Solar Panels For Home - 9 Months Later
It’s the video many of you have been asking for for some time now. Ever since I published the video about my solar panel system on my home earlier in the year, and my experience with the installation and energy production I’ve been seeing, I’ve been asked for an update on how it’s going. By a lot of people. Well, it’s time. How much energy production have I been seeing? How much money have I spent versus how much I’ve saved? I’m going to cover it all.
I had my solar panels installed in September of 2018 and turned on at the beginning of October. It was a long and drawn out process, but pretty straight forward. You can check out my previous solar panel video for details around that experience.
On that video, as well as my videos on energy storage, I’ve gotten a lot of comments about how solar isn’t worth it because you’re not getting energy on cloudy days, when it’s snowing, or can’t live off-grid and it only works in certain locations. There’s usually a nugget of truth in those comments, but they all miss the bigger picture for why solar works for so many people.
For me specifically … I live near Boston, so knew going in that my solar production during the winter months would be less than ideal. My home and the surrounding environment is also a bit challenging with trees blocking the late afternoon and early evening sun. My goal has never been to be 100% on solar. For my specific situation that’s not possible, but it might be for many others. My goal is to get as much energy as I can from a renewable and sustainable resource; to reduce my carbon footprint as much as I can; and do it in a financially responsible way that works for me. So have I been achieving that goal? The jury is still out, but things look like they’re on the right track.
It was a little anti-climactic turning on my solar panels for the first time since it was a rainy day in October. I also knew whatever I saw that month was only going to drop the following month since we were heading into winter. My system is managed by Enphase, which has an “okay” app for checking high level data for day-to-day production. The way my system is set up, I don’t see down-to-the-minute production numbers, but that hasn’t bothered me too much because I also have a Sense energy monitor installed. I have a video on the Sense, too, if you’d like to see more on how it works and my experiences with it, but it’s a pretty cool system that lets me see real time data for my home energy use and solar panel production. Between the two I have some great data for comparison along side my electric bill.
One of the common topics that’s come up in a lot of comments is the cost of maintenance. It’s still early days, but so far my cost has been … zero. That’s not to say there’s been no upkeep on the system, but I haven’t had to pay anything out of pocket to keep the system up and running.
Over the winter we had a number of good snow storms that dumped a lot of snow on the roof. What I found was that light snow typically didn’t stick to the panels at all and melted away almost as fast as it landed on the panels. Heavier snow would accumulate just like a roof without panels though. If the sun came out within the next day or two, we’d often find mini avalanches of snow as the panels cleared themselves. Our roof was clear far sooner than my neighbors without panels. A few times I pulled out a roof rake to clear off the panels quickly to try and maximize our solar production, especially if the sun was shining again after the storm. I have a small house and can reach about 90% of the panels from the ground with my roof rake. It took about 15-20 minutes to clear everything off, so wasn’t too much of a chore. (Shoveling away the snow that fell is another story…)
In the warmer months you’ll notice pollen and dust buildup if it hasn’t rained in a while. If it gets really coated, you might start to see a minor hit to energy production efficiency, but I haven’t. In my area it’s rained frequently enough that I haven’t had do any manual cleaning. I did it once to see how difficult it would be, but all it took was a quick spray from a garden hose. To be more water efficient I bought an attachment for my roof rake that has a mop and squeegee head. I still haven’t had to use it though.
We did have two separate incidents where the solar panels stopped producing electricity, which was throwing errors in the Enphase system. My solar installer came out right away and determined that my AC disconnect switch was malfunctioning. The first time out they switched everything off and on again to get it working. The second time out they ended up replacing the faulty switch and everything has been working perfectly since.
Looking at the energy production from the beginning of October, you can see a clear trend. My solar production starts at around 250 kWh for October, but quickly drops to a low of about 100 kWh in December. This low period continued through February, but more startling is when you look at the production numbers against the consumption numbers. We’re typically using between 700 - 1000 kWh per month. And before anyone says anything in the comments, yes that’s high, but it’s not out of line for the average home in the United States. Energy conservation is as important as clean energy production, but that’s a separate video.
To say that I was excited to see how my production would take an upswing in the spring would be an understatement. I was like a kid eagerly awaiting Christmas morning for my Red Ryder Carbine-Action Two-Hundred-Shot Range Model Air Rifle. March is when everything took a sudden turn with production hitting around 670 kWh, which meant March covered two-thirds of our energy use. Step into April and May and things stayed fairly consistent for production. Since April we’ve been meeting or exceeding our energy use from our solar panels.
For me the highlight was when my wife couldn’t stop laughing when she opened the April electric bill and saw that we owed $10.94. Compare that to the previous year at $233.40 … you can probably understand why she was laughing. Our June bill is the first one with a credit of $38.36 on our account, which most likely means we won’t have a bill to pay in July, either.
If you step back you’ll see a sine wave pattern emerging for our solar production, which means I can provide a pretty good estimate for what the rest of the summer and early fall will look like. Depending on how it plays out over July through the beginning of October, it’s looking like we may come in around the low 6,000 kWh range for the year. The estimate we received from our installer was 6,615 kWh for the first year, so I think we’re going to fall a little shy of the estimate. If that turns out to be the case, it’ll be disappointing, but not a showstopper … and it’s also only half the story.
For the other half of the story we need to look at the money. Here’s a look at our electric bill’s kWh over time. All the way through 2018 up until June. Across the board you can see that we’ve done better, especially once you hit March. For the actual electric bill price it looks very similar. The delta between what we’ve paid in the past spring and summer vs. what we’re paying now is substantial.
