April 11, 2017
This past weekend, Tesla updated the “Solar Panels” section of its website to include photographs of the company’s sleek new modules. Tesla’s design replaces the sometimes-ugly aluminum racks of traditional solar installations with a sleek front-skirted system without visible racks, designed to look as good as the company’s cars.
That’s all Tesla has let on so far, except to the alternative transportation aficionados at Electrek, who got the lowdown about the panels’ power rating (325W), OEM (Panasonic) and manufacturing location (Tesla’s new Gigafactory in Buffalo, NY).
What else do we know about the new Tesla panels?
We know Tesla will begin manufacturing the panels later this summer, and we know they’ve been designed to “seamlessly integrate” with the company’s Powerwall battery storage modules.
It’s important to note that these are separate from Tesla’s upcoming solar roof tiles, which are more suited to new constructions. These panels are designed to be used like traditional silicon modules, installed over existing roof tiles.
We also know these panels look slick, using integrated front skirts and invisible mounting hardware developed by Zep Solar. The skirted look is something that’s not new to the industry, with offerings from ProSolar, among others.
And the new Tesla panels are probably mounted on something like Quick Mount PV’s Quick Rack product, although the Tesla solution admittedly looks a little better:
Durability and Lifespan of Tesla’s Panasonic Panels
One of Tesla’s claims about the new panels is that they “exceed industry standards for durability and lifespan.” So, what does that mean, exactly?
Well, the industry standard is a 5- or 10-year warranty for materials and workmanship and a 25-year power-production warranty. That means the panels shouldn’t fail because of mechanical defects in the first decade, and that they’ll be putting out at least 80% of their rated power by the 25th year on your roof.
But the top solar panel manufacturers have been moving toward longer time horizons for their warranties. Panasonic itself now provides a 15-year materials and workmanship warranty (pdf) for its newer panels, though its production warranty still guarantees at least 80% output after 25 years.
Efficiency of Tesla’s New Solar Panels
It’s tough to say just by looking at the pictures (which are probably high-quality 3-D renders anyway), but these panels look quite different from other Panasonic panels on the market. The 325W “HIT” panels currently offered by Panasonic measure 62.6 by 41.5 inches and are 19.4% efficient. But the panels on the Tesla image look more like 2×1 in aspect ratio, possible 72 by 36 inches. (It’s important to note that both those panel sizes take up about the same amount of roof space: 18 sq. ft.)
At that size, those 20 panels in the top image would take up 360 sq. ft. of roof space and produce about 20-30 kWh per day, depending on where you live. That compares favorably with the industry average of 280W per panel, which would produce between 14 and 23 kWh per day with the same amount of space.
One thing we don’t know is what effect the pretty front skirts will have on overall system efficiency. Blocking the space between the panels and the roof means reducing airflow, which can increase operating temperatures and reduce panel efficiency.
We reached out to Tesla, and they’ve promised to share data sheets about the new panels “in the next few weeks.” At that point, we’ll have a more in-depth look at what to expect from the new panels, skirts, and roof mounts. We’re also hoping to get more data about cost.
Tesla has a habit of releasing amazing products at premium prices, but we hope these panels will come in at a cost that will immediately appeal to the market, rather than target the wealthiest buyers. We’ll see.
Last modified: September 26, 2017