We recently had our first extended power outage since installing the solar system almost a year ago. Nothing major, just an evening blackout after a windstorm came through. But it was a great test of the backup system.
The lights went off suddenly before supper but we were able to have a couple of lights on using the backup circuit (essentially one 15A circuit with 3 live wall outlets). It was a relief not to have to think about potentially losing any food in the frig. or freezer, which kept humming right along. We were even able to stream a video that night for a little family entertainment–makes it easy to forget there’s a power outage. Guess the days of gathering candles and flashlights and jealously guarding the frig. door from careless opening are long gone.
One big question, of course, is how long would our battery bank’s reserve capacity last? The house ran on backup for 4 hours, roughly 5-9pm, probably the most power-consumptive time of the day. All told, the battery bank was drawn down to 92%. From that I would estimate we could last roughly 1-2 days, possibly more if were careful. Ideally, you don’t want to draw the bank down past 50%.
In the morning, the sun recharged the bank fully well before noon in full sun. With an overcast sky, it probably would’ve taken most of the day.
When I walked outside during the evening to dump the compost, I heard our neighbor’s gasoline generator chugging away. While I still think we should get one just for backup, it’s sure nice to have a quiet bank of batteries to draw on instead of a noisy, stinky generator.