I have been operating my two PW2 in time-based control lately with a 20% reserve and that works well in terms of getting a full charge from the solar if there is some reasonable amount of sun in the morning, and powering the house during peak pricing in the afternoon/evening. When I anticipate the possibility of a power failure, I typically up my reserve accordingly.
About 4 this morning, however, we had an unanticipated power failure and the PW2 started powering the house with the 20% of the battery left in the reserve. (I got a message on my phone at that time saying that the PW was powering the house at 89% State of Charge??). As the geothermal system started to warm up the house shortly thereafter, the PW2s ran themselves down to 5% and shut down and my generator automatically started up. About an hour later, the PW2 started putting out power again and the generator automatically switched off allowing the PW2, now at 4% SOC, to power the house. Knowing that 4% would not last long, I manually switched to generator operation.
When the generator is powering the house, the PW2 can still “see” and charge from solar, but only if it puts out a voltage and frequency that the solar inverters can use to sync. I have seen this work in the past, but not this time. At first the Tesla app showed the PW2 in backup mode, but since it was still dark there was no solar. After a while the PW2 went into standby mode and so even after the sun came up and the solar was capable to generating power to charge the PW2, the solar inverters did not see a voltage from the PW2 with which to sync, and so the inverters stayed in wait and try again mode.
How to wake up the PW2 and get it putting out a feeler voltage to get the solar going was then the question? I tried switching operational modes several time and finally, for whatever reason the PW2 went into backup mode. Progress, I thought, but even then, the solar inverters still did not see any voltage from the PW2 with which to sync. Frustrating. Soon thereafter however, the grid came back on, the solar started up and the PW2s started charging.
Since I have seen the PW2 charging from solar in the past with the generator powering the house, I don’t know why this was different and also what is the best way to wake up the PW2 so that it starts putting out a feeler voltage to get the solar going. Perhaps it was the low, <5%, SOC?
About 4 this morning, however, we had an unanticipated power failure and the PW2 started powering the house with the 20% of the battery left in the reserve. (I got a message on my phone at that time saying that the PW was powering the house at 89% State of Charge??). As the geothermal system started to warm up the house shortly thereafter, the PW2s ran themselves down to 5% and shut down and my generator automatically started up. About an hour later, the PW2 started putting out power again and the generator automatically switched off allowing the PW2, now at 4% SOC, to power the house. Knowing that 4% would not last long, I manually switched to generator operation.
When the generator is powering the house, the PW2 can still “see” and charge from solar, but only if it puts out a voltage and frequency that the solar inverters can use to sync. I have seen this work in the past, but not this time. At first the Tesla app showed the PW2 in backup mode, but since it was still dark there was no solar. After a while the PW2 went into standby mode and so even after the sun came up and the solar was capable to generating power to charge the PW2, the solar inverters did not see a voltage from the PW2 with which to sync, and so the inverters stayed in wait and try again mode.
How to wake up the PW2 and get it putting out a feeler voltage to get the solar going was then the question? I tried switching operational modes several time and finally, for whatever reason the PW2 went into backup mode. Progress, I thought, but even then, the solar inverters still did not see any voltage from the PW2 with which to sync. Frustrating. Soon thereafter however, the grid came back on, the solar started up and the PW2s started charging.
Since I have seen the PW2 charging from solar in the past with the generator powering the house, I don’t know why this was different and also what is the best way to wake up the PW2 so that it starts putting out a feeler voltage to get the solar going. Perhaps it was the low, <5%, SOC?