A project crying out to be done!

[AE-NMidlands]

didn't our (silent) member and prolific contributor to the old place have really big air-cooled dump resistors for mopping up WT surplus when everything else was full?
I have memories of tubular wire-wound resistors about the size of a 2-litre bottle...

[MikeNovack]

Please note what I was saying (and not saying). I was NOT saying that within some "normal" range of wind speeds a varying load could not be used to control turbine speed. I was saying that could not be the ultimate control because the necessary size of the power load is increasing exponentially, and the third power at that.

In other words, if a "dummy load" of 120 KW was enough to control the wind turbine up to wind speeds of 40 mph then it would require almost a MW if the wind speed went up to 80 mph (weak hurricane). In other words, a control method that works until it fails catastrophically.

HOWEVER -- one important thing to note is "scale factor". We are mainly discussing KW size devices for ourselves, not MW size devices. When you scale something down in size, it becomes relatively stronger.

[Marcus]

didn't our (silent) member and prolific contributor to the old place have really big air-cooled dump resistors for mopping up WT surplus when everything else was full?
I have memories of tubular wire-wound resistors about the size of a 2-litre bottle...

Yes you can get those, and if you're running a diversion controller off the battery at battery voltage they may be the way to go, but in this case, as the output from the turbine is 240v, a bog standard 230v electrical heater may be the simplest option, possibly controlled by the existing proven control box.

If you end up with a battery, an ev, and permission to export to the grid, then you will hardly ever need the dump load. And if I'm correct in thinking that the proven can withstand running unloaded (?) you could, theoretically, get away without one. But if (for example) the battery is full, the ev not there, and the grid goes down, then one of two things can happen:

Your windyboy gti or a mppt controller disconnects 'cos there's nowhere for the power to go - so you need the dump load to activate to limit the output voltage of the turbine to the <max input voltage of the gti/mppt.

Or:
you activate a dump load before the gti/controller shutdown, based on battery voltage.

Personally I would prefer the 1st option, as the gti/controller might shut down anyway, albeit briefly, due to a voltage glitch or something, and they need to be protected from potential input overvoltage.

Having said all of that, i don't actually know what voltage the proven can get to inloaded: if you can get a definitive maximum unloaded voltage value for the proven, and it's within the max input voltage withstand of the gti/controller then you may get away without the dump load.

[Heroformosa]

Yes Marcus, I ran a bog standard 230v heater as my dump load, triggered by the Proven controller when the heat store was full. (The heat store is long gone, so it won't feature in any new system).
An alternative to the solutions to a grid outage would be to drop the turbine, which I would do with a severe gale forecast.
Yes Ken, a system with PV as well as the WT, and batteries is looking like the way to go.

[Gareth J]

If you grid connect the WT, all this discussion about dump loads moot. The Proven is good for something like 100+mph wind iirc as its blades are sprung to present less area to the wind as wind speed exceeds maximum generation. You should grid connect the turbine in my opinion.

That's a shame regarding the heat store, hopefully there is at least a small heat store the heat pump provides DHW via. It would be beneficial to run the heat pump to provide as low a temperature as possible for the home heating and rely on immersion/s and diverters to top up the DHW temperature. You'll get the maximum efficiency of the HP while retaining gpot DHW temperature.

[AE-NMidlands]

If you grid connect the WT, all this discussion about dump loads moot.

Is that true? I have got the impression that the normal export from my inverter has been wound down a bit from 3.6 kW because of the grid voltage. However that might be because of the house's demand from the inverter which can only output 3.6...

[Gareth J]

If you grid connect the WT, all this discussion about dump loads moot.

Is that true? I have got the impression that the normal export from my inverter has been wound down a bit from 3.6 kW because of the grid voltage. However that might be because of the house's demand from the inverter which can only output 3.6...

Looks like I'm wrong wrt that:
https://www.reuk.co.uk/wordpress/wind/p ... d-turbine/

You are correct, if it's wired for 24 or 48v charging, unless it can be rewired for high voltage output it's limited to battery charging with a dump load.

Apologies for the misdirection.

Edit;
Ah, but I've just realised the OP turbine is wired for higher voltage output so, inverter to grid without batteries and dump load is doable