Are solar panels on your home worth it? And did I go too far this time? Well, I’ve shared my experiences living with solar panels on my previous home for five years now. Including the pros and cons of it. I just moved into my new factory built home with the goal of achieving net zero energy, which means more solar. I’ve experienced going solar twice within five years. Both with the same solar installer, in the same state… but with very different houses. How did I go about sizing my solar panel system to try and hit that net zero target before I actually lived here? And what challenges did we run into … because there were some challenges. Hopefully you’ll find something to take away from this if you’re considering solar for yourself.
Before getting into all the details on my new setup, it’s important to hit on one important point: there’s no one-size-fits-all answer when it comes to getting solar. You really need to lay out your personal goals before wading into the solar panel waters. In my case my family’s goals were (in no particular order):
Environmental: Going all electric and removing fossil fuels from our electricity sources. We want to know where our power is coming from.
Security: Gaining some energy independence for situations like blackouts in winter storms.
Financial: We can save money on our utility bills and stabilize ongoing costs for our home. This is our forever home we built after all.
If you want to see the details on my old house, you can check out my previous videos. Overall, we decreased our reliance on the grid by around 55-60%. That equated to about $1,500 a year in savings on electricity alone. The solar panel array was actually a nice selling point for the buyer of our old house.
So what about our new house? It’s much easier to figure out how much solar you’ll need for a net zero energy home if you’re actually living in it. In order to estimate how much we’d need, I was able to learn a lot from the Span smart electric panel on our old house. I looked at the circuit data from Span to see how much we spent on electricity. This included computers, TVs, EV charging, and other things that moved over to the new house. However, I wasn’t sure about the energy needs of our new heat pump HVAC system, water heater, and appliances. It was a little apples to oranges to compare.
For all of this I had to rely on the Energy Star labels, which estimate yearly energy use and costs. For our HVAC and hot water I relied on one of the manual J estimates that a mechanical engineer put together for us. I actually had a spreadsheet calculating all this up and wanted to share it, but I’ve completely lost it. I’m not sure where I squirreled it away.
At the end of the day, I had a rough monthly average estimate we needed to hit for 100% net zero energy production over the course of a year. And no, this doesn’t mean being off grid, that was never my goal. I could go on a tangent on that, but I’m a big fan of participating in grid tied energy management solutions, like a virtual power plant for home batteries. Being a mini electricity generator for my neighborhood is appealing to me. In the dead of winter my solar production will be too low to be off grid, but in the middle of summer I’ll be producing more energy than I need. Net metering credits roll over month to month, so it will (in theory) even out over the course of the year for kWh in versus out.
The end result … we went with 43 REC Alpha 400 panels (these are 400 watts each), which means a total system size of 17.2 kW. For comparison, my old house had 26 365 watt LG panels for a total of 9.49 kW and roughly 7,000 kWh/year. This new setup is capable of producing about twice what the old one was capable of, but unlike the old one, this new house is situated better. The better angle of the panels and less shading means we’re getting better performance out of each solar panel. We have several large roof areas that face in a southern direction with no shade. And we have a small number of panels on the front of the house that face almost due west to capture some of the last light in the afternoon and evening. It’s estimated that we’ll produce almost 18,000 kWh/year (17,998 kWh to be exact). Much better performance than the old house. Averaging that out means about 1,500 kWh/month. In our old house we were using about 1,000 kWh a month. My energy use estimates for our new place put us around 1,300-1,500 kWh/month. I’m insanely curious to see how accurate, or inaccurate I was for my estimates. I’ll be putting out updates as this plays out. Based on our first month here, it’s looking pretty accurate … so far.
Since this is our forever home we went with a metal roof, which should last 50+ years and outlast the solar panels. Best part is that you don’t have to nail or screw through the metal roof to install the panels. Unless one of the carpenters working on your house accidentally drives a screw through your brand new metal roof (more on that in just a second).
Solar installers use special clamps to attach the racks and panels to the standing seams. These clamps are very easy to move, remove, replace, or update in the future. There’s no intrusion points the solar installers had to make through my roof. Metal roofs and solar panels are like peanut butter and jelly.
But yeah, I had a screw through the roof that my solar installation team spotted when they went up there to start the install. It wasn’t their fault, but someone from the team building the house. In the end it all got fixed, but it did cause some delays with the solar team since they had to steer clear of that area until the repair was done. And that happened to be the area where all of the power lines from the panels wrapped around the edge of the roof and into the garage. Good times. The solar crew took it in stride though, which was great.
But that’s just the panels. Each panel has an Enphase IQ8 Plus microinverter underneath. The microinverter changes DC electricity to AC and sends it to the central brain. From there, it goes to a battery and into the house. The other reason I went Enphase specifically was because of the peanut butter and chocolate combo you get with their battery system. I don’t know why I have such a peanut butter craving right now.
