Pro/Con of backing up two EVSE or not?

[YRide]

The system is designed when on-grid to send PV or powerwall power to offset those loads which are not backed up. I would say it causes issues with the algorithm for there to be large house loads that are NOT monitored.

Is that not ideal in my case per the comments (below quote) wrt the monthly cap on directional generation? EV’s suck a lot of kWh, and so if I added CT’s to my non-backup load, and the GW2 sees the consumption during say AM or midday onto my EV’s, it will dump power from PW to grid to compensate for this? But this would be at off peak times, and thus PGE will prioritize this toward my export credit limit for the month?

I really just want to see the non-backup loads in my Tesla app for visual purposes, and to have the data logged…but I think I actually don’t want it to consider those loads in its algorithm.

It seems this is the best reason for me moving both EVSE to the backed up loads side, as any draw those take off the Solar or PW will be NOT included in my monthly export cap, allowing me to utilize maximum amount of PW for time shifting TOU arbitrage.

PG&E takes the most advantageous (for them) interpretation: they remove the excess export credits from highest rate period first. I ran into this once when PG&E double-billed me by accident.

 

[power.saver]

It seems this is the best reason for me moving both EVSE to the backed up loads side, as any draw those take off the Solar or PW will be NOT included in my monthly export cap, allowing me to utilize maximum amount of PW for time shifting TOU arbitrage.

No, it doesn't matter if the EVSE is on the backup or non-backup side. If you are charging your vehicle while producing solar, it will reduce your generation by the same amount. Only what goes back through your utility meter is counted as generation.

 

[YRide]

No, it doesn't matter if the EVSE is on the backup or non-backup side. If you are charging your vehicle while producing solar, it will reduce your generation by the same amount. Only what goes back through your utility meter is counted as generation.

Ok…so non-backed up EVSE’s will reduce my solar generation amount…but backed up EVSE’s would reduce both my solar and ESS generation?

 

[holeydonut]

Ok…so non-backed up EVSE’s will reduce my solar generation amount…but backed up EVSE’s would reduce both my solar and ESS generation?

Some Scenarios:

If.......

1) the grid is operational AND it's daytime AND NON-backed-up EVSE's are behind the same electricity meter... THEN
when EVs charge, the demand of energy pulled from the grid to charge those EVs will be reduced by the solar production less whatever the rest of your home used at that time. Should there be any leftover solar energy... it'll go back across your meter and be perceived by PG&E as solar generation. should your solar energy not be enough, you'll draw energy from PG&E as consumption.

2) the grid is operational AND it's daytime AND backed-up EVSE's are behind the same electricity meter... THEN
when EVs charge, the demand of energy pulled from the grid to charge those EVs will be reduced by the solar production less whatever the rest of your home used at that time. Should there be any leftover solar energy... it'll go back across your meter and be perceived by PG&E as solar generation. should your solar energy not be enough, you'll draw energy from PG&E as consumption.

3) the grid is offline AND it's daytime AND NON-backed-up EVSE's are behind the same electricity meter... you can't charge your EV's at all. Sad.

4) the grid is offline AND it's daytime AND backed-up EVSE's are behind the same electricity meter... then when EVs charge, your EV's will either soak up all of the solar energy, or your batteries will attempt to charge/discharge to make up the difference. So you should charge your EV's wisely.

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Scenarios 1 and 2 are mostly the same, so 99% of the time it won't matter

Scenario 3 is

Scenario 4 will help you survive a prolonged zombie apocalypse

 

[evermore]

One thought I've been considering in a grid-offline scenario is that I might be okay charging the EV more slowly using the mobile connector on a smaller backed-up household circuit.

 

[jhn_]

One thought I've been considering in a grid-offline scenario is that I might be okay charging the EV more slowly using the mobile connector on a smaller backed-up household circuit.

I second this approach.