One year ago, our solar power system installation was interconnected to the grid after it received its final approval from the local inspector and the utility. I’m commemorating this one-year anniversary with a look back and a report on how things went and what we learned.
Early Failure
Our solar power system uses power from 21 solar panels, each capable of producing more than 400 watts. The power is carried from the roof panels to the inverter via two sets of cables, giving us two “strings” of panels. One string has 10 panels; the other has 11.
In mid-August, about six weeks after we went live, half the panels stopped producing power. (Actually, they were still working, but power was no longer reaching the inverter.) After some back and forth with our solar provider, they honored the warranty and scheduled repair for September 30. (We first had to convince them the problem wasn’t shade, squirrels, or our imagination.) During the six-week delay between the failure and the repair, we were producing only half the power we should have been. It was inconvenient, and it meant we weren’t saving as much money as we should have, but it wasn’t an enormous problem because we could still access grid power.
Hurricane Helene hit on Sept. 27. That not only prevented repairs, it knocked out grid power. So while we had power, it was half the power it should half been. We limped along for more than two weeks before the crew could get up here and repair our system. The problem? One faulty connection had shorted out. Once they showed up, it was repaired in less than half an hour.
Lesson: Like a new car, your system is only as good as the guys who built it. So, expect to uncover some problems with your solar power system early on.
Lesson: If I had done this as a DIY install, I might have been able to fix it myself. Of course, there may have been far more points of failure, and I would have had to file all the paperwork for permits and utility approval. In the end, I believe the benefits of hiring professionals outweighed the costs.
Winter Performance
We didn’t realize how much difference there is in sunlight and power generation between the summer and winter until we saw the data on our app. In December, we produced 550 kilowatt-hours (kWh). In June, we produced 1180, more than twice as much.
We had to pay for power in the winter, but we made a profit in the summer by selling power back to the utility. Our bills ran from a winter high of about $75 to a summer low of negative $92. During the spring and fall, the bills ranged from -$18 to +$20. Over the course of the year, our net savings was about $2,000. As electricity prices rise, we expect our savings will increase.
Lesson: If you are using a solar power system off-grid with no interconnection, your system will need to be double-sized or you will run out of power November through February. (The further north you are, the worse it will be.) However, if you double its production capacity, you will have huge amounts of extra power in the summer, especially May through August. So you might as well have air conditioning to burn some of that excess power.
Nameplate Capacity
Our system has a theoretical maximum production of 8,500 watts on a bright sunny day. This has never happened, in part because the panels face two different directions but also because of clouds, rain, fog and other bad weather, meaning our normal max production is between 7,500 and 7,800 watts. There are also losses every time you convert from AC to DC or vice versa. Just running the equipment also eats up a few watts.
Our average daily power usage is around 30 kWh. Our panels can produce that in about 4 hours. Extra power is used to run the house, recharge the batteries, or is sold back to the utility, in that order.
Over the course of a year, we produced and used almost the same amount of power, 10,800 kWh, about 11 megawatts. If the system hadn’t been working at half power for six weeks, we would have produced several hundred more kWh than we consumed. I guess that means our system is sized correctly.
Lesson: If you need to generate X amount of power, design your system to have 15 to 20 percent more than X. Having too little power is a far greater problem than having too much.
Power Outages
We bought the solar power system because we wanted backup power during our frequent power outages. We initially got a quote for a whole-house generator, but the cost was so high, we decided to spend a bit more and get solar. That way, there was no propane to run out and no noise from the generator. As a prepper, the idea of not needing to buy propane was appealing.
Our system reports we had 63 power outages, resulting in more than 550 hours without power in the past year. That includes the three-week outage during Helene. Most of these outages lasted less than an hour, with many under 15 minutes, but we also had numerous two-to eight-hour blackouts. During these outages, the backup batteries and solar panels powered the house. In only one case did the system fail, and this was when our electric heat kicked on. It drew more power than the batteries could provide. I flipped that breaker off, and the system rebooted and performed just fine for the rest of the outage. I also threw a few more logs into the wood stove to keep us warm.
Lesson: If more than half your neighbors have a whole-house generator, you probably live in an area with an unreliable power grid. (A downside of rural living.) We tried to deal with this with UPS batteries on our computers and TVCs and a 3,500-watt generator, but a system that automatically kicks in is a real convenience.
Lesson: If you have solar, you need gas heat or a wood stove because electric heat is an electricity hog.
Modern Technology
Our Franklin WH A-gate has several advanced features and allows me to change how it performs by using an app on my phone. For example, if we expect a storm, I can set the system to “emergency backup” and it will import 10 kWh from the grid until the batteries are fully charged. That gives us maximum backup power in an outage.
We have also programmed our system to cut off the hot water heater and HVAC when the battery’s state of charge drops below 70 and 80 percent, respectively. This reserves the bulk of our power for important things like refrigeration, food prep, and lighting.
The app also can set the system up for time-of-use management. This means we can buy grid electricity only when it is cheap and rely on the batteries when prices are high.
The apps also track the data, including those numbers I am relaying to you, and give use many ways to analyze our data and optimize the system. If we have a problem, the manufacturer and installer can see the data from our app and possibly diagnose the problem remotely. The downside is we lose many of its features if the internet is down. In that scenario, I can connect the app directly to the system’s brain via Bluetooth and change settings. It gives me control, but fewer bells and whistles.
Lesson: If you are living off-grid and have limited internet connectivity, look for a system with a screen or similar interface on the inverter rather than an app.
Lesson: As utilities institute time-of-use rate plans to encourage people to minimize electric usage during peak demand, having a battery backup can offer significant cost savings.
Overall Satisfaction
Would we do this again? Hell yes. We got through 61 of the 63 power outages without a single problem. That alone would be reason enough. The fragile state of our electrical grid and the rising prices are two other solid reasons.
There’s an article or video every week about how the country won’t be able to produce enough electricity to power the coming AI boom. Companies are looking at everything from nuclear power to diesel generators to produce their own power to run their AI data centers. I believe demand and reliance on renewable power means America will see more blackouts and brownouts caused by a lack of electrical power generation and distribution capabilities. That will make having our own source of electrical generating capacity and power storage even more important.
Don’t get me wrong. There were hiccups along the way. If you were reading the blog during installation, you may remember that a surge during testing knocked out both our oven and HVAC. The HVAC repair was simple, but the oven had to be replaced. (Our installer paid for both.) Things haven’t been perfect, but they’ve been pretty darn good. The system has been running without a hitch since November, knock on wood.
Lesson: In our experience, installing a whole-house solar power generating system with lithium iron phosphate backup batteries (the kind that won’t combust into a runaway fire) is worth the investment. Besides giving us “free” power, it gives us peace of mind and boosts our preparedness level.
