By size
30kVA Generators
A commercial and light-industrial size where capacity is comparatively cheap, because the expensive threshold was crossed at 20kVA rather than here.
Suits
- Larger apartment developments
- Light industry and workshops
- Schools, churches and institutions
- Cold storage and food processing
Where capacity gets cheap
The step from 12 kVA to 20 kVA roughly quadruples the price, because it crosses from imported sets into industrial plant. The step from 20 kVA to 30 kVA costs around 8 percent: approximately KES 970,000 to KES 1,050,000 for 50 percent more output, and a 50 kVA Cummins at around KES 1,660,000 continues the pattern.
Once you are buying real plant, the engine and alternator are the bulk of the cost and the incremental capacity is comparatively inexpensive. This is the only part of the Kenyan range where “buy some headroom” is straightforwardly good advice.
But not unlimited headroom
A generator running permanently at a very low fraction of its rating develops its own problems. Diesel engines lightly loaded for long periods wet-stack, glaze their bores and carbon up their exhausts, and the fix is a load-bank exercise or an engine overhaul.
So: one genuine size of headroom above your assessed load is prudent, particularly if the business expects to add plant. Three sizes is a machine that will deteriorate from under-use while you pay to service it.
Fuel becomes a project
At 30 kVA and above, fuel stops being a jerrycan question. A set running for extended periods needs bulk storage, and bulk storage brings tank specification, bunding against spillage, and EPRA storage requirements into the project. Underground storage attracts additional permits and inspection. We raise this at quotation, because discovering it at commissioning stops a job.
FAQ
▸How much more is a 30kVA than a 20kVA?
Much less than you would expect. A 20kVA Cummins lists around KES 970,000 and a 30kVA around KES 1,050,000, roughly 8 percent more for 50 percent more output. The expensive step was entering industrial plant at 20kVA; capacity above that is comparatively cheap.
▸Should I buy headroom while it is cheap?
Within reason, yes, and this is the one place in the Kenyan range where that advice holds. But a heavily oversized set running at a small fraction of its rating regulates poorly, wet-stacks and carbons up. Buying one size of genuine headroom is sensible; buying three is not.