Just in electricity costs we’ve seen $929 in savings from the previous year, which accounts for a 48% drop from before solar panels ($1919). But if you want a truer apples to apples price, it’s easy to calculate the price per kWh the panels have been generating. Just take the cost per kWh and multiply that by the kWh’s the system has been producing. Since we’re on full net metering, we’re getting full credit for all of the solar power we’re using or putting back into the grid. That’s $873 so far.
When you add in the SREC program, which are credits paid out for how much electricity you put back into the grid, that adds another $1,136 on top of that. We have a 10 year solar loan that has had a minimum payment for the first year of $148 a month, but we didn’t start paying for that until December. If we retroactively roll those payments back for October and November, you’d be looking at $1,332 in loan payments for the same time period.
That’s a lot of numbers I just threw at you, so let’s break this down at a high level. That’s $873 in solar production, plus $1,136 for SRECs, minus $1,332 in loan payments. We end up positive by $677 so far. If we didn’t have SRECs, we’d be $-459. Would that mean it’s not worth it? For me, no. Paying the minimum on the solar loan will pay it off in 10 years, but we’re not doing that. We’ve actually been overpaying the loan already to get it paid off earlier than 10 years. That will reduce the loan interest we’re having to pay and help the solar panels hit break even sooner. The solar panels are warrantied for 25 years, but can be expected to work well beyond that timeframe as well.
So again, even without SRECs the system would hit break even and turn a little profit before its true end of life. And as much as people like to hold up incentive programs and subsidies as to why solar panels don’t work, we do have them. Once you put those numbers back into play, you can see that we’re actually getting money back from our system today even with our minimum loan payment. That means our out of pocket costs for the system are close to a wash for the loan payback period right now. Our loan payment and electric bill are balanced out with the solar energy production and SREC credits across the past nine months, and that should hold true for the year.
So what about the system turning a profit? What is the payback period? Like I’ve said before, it’s still a little early to tell for sure because I’d like to have at least one year of data for that. However, filling in the blanks for those few months we’re missing, here’s how it’s looking right now.
Our system cost $29,609 for a 9.49 kW system made up of 26 LG 365 watt panels. In my previous video I had said we were going to get a $9,883 tax credit, but that was a typo. It should have been an $8,883 tax credit. Once we got that credit back on our tax refund we immediately applied it to the solar panel loan, which knocked the final amount we’re paying off to $20,726. Depending on the rate we pay off the loan it could be close $6,800 in interest over 10 years, which is why we’re paying it off faster to reduce that amount. For the sake of the numbers here, I’ll keep that interest in here for a total of $27,526 on the loan.1
We’re getting $126.22 a month in SREC credits for 10 years, so we’ll be seeing $15,146 from that. That leaves us on the hook for $12,380 out of pocket. But then you have to look at the money we’re saving on our electric bill. We were spending about $2,600 a year on electricity, but will most likely be spending about $1,100. That’s a savings of $1,500 in the first year.
If we assumed that electricity prices won’t increase (they will) and my panels will produce the exact same amount for those 10 years (they won’t), then I’d be looking at $15,000 in savings over the first 10 years. That would mean the solar panels will have reached their payback period in about 8 years, which is right in the ballpark of what we calculated before having them installed. Yes, there is variability in there because of the cost of electricity and reduced panel efficiency over time, but I’m putting that to the side for simplicity. In reality, I don’t think it’s going to change that prediction much at all.
In the U.S. electricity prices have risen by 15% over the past 10 years,2 which is about $0.02 per kWh per year. But that varies depending on the region. In my area specifically, prices have increased 10% in the past 10 years. And under my panel warranty, they’re guaranteed to produce at least 88.4% of their original efficiency, which means you’re talking about a .5% drop each year. If anything, I’m going to see the cash amount saved in electricity increase each year because of how quickly the electricity prices are rising … not a drop because of a minor decrease in panel efficiency.
Again, depending on the cost of electricity and without the SREC credits, I’d be looking at a payback period closer to 13 years (not including interest). And if I also didn’t have the tax credit, I’d be looking at closer to 18 years. No matter how I sliced the numbers, I always came out with my specific solar panel installation earning it’s money back before the system’s end of life.
So have I achieved my goal to get as much energy as I can from a renewable and sustainable resource? To reduce my carbon footprint as much as I can and do it in a financially responsible way that works for me? Yes. Financially right now we’re in the same month to month position as we were before solar panels, but we’re getting the benefit of reducing our dependence on fossil fuels for our energy use. In another 8 years or so we should have the system completely paid off and turning a tidy little profit for us going forward. So far, so good … but I’ll be keeping a close eye on my system and how it’s holding to those predictions over time. I don’t anticipate any maintenance costs to throw this off by too much either, but time will tell.
Now, if you’re interested in going solar, I strongly recommend checking out EnergySage for research and articles, which is a completely free service. They have great write-ups and reviews of different solar panels, inverters, and solar tech that can be useful no matter where you live. But if you live in the U.S. and are interested in going solar, you can get quotes from installers by using my Energysage portal. You can plug in your information and request quotes from solar installers, which all get funneled into your EnergySage account. You don’t have to worry about getting flooded with phone calls. It makes it easy to compare installers, cost estimates and energy production quotes in one place. And installers also have customer rankings and feedback, so you can find a reputable and good quality installer. I’ve used it myself and can vouch for how well it helped me through the process.
1: Nice loan calculator: https://calculator.me/loan/