Over the past three decades, solar panels have gotten much bigger - bigger in popularity and mainstream adoption, bigger in power output, and bigger in physical size.
Overall, this has been good news for off-gridders and renewable energy enthusiasts because it's meant that solar has been able to keep up with society's ever-increasing energy demands. But as the physical size of solar panels continues growing, it's beginning to present a few challenges that are important to be aware of.
Solar Panel Sizes
There are no hard and fast definitions around what makes a particular solar panel "small", "medium", "large", or "extra large." But over the years as modules' cell counts configurations have changed, we have seen some clear jumps up in terms of physical footprint.
From a freight shipping standpoint, anything over 8 linear feet typically incurs an extra fee (often called an over-dimension surcharge), so we use that as the threshold for "extra large" solar panels. And because we're talking about shipping here, keep in mind that panels slightly smaller than 8' will incur the over-dimension charge if the pallet they ship on (including the packing material used to protect it) measures over 8'.
As of this writing, Real Goods does not stock any panels this large, but that will change as extra large panels continue penetrating the market.
All products on the Real Goods website that are long enough in any one dimension to incur an over-dimension surcharge are marked with this 
image. The surcharge ranges from $90 - $125 depending on their exact length.
What to Know About Extra Large Solar Panels
In a nutshell:
- It's not possible install them or even move them around by yourself. Plan for extra help during your installation!
- It's not possible to lay them flat in a 7-foot truck bed with the tailgate closed.
- They're long enough to incur an over-dimension fee from most freight companies, meaning shipping them is more expensive, so make sure you order all your XL panels at once to combine them into a single shipment.
- They're also long enough that fork extensions are needed to move pallets of them with a forklift.
- Solar panels' additional weight and length compared to medium and large panels may require different racking configurations than you're accustomed to.
- Though the width and especially the length dimensions are increasing, their thickness is not increasing so far (and there's no reason we should expect them to), meaning the same solar panel clamps that have been on the market for years will continue to be compatible.
For more information about solar panel size over time and how we got here, read the full article about large solar panels increasing in size at the altE blog.
