Change the order of how PV generated Elec is used

irewestlad · 19-03-2022 10:12pm #1

Hey all

I have a 22 panel system now producing some nice figures since coming into March with the better weather. The system includes an Eddi and a 5kWh Solis battery.

On good days, I’m exporting to the grid but because of orientation of house, I produce the majority of electricity before 2pm.

I’ll be getting an EV car later this year, and would like to allow some of that excess to go to the car. But due to the specs of the plug used for elec cars, it won’t charge with less than 1.4kw coming from panels. (Meaning I would need to supplement the PV production if excess falls below 1.4 with grid supply…open to correction on this, but seems to be what I’ve read)

So… what I’d like to do is

— if production is high, and car is plugged in, charge the car for X hours.

— after X hours, charge the house battery

— after house battery is charged, let the Eddi kick in.

Any suggestions how I might set this rule up so that it is an automated process?

Thanks

the_amazing_raisin · 19-03-2022 10:21pm

Use a Zappi, they're from the same company that make the Eddi and the two can communicate. You can set the priority of which will switch on first

https://myenergi.com/wiki/zappi-v2/13650-2/

The Zappi has a setting that will allow to set a minimum amount of power coming from PV when it's diverting. So if you set it to 50% and you're producing 1kW from PV, then you'll take 400W from grid. If you set it to 100% then it'll only divert to the EV of there's a minimum of 1.4kW from PV. You can also program an overnight boost to ensure you have enough charge in the EV no matter what

https://myenergi.com/wiki/zappi-v1/zappi-charge-modes-and-boosts/

the_amazing_raisin · 19-03-2022 10:24pm

Just noticed you want the EV to charge before the house battery. Not sure how you'd accomplish this and tbh I'd recommend swapping them around

The PV is there to serve the house first, then diverters, then the grid. Charging the EV from solar is best done opportunistically and the focus should be on charging the house battery to meet demands on the evening

Don't worry, charging an EV at night rates is still vastly cheaper than petrol (especially at today's prices)

graememk · 19-03-2022 11:42pm

My energi cant see the status of the batteries, only the power coming from the inverter.

so without any external "meddling" battery is charged first, and then the eddi kicks in, and once the excess is greater than 1.4kw, the zappi can start.

If you want to go down the rabbit hole of automation, im sure it would be possible. Using a combination of talking to the inverter to get the status of the battery, some poking with the myenergie api but nothing turnkey.

irewestlad · 19-03-2022 11:56pm

Super @the_amazing_raisin and @graememk, this has given me great direction. I was aware of the Zappi so it’s the obvious choice for me, thanks for the direction

Change the order of how PV generated Elec is used

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