Anyone else using old washing machine motors for a DIY wind turbine?

Spent a fair bit of time down this rabbit hole last winter. The permanent magnet motors from older front-loaders are genuinely decent candidates — they're robust, already weatherproofed to a reasonable degree, and you can often pick them up from Freecycle or Facebook Marketplace for next to nothing.

The main gotcha is that most washing machine motors are induction motors, not permanent magnet, which means they're essentially useless for wind generation without serious modification. You want to be hunting specifically for the older brushed DC types or, better yet, the BLDC motors from more recent inverter-driven machines (Bosch and Miele seem to crop up most often with usable ones).

Rectification is the other thing people underestimate. Even with a decent motor, you'll be producing wildly variable AC that needs sorting before it touches your battery bank. I'm running a Victron SmartSolar on my van setup and there's absolutely no way I'd connect something this unruly without a proper bridge rectifier and dump load arrangement upstream.

A few things worth thinking through:

• Cut-in speed vs your local average wind speed (the UK is windy, but not that windy unless you're coastal or elevated)
• Blade design matters enormously — a poor blade set will kill your output regardless of motor quality
• Mechanical vibration and fatigue over time on a DIY mount

Has anyone here actually got measurable kWh figures from a washing machine motor build? I've seen a lot of "it spins and charges a bit" posts but not much in the way of proper data logging. Would love to see some actual numbers before committing more time to it.

SilverCaptain | Posts: 847

@BrambleElla great shout on the front-loaders specifically — the drum motors from older Bosch and Miele machines are particularly worth hunting out. One thing I'd add that often gets overlooked: test the cogging torque before you commit to building a full rotor around it. Some of these motors need a decent wind speed before they'll overcome the magnetic resistance and start generating properly, which can be frustrating in the typical light coastal or valley breezes a lot of us are dealing with.

Freecycle and local Facebook Marketplace have been my hunting grounds — washing machine repairs often mean the motor itself is perfectly sound but nobody wants the whole unit.

What blade configuration are you running? I've had better low-wind performance going to three longer blades rather than six shorter ones.

BatteryPaula | Posts: 1,203

@BrambleElla spent a weekend rewiring one of these into a low-wind turbine for the shepherd's hut and honestly the biggest challenge wasn't the motor — it was convincing my Victron MPPT that "yes, this chaotic spinning thing is a legitimate power source, please calm down."

MrBodge | Posts: 2,341

Worth noting that the three-phase AC output from these motors needs proper rectification before you see anything useful on the DC bus. A decent 3-phase bridge rectifier (Schottky diodes, not the cheap silicon ones) makes a noticeable difference to efficiency at low RPM — exactly where narrowboat and van setups spend most of their time.

The bigger headache I found is cut-in speed. Most washing machine motors need a surprisingly brisk wind before they overcome internal resistance and actually start charging. @BatteryPaula did you address that on yours? On my boat I ended up rewinding alternate poles with heavier gauge wire to drop the cut-in threshold, though it's fiddly work.

Also worth having a proper dump load controller — a Victron BMV or similar to monitor, and a resistive dump load. Runaway voltage with no battery load connected will kill your rectifier quickly.

QuietTrekker | Posts: 412

@MrBodge good point on rectification — worth adding that the output voltage varies wildly with RPM on these, so a standard bridge rectifier alone isn't enough. You really want a proper MPPT controller that can handle variable low-voltage input, or you'll dump most of your potential generation.

Been down this exact rabbit hole for my garden office setup. Ended up deciding the faff wasn't worth it vs just adding another solar panel, but the experiments were fun.

One thing nobody's mentioned — cogging torque is a real issue with these motors. Kills performance in low winds. Some people mill slots into the stator laminations to reduce it but that's getting into serious DIY territory.

If you're serious about making it work reliably, Victron's BMV monitoring helps you actually see whether you're generating anything useful vs just convincing yourself it's working 😅