Solar
Is Solar Worth It in Kenya? A Step-by-Step Payback Calculation
Short answer
Solar is usually worth it in Kenya when you use a lot of electricity during the day and pay a high per-unit price. In our worked example, a 3 kWp system that offsets about 70% of its output pays back in roughly four years. Your result depends on your tariff, how much solar power you use directly and the installed cost.
Step 1: Find what you really pay per unit
Divide your total electricity bill by the units (kWh) you used. This includes fuel charges, levies and taxes, so it is higher than the base tariff. In the example below we assume KES 25 per kWh. Replace this with your own figure.
Step 2: Estimate how much a system produces
In Nairobi, a conservative planning figure is about 4 kWh per kWp per day after losses. A 3 kWp system therefore produces about 12 kWh per day.
Step 3: Work out how much you use directly
Without approved export to the grid, only the solar power you use at the time counts. Homes that are empty in the day use less of their own output. Offices and shops use more.
Worked example: 3 kWp grid-tied system
Assumptions: KES 25 per kWh, 12 kWh produced per day, installed cost KES 300,000 (illustrative, not a quote).
| Share of solar used on site | Savings per year (KES) | Simple payback |
|---|---|---|
| 50% (6 kWh/day) | 54,750 | about 5.5 years |
| 70% (8.4 kWh/day) | 76,650 | about 3.9 years |
| 90% (10.8 kWh/day) | 98,550 | about 3.0 years |
Savings = kWh used per day × KES 25 × 365. Payback = cost ÷ yearly savings. This ignores tariff changes, panel ageing and financing.
What changes the answer
- Batteries. A hybrid system costs more, so payback is longer. You are also buying outage protection, which has value beyond bill savings.
- Tariff changes. Higher tariffs shorten payback; lower ones lengthen it.
- Replacement costs. Panels last 20 years or more, but inverters and batteries may need replacing within that time.
- Shading and roof direction. Poor sun exposure reduces output.
When solar may not be a good fit
- Most of your electricity use is at night and you do not want batteries.
- Your roof is heavily shaded or too small.
- You are planning to move within a few years.
- Your monthly bill is already very low.
Common questions
How long do solar panels last?
Panels typically carry long performance warranties and keep producing for 20 years or more, with a small output loss each year. Inverters and batteries have shorter lives.
Does solar increase property value?
It can make a property more attractive by cutting running costs, but the effect varies by market and buyer.
Should I choose hybrid or grid-tied for the best payback?
Grid-tied has the shortest payback on bill savings. Hybrid adds backup power, which matters if outages cost you money or inconvenience.