Solar update
Aug. 29th, 2022 04:01 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
elizillaWhen last I posted, our rooftop solar had gone live, except for the net metering. Later that evening we got access to the monitoring app. Since it’s new, I have been watching it obsessively, of course. It is a little weird to look at. It plots solar production, and consumption. It breaks total consumption into grid consumption vs self consumption. It’s kind of confusing because self consumption can come from the battery, like, at night, but it’s plotted on top of the production graph. There’s a separate graph for the battery state of charge. Most days, the battery hits 100% by noon. After the sun goes down, it declines by a couple percent each hour. Most days, it doesn’t drop below about 75% before the solar comes on again. Of course it’s summer, I know it won’t look this great in winter, but so far I am very pleased.
We don’t actually know how high the production can go, since it clips off when the battery is full and we normally aren’t using anywhere near what it can do. So our graphs show a sharp peak around noon, then drop to almost nothing. I wanted to see the peak of the bell curve so I started focusing on car charging. When the solar went live our car happened to be fully charged, and we weren’t going anywhere. It was several days before we drove out to my folks house and came back ready to charge. In the dark, of course.
The next day we waited until the house battery filled up, then we plugged in our L2 charger. That evening we checked and it had charged the car from the grid! Argh! Why?
Next day, I didn’t check until late afternoon. At which point I discovered the system had done nothing since we plugged in the car. No production, and the battery hadn’t been used overnight, it was sitting at 98%, unused. We called the company and someone came out that evening to fix it. We had an “arc fault”. This is not unusual, apparently, and they showed us how to reset the system and start it going again. These arcs are apparently a background noise threshold and there is a setting they can dial up and down. If it continues causing trouble they will adjust it.
We charged the car again a few days later. No errors this time. But, it sucked the house battery down then started hitting the grid again. The solar hadn’t stopped. It’s just, the level 2 charger runs at 7500 watts, and the solar was only producing about half that. If we want to charge the car entirely from solar, with our size system, we need to slow down the charge. Which we can do. There are fancier level 2 chargers that automatically manipulate the charge speed to preferentially use solar but ours does not have that feature. I don’t think it’s worth changing our charger now. But I can be more strategic as I get the hang of it.
Today, DTE was here to fix our meter, and we began selling power back about ten minutes ago. Today is also the first time it’s been hot enough to run AC, since we got the solar. And, it’s cloudy. Even with the cloud cover and the AC cranked, more power is flowing out to DTE than we are using here. Of course this is the peak time of day.
All this sounds like a lot of work and fussing. But it’s mostly just fussing because that’s how I am. The solar company monitors it, they would have caught that failure, I just caught it first because I am being OCD. The system makes no sound and requires no maintenance. It already feels like free electricity. I can crank the heck out of the AC and there won’t be a bill to pay. I just love it!
We have sent 1.2 kWh back to DTE while I typed this. That’s about ten cents. But still it’s awesome to do it at all!
We don’t actually know how high the production can go, since it clips off when the battery is full and we normally aren’t using anywhere near what it can do. So our graphs show a sharp peak around noon, then drop to almost nothing. I wanted to see the peak of the bell curve so I started focusing on car charging. When the solar went live our car happened to be fully charged, and we weren’t going anywhere. It was several days before we drove out to my folks house and came back ready to charge. In the dark, of course.
The next day we waited until the house battery filled up, then we plugged in our L2 charger. That evening we checked and it had charged the car from the grid! Argh! Why?
Next day, I didn’t check until late afternoon. At which point I discovered the system had done nothing since we plugged in the car. No production, and the battery hadn’t been used overnight, it was sitting at 98%, unused. We called the company and someone came out that evening to fix it. We had an “arc fault”. This is not unusual, apparently, and they showed us how to reset the system and start it going again. These arcs are apparently a background noise threshold and there is a setting they can dial up and down. If it continues causing trouble they will adjust it.
We charged the car again a few days later. No errors this time. But, it sucked the house battery down then started hitting the grid again. The solar hadn’t stopped. It’s just, the level 2 charger runs at 7500 watts, and the solar was only producing about half that. If we want to charge the car entirely from solar, with our size system, we need to slow down the charge. Which we can do. There are fancier level 2 chargers that automatically manipulate the charge speed to preferentially use solar but ours does not have that feature. I don’t think it’s worth changing our charger now. But I can be more strategic as I get the hang of it.
Today, DTE was here to fix our meter, and we began selling power back about ten minutes ago. Today is also the first time it’s been hot enough to run AC, since we got the solar. And, it’s cloudy. Even with the cloud cover and the AC cranked, more power is flowing out to DTE than we are using here. Of course this is the peak time of day.
All this sounds like a lot of work and fussing. But it’s mostly just fussing because that’s how I am. The solar company monitors it, they would have caught that failure, I just caught it first because I am being OCD. The system makes no sound and requires no maintenance. It already feels like free electricity. I can crank the heck out of the AC and there won’t be a bill to pay. I just love it!
We have sent 1.2 kWh back to DTE while I typed this. That’s about ten cents. But still it’s awesome to do it at all!
