My setup is 2 Powerwall 2’s paired with 20 solar Enphase inverters putting out continuous 4.3 kW of AC. I had them installed in April and they’ve been working great. I’m with a local municipal utility in CA and I’m still grid connected. After installation was complete and also days after I tested the battery backup mode and solar charging capability, the batteries would take over flawlessly when I disconnected from the grid through the main breaker.
Side story here. My utility is, to put it mildly, anti-solar. They’ve changed the rates fairly recently to their version of NEM 2.0. They’re also pretty adamant the rates can change anytime in the future to make your solar investment even less worthy in the future. This basically punishes those who go solar since they added a demand charge and also any excess is credited at paltry wholesale rates which is anywhere from under 1 cent a kWh to at most 4 cents per kWh (the highest credited rate I saw last year). This is on top of the fact that any excess I consume is billed at retail rate: 10 cents off peak to 15 cents on peak. This is the main reason I went with Powerwalls: to not get hosed on demand charges and to avoid giving away excess power generated for peanuts.
The issue I’m having is that with plenty of solar generation I’m getting this small power drain from the grid. For this month of May I’ve used 6.4 kWh in total from the grid according to the Tesla app. I also check my instantaneous demand on the app and I’ve seen spikes where it goes to 0.1 or 0.2 kW of demand for an instant on a rare occasion. My utility provided meter confirms this too since for the month of May I’ve registered a maximum demand of 0.23 kW. I realize I’m bickering over pennies but shouldn’t the Powerwall register 0 kW of grid power if I’ve never discharged the batteries completely? Same with energy use: shouldn’t I see 0 kWh of use since I’ve never had the batteries anywhere near being discharged? The lowest I’ve gone down to is like 45% since I installed them back in April. I’m just trying to pinpoint where this vampire drain is coming from since I know the batteries coupled with solar can run without grid power. I also generate more than enough to charge batteries and for the home daily consumption.
Shouldn’t the gateway be disconnected from the grid at all times when there is either enough battery power or solar or a combination of both of them? Are the batteries pinging the grid periodically to reference frequency? Not familiar with the specific switching or inversion scheme on the gateway or batteries but is there any small consumption of grid power going on here for gate currents to drive switching? I’m just trying to figure out how this small power drain from the grid is happening.
Side story here. My utility is, to put it mildly, anti-solar. They’ve changed the rates fairly recently to their version of NEM 2.0. They’re also pretty adamant the rates can change anytime in the future to make your solar investment even less worthy in the future. This basically punishes those who go solar since they added a demand charge and also any excess is credited at paltry wholesale rates which is anywhere from under 1 cent a kWh to at most 4 cents per kWh (the highest credited rate I saw last year). This is on top of the fact that any excess I consume is billed at retail rate: 10 cents off peak to 15 cents on peak. This is the main reason I went with Powerwalls: to not get hosed on demand charges and to avoid giving away excess power generated for peanuts.
The issue I’m having is that with plenty of solar generation I’m getting this small power drain from the grid. For this month of May I’ve used 6.4 kWh in total from the grid according to the Tesla app. I also check my instantaneous demand on the app and I’ve seen spikes where it goes to 0.1 or 0.2 kW of demand for an instant on a rare occasion. My utility provided meter confirms this too since for the month of May I’ve registered a maximum demand of 0.23 kW. I realize I’m bickering over pennies but shouldn’t the Powerwall register 0 kW of grid power if I’ve never discharged the batteries completely? Same with energy use: shouldn’t I see 0 kWh of use since I’ve never had the batteries anywhere near being discharged? The lowest I’ve gone down to is like 45% since I installed them back in April. I’m just trying to pinpoint where this vampire drain is coming from since I know the batteries coupled with solar can run without grid power. I also generate more than enough to charge batteries and for the home daily consumption.
Shouldn’t the gateway be disconnected from the grid at all times when there is either enough battery power or solar or a combination of both of them? Are the batteries pinging the grid periodically to reference frequency? Not familiar with the specific switching or inversion scheme on the gateway or batteries but is there any small consumption of grid power going on here for gate currents to drive switching? I’m just trying to figure out how this small power drain from the grid is happening.