Going to Washington: a batch of permanent magnet motors, ordered from Olympia. They were bought as components rather than as a finished machine, which is the more interesting kind of order — somebody in Thurston County has a design of their own and needed a generator good enough to build around. So this is not a page about a wind turbine. It is about what is actually inside the part, what its rating does and does not promise, and what it costs. The most useful section may be the one explaining why the headline number is probably not the number you will get.
Wound stators in their housings, before assembly. Copper, laminated steel, three phases.
What “15 kW continuous, 22 kW peak” actually means
Two ratings, two entirely different limits. The 15 kW continuous figure is what the machine will sustain indefinitely without cooking itself, and it is set by heat: Class 200 °C enamelled wire to IEC 60317-13 GR 2, four kilograms of copper acting as a thermal reservoir, parallel-strand bundling that doubles current capacity and spreads the heat across thin conductors, and a housing that cools passively. The 22 kW peak is short-term overload for transients, and it is bounded by physics of a different sort — the demagnetisation threshold of the N42 magnets and saturation of the stator iron.
Here is the part that matters more than either number. A generator rating describes what the machine can absorb without damage. It says nothing about what it will produce. That depends entirely on what you connect to the shaft. Maximum speed is 2,000 rpm, efficiency is about 95% at rated load, and it runs bidirectionally — but a modest rotor turning slowly will draw a small fraction of 15 kW out of it, and no amount of generator headroom changes that.
A rating is a ceiling, not a promise. What turns the shaft decides the number you actually get.
We would rather say that plainly than sell one to somebody expecting fifteen kilowatts from a small rotor in light air. The headroom is still worth paying for — a generator run permanently at its limit is the most reliable way to kill a machine early, and this one at a typical few kilowatts is loafing — but headroom and output are not the same thing.
What is inside it
A 12-pole stator with 36 slots, three-phase distributed winding in a fractional-slot configuration for minimal cogging and a clean sinusoidal output. Ninety wires per slot — two parallel strands of forty-five turns, 0.70 mm enamelled copper, the insulation grade used in industrial servomotors and EV traction motors. Four kilograms of copper in total.
The rotor carries 24 NdFeB N42 magnets, bread-shaped, 60 × 25 × 5 mm and nickel-coated — 180 cm³ of magnet in total. They are mounted skewed, which cuts cogging torque by around 80%: smoother torque, easier starting, longer bearing life. The core is not a casting but a stack of 240 individual 0.5 mm silicon-steel laminations built up to 12 cm, about 16 cm in outside diameter, which is what keeps eddy-current losses down. Machining is held to ±0.05 mm, and the unit is EMC compliant to EN 61000-6-3. All in, it weighs 20 kg.
None of that photographs well and none of it appears on a box. It is, however, the entire difference between a generator that is still turning in ten years and one that is not.
Olympia — state capital, county seat of Thurston County, at the head of South Puget Sound.
Where they are going
Olympia is the capital of Washington and the county seat of Thurston County, a city of 55,605 people at the 2020 census anchoring the South Puget Sound region, about fifty miles south-west of Seattle. Its downtown is partly built on filled tideland from the dredging that created the deep-water port, and its climate is warm-summer Mediterranean — dry Julys, and the rain arriving between November and January.
We do not know what these motors are for, and we are not going to invent a story about it. This model goes into electric vehicles, industrial machinery, marine installations, robotics and off-grid power systems, and a port city is a plausible home for most of those. One thing is worth saying regardless: if the intended use is wind, the head of Puget Sound is a sheltered inland waterway, and it is a considerably weaker wind resource than the Washington coast or the Columbia Gorge. That is not a reason against the motor. It is a reason to measure before sizing anything around it.
What it costs, and what it does not include
The motor is ZAR 9,900 on this store as this is published, on the product page, itemised, with nothing held back for the checkout. That buys the machine on its own: generator, housing, shaft. It does not buy a rotor or blades, a mount or a tower, a rectifier, charge controller, inverter or batteries, the wiring between any of them, or the electrical work and permissions that apply where you are. A component sale is honest about being a component.
If you are building something wind-driven around it, one more purchase comes first: an anemometer at ZAR 5,900. Power in the wind goes with the cube of speed, so a site that is 20% slower than you assumed gives roughly half the energy. A season of real measurements at your own address is worth more than any figure we could publish about ours.
Our thanks to the customer in Olympia for the order. Every specification above comes from our own published data for this model and is checkable on the product page; the price is the one on this store on the day of publication. If you are designing around a generator, hold us to all of it.