EV Charging with Solar and Energy monitoring

[Darinf]

We recently bought our first EV (23 Ioniq 5 Limited). We have had a solar panel system for many years.
We also recently had an Emporia level 2 charger installed.

I noticed that Emporia offers integration with their EVSE and their home energy monitoring products where they say you can set it up so that your EV only charges when there is excess solar being generated. It seems like they market that feature as kind of charging your EV directly from your solar panels.

Here in San Diego we are on a grandfathered NEM 2.0 plan that trues up once a year. But one nice thing about the NEM and TOU plan is that any excess power we generate is credited to our account at the full rate in effect when the power is being generated. So most of our excess power is generated during off-peak or peak TOU times. In the summer, our peak rate (4pm to 9pm) is $0.65158/kWh and off-peak (6am to 4pm) is $0.39308/kWh and super off-peak (12am to 6am) is $0.31333.

Finally, my question is, doesn’t it make more sense for me to still charge during super off-peak times rather than charge when the solar is generating excess power? So using the Emporia “feature” would be worse than charging during super off-peak times?

If our solar generates an extra 1kWh at 4pm, we would get a credit of $0.65158. Then if I charge the car after midnight, I could charge the car over 2kWh using the $0.65158 credit I received earlier in the day.

So in our case, there’s no advantage to us buying an Emporia energy monitoring system since charging our car during excess solar generation isn’t the best time.

[MrWassen]

I agree that you strictly speaking do not need an energy monitor to know when to charge your vehicle in your situation. When on NEM 2 and on a TOU plan, you should consume power as if you don’t have solar, i.e. for most TOU plans that typically means EV charging from midnight to 6 weekdays and midnight til 2 pm. on weekends.

The only exception to this would be if your solar array is significantly oversized, in which case it becomes less important as the NEM 2 true up pays you a pittance for net excess kWh’s come true up time.

That being said, I find the energy monitor to be hugely helpful as it allows you to monitor solar production and all of your high power consumption devices such as el dryer, heat pump, AC, water heater etc, etc. If you are close to being in balance on a yearly true up basis, it will help you to know what to focus on in terms of other appliances etc. to ensure that you end minimizing/eliminating any true up payment.

The only issue I have is that the utility rates are outdated. The app allows you to select your TOU plan (in our case SDGE EV-TOU-2) but in looking at the consumption stats it seems to apply rates that are 1+ year old.

EMPORIA: PLEASE FIX THIS!!

[Author]

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