Choosing the right solar panel size is the single most important decision in any home solar project. Get it wrong in either direction — too small and your system underperforms; too large and you've spent money you didn't need to. This guide walks you through the exact process we use when sizing systems for Kenyan homes.
Step 1 — Calculate your daily energy consumption
Start with your KPLC bill. Look at the monthly units (kWh) consumed and divide by 30 to get your daily average. For most Kenyan households, this ranges from 4 kWh/day (modest home with lights and phone charging) to 25 kWh/day (larger home with AC, water pump, and kitchen appliances).
- Monthly units ÷ 30 = daily kWh consumption
- Add 20% buffer for system losses (inverter efficiency, wiring, temperature)
- That figure is your daily solar generation target
Step 2 — Account for Kenya's peak sun hours
Kenya sits close to the equator, which means we enjoy 5–6 peak sun hours per day in most regions — one of the best solar resources on the continent. Nairobi averages 5.5 hours, the Coast region 6.0 hours, and even the highlands average above 5 hours.
Formula: System size (kWp) = Daily kWh target ÷ Peak sun hours. Example: 10 kWh/day ÷ 5.5 hours = 1.82 kWp — round up to a 2 kWp system.
Step 3 — Match panel count to your roof space
A standard 400W monocrystalline panel measures roughly 2m × 1m. A 2 kWp system needs 5 × 400W panels, requiring about 10m² of usable roof. Factor in shading from water tanks, chimneys, and neighbouring buildings — partial shading can drop output by 20–40% if not managed correctly.
Common system sizes for Kenyan homes
- 1–2 kWp: Lights, fans, phone/laptop charging, small TV
- 3–5 kWp: Above + refrigerator, microwave, washing machine
- 6–10 kWp: Full home including water pump and air conditioning
- 10 kWp+: Large homes or those with significant business loads
Step 4 — Don't forget battery storage
Panel size and battery capacity are separate decisions. Your panels generate power during the day; batteries store it for the evening and night. For most Kenyan homes, a battery bank sized for 6–8 hours of average load is the sweet spot between cost and comfort.
At Solarlux Kenya, every system design starts with a full energy audit. We visit your site, measure your loads, and produce a bill-of-materials with transparent pricing. Get in touch for a free consultation.
