Direct Current PV heating

[Radian]

Continuing this topic in its own thread, my reply to  @SteamyTea is that yes, this sounds like it could have mileage.

However, DC breaking is, as you are aware, more onerous than for AC...

 

 

[SteamyTea]

Would it just be easier to make up an electronic breaker?

Though there is beauty in the simplicity of a bimetallic strip.

 

Or the cheap inverter idea.

https://www.ebay.co.uk/itm/384595771597

Edited February 17, 2022 by SteamyTea

[Radian]

As you know, there's no mechanical Arc Suppression in the bimetallic thermostats designed for AC so they would have to be bypassed or set to maximum (and not relied upon) and replaced with a DC contactor controlled by an additional thermostat. I would have expected this to still come in under the cost of an inverter as well as delivering greater efficiency.

 

12V invertors are a total joke. 100 Amps or more to get anywhere close to a kilowatt is madness! If you found a 48V off-grid invertor, that might make sense.

Edited February 17, 2022 by Radian

[SteamyTea]

6 minutes ago, Radian said:

12V invertors are a total joke. 100 Amps or more to get anywhere close to a kilowatt is madness! If you found a 48V off-grid invertor, that might make sense

Yes, never thought of that.

See what I can find in the 48V range.

[JohnMo]

You could use a MyPV, immersion.  Designed for DC, and direct connection to a 2kW array. No switching issues.

[SteamyTea]

52 minutes ago, JohnMo said:

MyPV, immersion

Seems they need more than just the element/thermostat combo.

https://www.estg.eu/en-gb/mypv-immersion-heater-3kw/

[JohnMo]

7 minutes ago, SteamyTea said:

Seems they need more than just the element/thermostat combo.

https://www.estg.eu/en-gb/mypv-immersion-heater-3kw/

That's the wrong immersion.

 

This is the correct one, come with it own MPPT.

https://www.my-pv.com/en/products/elwa

[SteamyTea]

1 minute ago, JohnMo said:

https://www.my-pv.com/en/products/elwa

Can't get past the cookie and invite screen, so won't be seeing what it is about.

I wish websites would stop offering a choice, when there is no choice.

[JohnMo]

Try this.

https://www.zerohomebills.com/product/mypv-dc-elwa-solar-pv-water-heater/

 

[SteamyTea]

1 minute ago, JohnMo said:

Try this.

https://www.zerohomebills.com/product/mypv-dc-elwa-solar-pv-water-heater/

 

Thanks

 

£577.  Get a generator and a few gallons of gasoline for that.

[Radian]

You could use a 3-pole contactor like this (rated for up to 220VDC) and series-parallel up a bunch of modules to suit.