 – 6.5 | 2,100 – 2,300 |
| Garissa | 6.0 – 6.5 | 2,100 – 2,350 |
| Lodwar | 6.5 – 7.0 | 2,300 – 2,600 |
| Marsabit | 6.0 – 6.5 | 2,100 – 2,350 |
Design tip: Size off-grid systems for the worst month (often March–April or July–August) to avoid shortages during cloudy periods.