The 11kV versus 33kV question comes up on nearly every medium voltage project we quote, and it is never purely technical. It is a cost question, a geography question, and — more often than people expect — a question about what the local utility will actually accept.
Here is the honest, no-brochure version of how the decision tends to play out.
The short version
If the power only has to travel 15-20km or less and you are feeding a localized industrial zone or a mid-size factory, 11kV is usually the cheaper path. If you are covering real distance — a 50MW solar farm spread over square kilometers, or a mine far from the nearest substation — 33kV saves you a fortune in cable and in line losses over the life of the project.
What 11kV does well
11kV is the default voltage of medium voltage distribution across huge parts of the Middle East, Southeast Asia, and Africa. The KYN28-12 panels we ship are mostly configured for 11kV or 12kV systems, because that is what the market asks for.
The cost picture is genuinely in its favor:
- Equipment runs 15-25% cheaper than 33kV equivalents. The panels are smaller, the bushings shorter, the terminations simpler.
- Cable is dramatically cheaper. 11kV XLPE costs roughly half of 33kV per meter at the same current rating.
- 11kV/0.4kV transformers are made in staggering volumes across China, India, and the Middle East, so they are cheap and always available.
- Clearances are smaller, which means a smaller substation building.
Where it falls apart is distance. Beyond about 15-20km, voltage drop starts to bite. Every kilometer of 11kV cable drops roughly 0.15-0.2% at full load. And for big loads above 15-20MW, the currents get high enough that the switchgear starts to feel oversized and expensive per megawatt.
What 33kV buys you
33kV exists for the jobs 11kV cannot do. The KYN61-40.5 is one of our best sellers for African and Middle Eastern projects precisely because those projects tend to cover distance.
- You can push power 30-50km without worrying about voltage drop. That matters for mine sites, pipeline pumping stations, and utility-scale solar.
- Line losses (I²R) drop by roughly 90% versus 11kV for the same power, because the current is a third as large.
- A single feeder carries far more. At 1250A, a 33kV circuit moves about 70MW; the same current at 11kV manages only about 23MW.
The catch is cost and skill. A KYN61 panel runs 20-30% above a KYN28 of equivalent rating. The cable is nearly double per meter. And 33kV terminations need properly trained technicians — a badly made joint on a 33kV cable is a failure waiting to happen. The substation also needs more physical room for the larger clearances.
The numbers side by side
| Parameter | 11kV | 33kV |
| Typical switchgear | KYN28-12 | KYN61-40.5 |
| Max power per feeder (630A) | ~12 MW | ~36 MW |
| Max power per feeder (1250A) | ~23 MW | ~70 MW |
| Effective distance | 10-15 km | 30-50 km |
| Switchgear cost index | 1.0 | 1.2 – 1.3 |
| Cable cost index | 1.0 | 1.8 – 2.2 |
| Panel footprint | ~1.2m x 2.5m | ~1.6m x 3.0m |
What we actually recommend, region by region
In practice, the right answer tends to sort itself out by sector:
Industrial plants and factories: 11kV, unless the plant draws more than 15-20MW or the incoming line runs beyond 10km. Most of the factories we supply in Nigeria, Kenya, and Vietnam run happily on 11kV.
Solar and wind: the collector network inside a large plant usually runs at 33kV, then steps up from there to the transmission voltage. That is where the YBW and ZFS substations come in.
Mining: go 33kV from the start. Mines expand, and re-cabling a whole site later is ruinously expensive. Starting at 33kV avoids that.
Utility distribution: follow the existing network. Saudi Arabia and the UAE lean on 13.8kV. South Africa uses 11kV and 22kV. Check the local standard before you order — we always ask.
One thing everyone forgets
Before you commit, check the earthing arrangement. 11kV and 33kV systems are typically resistance-earthed or solidly earthed depending on the utility. That choice drives your protection relay settings and whether you need neutral-earthing equipment. We have watched projects stall because the earthing transformer was ordered late. It is a small item that quietly sits on the critical path.