EV charger synced with solar production

[brian.medema]

I’m excited about the new EV charger. I have both solar panels and an EV, and I would be interested in a setting that turned on the Emporia EV charger when my Vue2 sees my solar panels are sending electricity to the grid, so the excess electricity would instead charge my car, and also turned off my EV charger when my solar panels are not over-producing AND it’s during my utility’s peak rate hours.

[Germerican]

This might be a nice feature that I hope the emporia team will be looking into. As of now, you can schedule charging based on sun rise and sunset, there is a setting that allows to adjust for +/-1h, so you could tell the charger to start charging 1h after sun rise and stop 1h before sun set. But that of course does not factor in your actual PV energy production (e.g. like on cloudy or rainy days).

Should not be to hard to integrate that, however, most EV’s negotiate the charging rate at the beginning of the session, not sure how they would deal with an variable amp/kw input as it would be with your thought excess production.

[djwakelee]

Once plugged into a vehicle, the EVSE (charger) sends the pilot signal per the J1772 standard.  This PWM signal is present for all connected states – charging or idle.  So the EVSE can adjust this anytime during charging, and the vehicle will adapt to the new rate.  Dynamic adjustment during charging is no problem – the EVs must support it per the standard.

Adjustment of this signal is common, such as in commercial settings where many vehicle chargers share the same power source.  For example, if two vehicles are charging at a shared dual station – the advertised maximum rate will be less, but then will go up when one stops – and the remaining vehicle can consume more power at that time.

[brian.medema]

I just got a marketing email, and apparently this is now a supported feature! Woohoo!

“Pair with your Emporia Vue and your 2.4 GHz Wifi to set the Charger to charge your car when your system is producing excess solar energy. Also automate charging based on Peak Demand and Time-of-Use plans.”

[daklein]

The integration with the Vue monitor and the excess solar EVSE control is why I purchased the EVSE & Vue bundle.  (plus a rebate from my utility)    Does the excess solar feature start & stop the EVSE as well as vary the charging current?

[brian.medema]

Hi Daklein!

I haven’t put it through extensive testing, but it seems to work pretty well for me! The excess solar feature only kicks in if you have another rule that would normally turn off or restrict the EVSE, such as peak demand or time-of-use, is in force. In those cases, if you have excess solar energy, the evse will turn on and modulate the charging rate to obey the other rules.

For example, I have my evse scheduled not to charge from 4pm to 8pm, when my utility has a higher rate. However, if the house is exporting power during those hours, the EVSE will turn on at level that keeps the grid useage right around 0 kw. It’s not prefectly respnosive, but I think it responds within about a minute, and since my utility measures based on a 30 minute window, it’s been pretty awesome!

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