When I finally get the batteries installed, the system will be able to load balance itself during a blackout. Basically, a battery can only take so much energy at once, which you see referred to as continuous power. For instance a Tesla Powerwall has a continuous power rating of 11.5 kW, which means in theory that you can’t push more than 11.5 kW out at once or in at once. If your solar panels are generating 20 kW of electricity, the battery can’t handle all the power. If the excess power can’t be used or sent to the grid, the system has to be shut off. Typically, the system’s controller turns the solar panel array on and off. This helps control the amount of power going into the battery. In a blackout or off-grid condition that means you’re losing a lot of potential power. Well, the Enphase system can intelligently dial back individual panels to hit a load that can be used by the house and battery system. Less wasted potential power.
Their system can even be configured in a similar fashion without a battery installed at all, which is HUGE! If the power goes out and you don’t have a battery system, your solar panel array will shut off for the safety of grid workers. Well, with the Enphase system, the system will disconnect from the grid as normal in a blackout, but it can keep running locally. It dials back the number of individual panels producing electricity based on the current power draw in the house. It’s really slick. Hopefully that doesn’t sound like an Enphase ad … I’m not affiliated with them in any way. I’m just very impressed by the system and paid for this myself.
So what about the cost of the system? Well, the new system cost $55,384, which yes … is pricey. The cost of installing solar is hyper local, so it may be cheaper in your area. You can pop your eyes back in your head now. I mentioned this in an earlier video, but I financed the install through Atmos Financial, which was a sponsor in that video for full transparency. They had a great interest rate and lower fees than most other banks. I’ll most likely be paying that loan off very quickly to save on the total interest paid. Most homeowners pay off their loans within 6-7 years, which I actually did on my last house. It’ll be the same this time too. It also didn’t hurt that Atmos is focused on funding clean energy projects, so customers who bank there are helping to invest in the future of clean energy. It’s a closed-loop, completely climate-positive banking option, which I love about it. I’ll put a link in the description if you’re interested.
The Federal solar tax credit is 30%, which means my wife and I can reduce our tax burden this year by $16,600. This knocks the out of pocket costs down to $38,784. The estimate is that by around year 7, we’ll hit net positive with the system and start seeing the financial benefits of production. But there’s also some additional state incentives that we’ll be able to take advantage of to knock those out of pocket costs down further.
We’re also getting batteries installed for this system in a matter of weeks, but I’ll be getting into the details of that in a separate video. This will affect the incentives I qualify for. For example, my solar panels will be eligible for a Class 1 REC program in Massachusetts. REC stands for Renewable Energy Credit, which is a broader type of credit compared to a Solar Renewable Energy Credit (SREC). That’s what I had on my previous house. It’s similar, but different. Right now the program pays out an average 3.5 cents per kWh generated. If I produce the estimated 18,000 kWh a year, that means I’ll get paid out roughly $630 a year. The credits are sold at market rates, so the amount will fluctuate making it hard to estimate. For back of the napkin math, I’m assuming I’ll see somewhere between $500-$600.
The battery system I’m getting installed will be participating in the Connected Solutions virtual power plant program, much like my last house. The grid will be able to tap into my battery storage to help with peak shaving during high demand events during the summer. Then at the end of the year they pay you for that use. I’ve got a whole video about that and will go into more detail on my battery setup once it’s done.
But no project is perfect or goes according to plan 100%. A screw through the roof would surprise anyone, but I’m not talking about that. Here in the US it’s kind of the wild west when it comes to solar panel regulations on people’s homes. There isn’t one standard set of regulations in the industry, causing a crazy mix of incentives and rules. It’s why there’s an unfortunately large number of shady companies selling bad solar out there. My solar company was surprised by the local regulations in my town that they didn’t know about. They have a ton of experience elsewhere in Massachusetts, but every town is different. They were at the final stages, with a handful of panels left to put up, when they found out they needed a rough-in inspection so the town inspector could see all the junction points beneath key areas of the system before the panels went up. That meant they had to take down a bunch of panels, get the rough-in inspection, and then put them all back up. And then get the final inspection after that. The solar team were good sports about it, but it is a problem that requirements vary so much between towns. The more this can be standardized, the more it can help installers streamline the process, speed up installs and hopefully save on costs.
So at the end of the day, I think I did a pretty good job trying to estimate what my new home’s energy needs will be, but the jury is still very much out on that. We might want to start a betting pool to see who comes closest. Would I have done anything differently? Not for the design of the system, but I would have made some different choices during the build process. I talked about this in my “Net Zero Regrets” video, but there were some communication issues between the different teams working on my house. Ideally, I would have had all of the conduit runs preinstalled in the attic and through the roof before the solar installers ever showed up. But because of the communications breakdowns that window closed and we had to move forward without doing any of that work. The end result still looks good to my wife and I, so it all worked out in the end.
No matter how close I get to my net zero energy goal, I’ve pre-paid for 18,000 kWh of energy each year. This will save me a lot of money in the future. It ticks those three goals I brought up at the beginning. But your goals might be different from mine.