Solar
Solar vs Generator: Which Is Cheaper to Run in Kenya?
Short answer
Solar costs more to buy but very little to run, while a generator costs less to buy but burns fuel for every unit. As an illustration, a diesel generator using about 0.3 litres per kWh at KES 200 per litre costs about KES 60 per kWh in fuel alone, before servicing. Many sites combine solar for daily use and a generator for long outages.
The running-cost arithmetic
Fuel cost per kWh ≈ litres per kWh × fuel price. A mid-size diesel generator often uses roughly 0.25 to 0.4 litres per kWh depending on load. At an assumed KES 200 per litre (check current pump prices) and 0.3 L/kWh, fuel costs about KES 60 per kWh. Oil, filters and servicing add more. Grid power at an illustrative KES 25 per kWh is cheaper than that, and solar energy has no fuel cost once installed.
Side by side
| Solar (with batteries) | Diesel generator | |
|---|---|---|
| Upfront cost | Higher | Lower |
| Cost per unit of energy | Very low after installation | High (fuel and servicing) |
| Noise and fumes | None | Yes |
| Maintenance | Low | Regular servicing |
| Runs for days without sun | Limited by battery | Yes, with fuel |
| Best use | Daily power and short outages | Long outages and heavy loads |
When a generator still makes sense
- Heavy loads that would need a very large solar and battery system.
- Very long outages or sites needing guaranteed backup.
- Short-term needs such as construction sites.
The combined approach
A hybrid system uses solar and batteries for everyday needs and starts a generator only when batteries run low. This cuts fuel use and generator wear. See generator installation and solar energy.
Common questions
Is solar cheaper than a generator?
Over time, usually yes for regular use, because there is no fuel cost. A generator is cheaper to buy but expensive to run.
Can solar replace a generator completely?
For many homes and shops, yes. For heavy loads or long outages, a generator may remain as backup.
How much diesel does a generator use?
It varies with size and load. Check the maker datasheet fuel consumption at 50% and 75% load.