A consignment of TESUP electric motors has gone to Kempton Park, in Gauteng. The customer is Africa Truck Stop, which runs roadside facilities for the people who move South Africa's freight. We are pleased about it, and rather than write the usual paragraph about being pleased, we thought we would tell you what actually went in the crate and what the same equipment costs.
Where this is, for anyone picturing it wrong
Kempton Park sits on the Highveld at around 1,600 metres, beside OR Tambo International, on the road network that carries traffic between Johannesburg and Pretoria. It is about 500 km from the sea. If you had a beach in mind, that is the wrong picture — this is high, dry, open country, and it is windy in the way that open country at altitude usually is.
Sandton, Johannesburg — the same province, about twenty kilometres from Kempton Park.
Altitude matters to a turbine, and not in your favour. Air at 1,600 m is roughly 15% less dense than at sea level, and the power in the wind is directly proportional to air density. The same wind speed on the Highveld therefore carries about 15% less energy than it would on the coast. Any output figure you read anywhere — ours included — is quoted at sea-level density unless it says otherwise. It is a small correction, but it is the sort of thing you would rather hear from us now than work out for yourself later.
Thin air costs you about 15% of the energy in the same wind. Nobody puts that on a spec sheet.
What is actually in a TESUP motor
The generator is the part that decides whether a small turbine lasts. Ours is rated 15 kW continuous — considerably more capacity than the machine is ever asked to deliver, which is deliberate, because headroom is what stops a generator cooking itself on the gusts. Inside it: a 24-magnet rotor running NdFeB N42 magnets, four kilograms of pure copper winding, and a silicon-steel laminated stator core rather than a cheap casting that overheats.
The details that photograph badly are the ones that matter. Skewed magnet mounting cuts cogging torque by around 80%, which is what lets a rotor start in light air instead of standing still. The winding uses Class 200 °C enamelled wire to IEC 60317-13 — the insulation grade used in industrial servomotors and EV drivetrains. Machining is held to ±0.05 mm. All of it comes out of our own European factories, where we make over 270 components in house.
The N1 — the road that carries most of what South Africa moves.
What a complete machine costs here
A generator on its own is not a wind turbine. Here is every line of a working one, at the prices on this store as this is published.
| Magnum generator — 15 kW motor, 12 kW peak | $399 $1,299 |
| Blade set — carbon fibre composite, swappable | $349 |
| Charge controller — sets the voltage limit, brakes the rotor in a storm | $199 |
| A complete, working machine | $947 |
That is roughly $79 for each kilowatt of peak output, or about $249 per kilowatt of the rated figure. What it does not buy is a mast, a foundation, cabling, batteries, an inverter, or the electrical work and permissions that apply where you are. None of that is hidden — it is simply site-specific, and anyone quoting you one all-in number has not seen your site.
Before you buy anything: measure your wind
Sunrise over open country. Two sites a street apart can differ by a factor of two.
Every number above is worthless without one we cannot supply: the wind at your address. Power goes with the cube of wind speed, so a modest difference in site is an enormous difference in output — and on the Highveld you have that 15% density correction sitting on top. An anemometer costs a fraction of a turbine and settles the question inside a season.
Then put your own measurements into the calculator on the Magnum page — your wind, your tariff, your roof or your yard. For some of you it will say the numbers work comfortably. For others it will say a turbine is the wrong purchase at your address, and we would far rather it told you that before you bought one than after.
Our thanks to Africa Truck Stop for the order. Prices are those on this store on the day of publication and are checkable on the product page at any time. If you are weighing this up wherever you are, measure first — and then hold us to every figure above.