Thinking about a Powerwall 2 - help me make a decision!
First off, I have a 3.24 kW DC Enphase system (typically around 2.5 kW AC peak in the summer, but occasionally up to 3.2 kW very briefly). Also live in SDG&E territory and currently using the EV-TOU2 (whole house) rate which has off-peak rates around 20c/kWh and on-peak summer rates around 50c/kWh (currently May 1-Oct 31 from 12PM-6PM). Winter rates are only about 15% different between on/off peak, so probably doesn't make much if any financial sense to load shift then once you account for the efficiency of the Powerwall.
With the SGIP rebate at either step 2 or 3 and 6 months of time/load shifting, it seems that one might be able to get around $450/year assuming ~10 kWh/day and 30c/kWh a simple break-even period around 10 years, or the warranty period of the Powerwall.
And that's at current rates - it appears that modifications to TOU rates will move TOU time periods later in the day where storage will almost certainly be required if you want to use your solar power at peak utility rates.
None of that takes into account other non-monetary benefits of load shifting or solar self-consumption, either, or the ability to use the Powerwall for backup power (though admittedly that very rarely happens in my area).
First off, I have a 3.24 kW DC Enphase system (typically around 2.5 kW AC peak in the summer, but occasionally up to 3.2 kW very briefly). Also live in SDG&E territory and currently using the EV-TOU2 (whole house) rate which has off-peak rates around 20c/kWh and on-peak summer rates around 50c/kWh (currently May 1-Oct 31 from 12PM-6PM). Winter rates are only about 15% different between on/off peak, so probably doesn't make much if any financial sense to load shift then once you account for the efficiency of the Powerwall.
With the SGIP rebate at either step 2 or 3 and 6 months of time/load shifting, it seems that one might be able to get around $450/year assuming ~10 kWh/day and 30c/kWh a simple break-even period around 10 years, or the warranty period of the Powerwall.
And that's at current rates - it appears that modifications to TOU rates will move TOU time periods later in the day where storage will almost certainly be required if you want to use your solar power at peak utility rates.
None of that takes into account other non-monetary benefits of load shifting or solar self-consumption, either, or the ability to use the Powerwall for backup power (though admittedly that very rarely happens in my area).
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