5.8 peak sun hours a day
Nairobi receives 5.8 kWh/m² of solar energy a day, so each kilowatt of panels produces roughly 1,658 kWh a year. June is the weakest month; size essential loads to still work then.
Nairobi County
Solar power in Nairobi County.
What solar, battery backup and EV charging look like in Nairobi: the county's solar resource month by month, what a typical system produces, local design points for a highland climate, and a calculator using your KPLC bill.
Plan for the cloudy months
Highland output dips during the long rains and the cool, overcast June to August period. Size the system on the yearly total and check that the low months still cover essential loads.
Cool temperatures help panels
Panels lose efficiency as they heat up, so cooler highland air partly offsets the cloudier months.
Savings at KPLC rates
Most sites are on the grid, so savings come from replacing energy you would otherwise buy at your all-in KPLC rate, plus backup during outages.
Kenya electricity tariffsMonthly solar resource in Nairobi
Long-term average daily solar energy on a horizontal surface and air temperature from NASA POWER, with the output of an example 5 kW system. Near the equator a low-tilt array receives close to the horizontal value.
| Month | Solar energy (kWh/m²/day) | Air temperature (°C) | 5 kW system output (kWh) |
|---|---|---|---|
| January | 6.54 | 20.5 | 790 |
| February | 6.86 | 21.4 | 749 |
| March | 6.66 | 21.6 | 805 |
| April | 5.81 | 20.5 | 679 |
| May | 5.26 | 19.3 | 636 |
| June | 4.74 | 18.7 | 554 |
| July | 4.85 | 18.7 | 586 |
| August | 5.17 | 19.2 | 625 |
| September | 6.06 | 20.3 | 709 |
| October | 6.10 | 20.8 | 738 |
| November | 5.75 | 20.2 | 673 |
| December | 6.10 | 20.0 | 737 |
| Year | 5.82 average | 20.1 average | 8,283 |
Estimate a system in Nairobi
- Solar array
- 3.72 kWp 6 × 620 W panels, about 17 m² of roof
- Inverter
- 3 kW Hybrid, with battery
- Battery
- 6.0 kWh usable About 6.7 kWh nominal lithium (LiFePO₄)
- Estimated savings
- KES 12,474/month 83% of energy charges, KES 149,687 a year
- Solar generation
- 6,163 kWh/year 5,289 kWh used on site
- Simple payback
- Add a quote Before financing and maintenance
Show monthly table
| Month | Generated (kWh) | Used on site (kWh) | Savings |
|---|---|---|---|
| Jan | 588 | 456 | KES 12,908 |
| Feb | 557 | 412 | KES 11,659 |
| Mar | 599 | 456 | KES 12,908 |
| Apr | 505 | 441 | KES 12,491 |
| May | 474 | 456 | KES 12,908 |
| Jun | 412 | 400 | KES 11,329 |
| Jul | 436 | 423 | KES 11,972 |
| Aug | 465 | 449 | KES 12,714 |
| Sep | 528 | 441 | KES 12,491 |
| Oct | 549 | 456 | KES 12,908 |
| Nov | 501 | 441 | KES 12,491 |
| Dec | 549 | 456 | KES 12,908 |
Want this sized with real equipment, cable runs and supplier prices?
Get a detailed planEstimate only. It uses NASA POWER long-term modelled data for Nairobi, a 78% performance ratio and reviewed KPLC all-in energy rates. Fixed and demand charges, shading, export credit and tariff changes are not included.
Frequently asked questions
How much sun does Nairobi get for solar?
Nairobi receives about 5.8 kWh of solar energy per square metre per day on average (5.8 peak sun hours). February is the strongest month at 6.9 and June the weakest at 4.7. Source: NASA POWER long-term modelled data for Nairobi.
How much does a 5 kW solar system produce in Nairobi?
About 8,283 kWh a year, or 22.7 kWh a day on average, assuming a 78% performance ratio for heat, dust, wiring and inverter losses. Output ranges from about 554 kWh in June to 749 kWh in February.
How many solar panels does a home in Nairobi need?
A home using 300 kWh a month with half of it in daylight needs about 1.1 kW of solar for its daytime use, which is 2 panels of 620 W. Covering evening use as well needs a battery and a larger array. Use the calculator on this page with your own bill.
Can StimaPulse plan a solar, battery or EV charging project in Nairobi?
Yes. StimaPulse sizes solar, storage and EV charging for homes, schools, businesses and fleets anywhere in Nairobi County, using your bills or meter data, the site's own solar resource, real equipment and supplier quotes. A licensed engineer must verify the final design before installation.
Get a plan for your site.
Bring a utility bill, load list, fleet schedule or supplier quote. We will turn it into a sized, costed and comparable plan.