Electric cars, boda bodas and delivery vans are arriving fast in Kenya, and charging them from solar is an obvious idea in a country with strong sun all year. The sizing is simpler than it sounds: work out the energy each vehicle uses per day, then divide by what a kilowatt of panels produces.
Step 1: daily charging energy
Energy per day is distance multiplied by consumption, plus about 10% lost in the charger and battery.
| Vehicle | Typical use | Consumption | Charging energy per day |
|---|---|---|---|
| Electric car | 50 km a day | 16 kWh per 100 km | 8.9 kWh |
| Electric boda boda | 120 km a day | 4 kWh per 100 km | 5.3 kWh |
| Electric delivery van | 100 km a day | 22 kWh per 100 km | 24.4 kWh |
Real consumption depends on the model, load, speed and terrain, so use your vehicle's figure if you have it.
Step 2: what a kilowatt of solar produces
Kenya receives about 4.9 peak sun hours a day on average. After losses from heat, dust, wiring and the inverter (a performance ratio of about 78%), each kilowatt of panels produces roughly 3.8 kWh a day.
Step 3: divide
| Vehicle | Solar needed | Panels (620 W) | Grid cost avoided per month |
|---|---|---|---|
| Electric car | 2.3 kW | 4 panels | about KES 7,500 at the DC2 rate |
| Electric boda boda | 1.4 kW | 3 panels | about KES 4,500 at the DC2 rate |
| Electric delivery van | 6.4 kW | 11 panels | about KES 18,500 at the e-mobility day rate |
The monthly figures assume 30 days of charging at the all-in rate of KES 28.30 per kWh for a domestic DC2 connection, or KES 25.19 for the KPLC e-mobility daytime rate. Our breakdown of what a KPLC unit really costs shows where those rates come from.
The catch: the sun has to be up when the vehicle is plugged in
Solar charging works best when vehicles charge during the day: at a depot between shifts, at the workplace, or at a boda stage or swap station. A car that only charges overnight at home cannot use solar directly. It needs a battery to store the daytime energy, which adds cost and losses.
For overnight charging, compare that battery with the grid's night rate. On the KPLC e-mobility tariff, night energy costs about KES 15.51 per kWh all-in, which is often cheaper than storing solar in a battery. Daytime solar replacing the KES 25.19 to 28.30 daytime rate is where the savings are largest.
Plan for the cloudy months
Output drops in the long rains and the overcast June to August period. In July, Kenya's weakest month on average, the four-panel car system above produces about 6.7 kWh a day, short of the 8.9 kWh needed. Either add a panel or two, or accept some grid charging in those months.
Check your own numbers
- The free solar calculator adds EV charging to your household or business load, for cars, boda bodas, vans and buses, and shows the panel count and savings.
- Solar by county gives the monthly sun hours for your area, which can be noticeably higher in the north and east than the national average.
- For fleets and depots, see EV charging infrastructure for charger types, scheduling and the e-mobility tariff.