PV power diverter

[SteamyTea]

Read on here about a few failures, trouble setting them up and problems when the inverter and consumer unit are a fair distance apart.

 

So how about this for a barmy idea.

Rather than sense current flow though the physical wires, just monitor the sun with a cheap sensor set at the same angles as the PV array.

Then basic logic circuit to turn on and off devices depending on the numbers.

Would take a bit of calibrating, but that could be built into the software.

 

Thoughts anyone?

[ProDave]

I once thought that wouldn't it be good if every device could be controlled from one central point.   So for example:

 

When the sun is shining and not otherwise being used, turn the freezer to a lower temperature, and then overnight when no sun turn it back to a less cold (but still freezing) temperature

 

Make some devices that are not time critical "pause" when something more important is using the power, like the heating element on a washing machine, if there is not enough power immediately, it will just take a bit longer to do the wash as it waits for something else to stop.

 

All this of course would be great in a boffins house, but imagine the complexity trying to market some kind of consumer product oriented communication system and build that into appliances.  It would be so complicated and unreliable.

 

Battery storage should largely solve all this, if working properly it charges to soak up any PV generation not being used, and discharges as much as it can to feed loads when not enough generation.  That really really needs to be widely available with a reliable wireless connected current probe with a decent range.  I don't know if that is the case?

 

As regards reliability.  I have repaired a couple, and was generally disappointed with the build quality and lack of basic understanding.  The things that stood out were PCB tracks burning out because they could not handle the current.  Jump leads to power devices doing the same.  And power devices failing due to over heating either by not having a decent heat sink or even worse just no heat sink compound used.  Some shockingly bad and so simple to avoid design mistakes.

[JohnMo]

Home assistant will track sun angles if you want, it also has integration with solar forecasting such as Solcast.

 

So you get all this sort of information 

So you don't need to know really what is actually going down the wires, with CT clamps etc.

 

Mine is currently putting 5kW into the floor and 3kW into DHW, that stops at predetermine battery SoC or 2.5 hrs before sun set which ever comes first. All software driven via home assistant. The big solid state relay does what home assistant says for the immersion, while a small Shelly relay sets the heat pump at a higher flow temp, so it will run on demand.