Tesla Solar Inverter Notes
I did some more research today.
Tesla launched this product two years ago in Jan 2021, as indicated by an Electrek
article I found and a few other sources. Tesla's warranty document revision 1.0 is dated 7 Jan 2021 too. It looks like tesla.com has had this for a long time
Tesla Solar Inverter | Tesla.
So, why are we suddenly hearing about this again? It appears that for some reason Tesla recently decided to publish this whitepaper. Why they're doing it now instead of two years ago, I have no idea. The whitepaper is dated just "2022" on the document itself, but its URL address is "https://...blah blah blah.../Tesla-Solar-Inverter-Architecture-White-Paper-NA-EN-
12212022" indicating that it was published on 21 Dec 2022, which seems likely considering that this whitepaper hasn't been discovered by the online Tesla community until now.
[
Edit: Maybe published now because Tesla is now selling it to third-party installers]
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Tesla claims their inverter has reduced the all-in LCOE for home solar by 3-8% relative to competing systems. That isn't a massive difference overall, but if much of that cost improvement feeds into gross margin then it has been making a substantial difference for the profitability of Tesla Solar. The gross margins were thin to begin with, so a 5 or 6% boost is big and might double the profitability. If so, this has clearly been a materially contributing factor in Tesla's aggressively low prices for solar projects in the US and their price-match guarantee.
I don't have enough expertise in this area to evaluate how Tesla's inverter stacks up against other string inverters or how much their expertise and scale in power electronics really translates to cost and performance improvements as Tesla claims. It's one thing for Tesla to say that switching design architecture from having electronics on the roof under each panel to string inverters simplifies and saves money these days, but it's another to say that Tesla's string inverter solution is better than other string inverters.
Tesla claims the advantages over other string inverters are:
- Higher reliability
- 2x the standard number of MPPTs for high production on complex roofs
- Lower minimum input voltage per MPPT for enabling shorter strings of a few as two panels
- No neutral wire for simpler installation
- Seamless software integration with other Tesla Energy products
For any engineers who want to try tackling such a comparison, here is the official technical
spec sheet for the inverter and its integrated emergency shutdown device, dated 2 Feb 2022. We can take further discussion to the
engineering thread.