Deep Dive on REC Alpha Pure Black Solar Panels
Breakdown on my new power producers...
In going back through my previous posts I realized I never went into detail on the model of solar panel being installed on my house. The Pure Black 400WP from REC Alpha is what we’ve ended up going with, and while it wasn’t my first choice, nor my installer’s first choice, there are one or two things I like more than the original selection.
Solar panels are available in a ton of different sizes and power output capabilities, though at the end of the day I think I can speak for just about everyone when I say “they’ll have generated enough power when they generate more”. Mainstream solar panels generate power with an efficiency that hovers around 20% with some very small variation depending on the panel materials and cell design. Supposedly laboratories have developed a solar cell with near 40% efficiency, but that’s a topic for another time.
My solar installer recommended 400W panels for my house given my power requirements and available surface area on my roof (including the pergola being built). While there are panels of higher output, based on current panel designs those would be somewhat prohibitively large which would lead to layout issues and possibly the need for a second model of panel. When it comes to residential installations aesthetics counts for a lot and using mismatched panels to maximize the potential power generation just looks plain ugly. That and the panel rigging would have to be laid out differently for each model of panel. Just plain messy if you ask me. And if you have a spaghetti monster of wiring in your array, that’s just begging for trouble in the long term.
The original model chosen was the Solaria PowerXT 400, however delays in the pergola construction resulted in a late ordering of the solar panels and rigging, which meant these panels were no longer available. I was told that somebody placed an ENORMOUS order with Solaria that would take until the end of Quarter 1 next year (2023) to fulfill. I immediately don’t like this person. Solaria makes a beautiful all black solar panel and the PowerXT 400 has a very nice power density, allowing it to generate 400W of power at peak output with a smaller form factor. Considering space on my house roof is effectively a premium due to the roof lines and large dormers, this was an ideal choice.
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However, this was not meant to be. After my solar engineer made some inquiries three options for manufacturer presented themselves: Solarever USA, Meyer Burger, and REC Alpha. REC Alpha was what we ultimately chose.
Solarever USA makes a 400W black panel just like Solaria but in a slightly bigger form factor. The warranties are also the same. What ended up killing this option was a second phone call from my solar engineer saying that his own company couldn’t honor the warranty because the company was so new. Or at least that’s what I’m remembering as that conversation was several months ago. I could be wrong about that.
Meyer Burger had some potential since at least there were no issues (that I was made aware of) when it came to ordering the panels or warranty honoring. The technology was sound, the performance over time was the same as Solaria and Solarever USA and the warranty was actually a little bit longer. However these panels are only rated to produce between 375 and 395W, making them fall just short of producing the same amount as the others, and that’s where REC Alpha took the lead.
REC Alpha’s Pure 405AA solar panel produces 405W of power (I’m told possibly 410W but I’ll have to verify that once the system is up and running and I can connect to the Enphase microinverters). REC Alpha doesn’t have the same form factor as Solaria’s PowerXT 400, but it also seems like nobody else does. REC’s panel is 40 inches wide and 71.7 inches tall and weighing in around 45 lbs whereas Solaria’s is a little shorter but noticeably wider. Running the numbers the PowerXT 400 has 3,066.78 in2 while the 405AA has 2848 in2 making the REC panel have a slightly higher power density. While this by itself is a good thing, the potential trade-off is that Michigan fire code requires three feet of clearance around solar arrays for roof access making clustering panels sometimes more difficult on a complex roof like mine. Disclaimer: I am NOT an expert on this nor should you take my word for it or consider this reliable information. Do your due diligence and consult a solar engineer for your own installations and projects.
I said that REC Alpha took the lead out of the remaining choices and there are two reasons why: power output and annual power degradation. 405W at peak power output may only seem like a small lead over the Meyer Burger panels, however multiply that by 48 and you get a 480-960W difference. In the end I would need potentially two more panels to make up the loss in power generation. But where the REC panels really excel is power degradation over time.
When I was first informed that the Solaria panels were no longer available and then got presented with the alternatives I set about comparing everything to the Solaria panels. Until that moment I had never considered how much solar panels would degrade, though I was well aware that they did. What I found is that solar panels commonly degrade about two percent in the first year and then a little over one percent afterward, resulting in about 80% remaining efficiency after 25 years. The REC405AAs are rated to still be at 92% by this time.
By comparison, Solaria panels have a longer warranty period at 30 years but even after 25 years they will still degrade to about 87% according to their warranty spec sheet. Meyer Burger offers the same performance warranty as REC Alpha, but since the panel output is lower, REC remained in first place. As for Solarever USA they touted a “linear performance warranty” where their panels would degrade uniformly over time as compared to a claim of a steep drop after about 12 years with other brands. This doesn’t match up with any other company’s datasheets, however it’s still not impossible. But that being said, they still only claim the panels will be 83.1% efficient after 25 years, putting them in last place. While my choice of the REC Alpha panels will incur a short term increase in cost, long term this will pay off. To find out why, let’s do a little math.
My solar proposal recommended 42 400W panels to generate enough power to bring my total electricity consumption to a net of zero based on 2021’s power bill. While I don’t know whether panel degradation over time was factored in to the proposal, I’m assuming it isn’t for the sake of the calculation below. Since I’m installing 48 405W panels, let’s see if the addition of six panels is enough to account for the efficiency loss after 25 years.
- Total power of 42 panels at peak generation = 42 • 405W = 17.01kW
Total power of 48 panels at peak generation = 48 • 405W = 19.44kW
- Degradation after first year: 2%
Degradation in subsequent years: 0.25%
- Total efficiency loss after 25 years = 2% + (24 • 0.25%) = 8%
(this is in line with the claimed 92% efficiency after 25 years) - Total power generation after 25 years = 0.92 • 19.44kW = 17.88kW
I originally wanted the extra six panels mainly for aesthetic reasons since the pergola was designed to accommodate 24 panels and I didn’t want the house to have any large bare spots. Knowing now that the extra six not only accomplish this but give me extra power in the short term and are guaranteed to eclipse my established usage at 25 years (assuming no major changes), I think it’s safe to say that peace of mind has most definitely been obtained.
But everything above are just the top level selling points. In my next post we’ll dive a little deeper in the shadier side (pun intended) of things.