SunPower or LG?

[Old_Man]

Longi has long-been the bleeding edge of solar technology. Were I buying for my home or a class A RV, Longi is the only brand I'd buy. Better and less expensive. I no longer care about buying anything American . They've screwed me around long enough. Longi FOREVER!!!

Edit: Longi are also Tier 1.

[J.P.M.]

Sunpower has put their label on Sonny Boy inverters so that is what you may be getting with your quote. On the other hand LG announced some months ago that it was exiting the solar panel market. LG is offering $1 per Watt to its existing customers to swap out their failed panels which are producing only 70% of specifications after 2-3 years of use.

Sunpower never made an inverter. They've always rebadged other's products. Sunnyboy and Power One were two back in the day.

As for their panels, and seeing as how this thread is all over the place, they were once sort of the quality standard, part of which was true and another part of which was B.S. marketing.
I bought and knowingly paid a premium for a S.P. system to run experiments and comparisons with neighbor's equipment as I've documented and written about on this forum to see if their marketing hype had any truth to it with respect to their "most efficient" claims.
After 6 or 7 years of careful comparisons, I believe that claim to be B.S. largely used to dupe the solar ignorant (which is mostly everyone).
My panels however, have operated flawlessly for about 9.5 years and I believe have produced output somewhat better than their data sheets claim as well as slightly less performance degradation than the spec sheets claim.

But I'm just as sure that, after pretty careful comparison with data taken from about a dozen cooperating neighbors that S.P's overall performance is no more superior in terms of annual specific output (kWh/installed STC kW) than other quality panels.
At the time (~ 10-12 years ago) S.P. were able to garner what was about a 20% smaller S.P. footprint for ~ 25% more $$s up front based on the bogus area efficiency game. All they had was an area efficiency. Most of that B.S. is still true, except I'm no longer sure their quality is as good as it was.
Result then and I believe still true: All equally sized (from STC wattage standpoint) systems using reasonable quality equipment that's professionally installed, operating in the same location and orientation will (within a small tolerance of a % or so) produce about the same annual output.

I do know however that back in the day I also cleaned up on S.P. stock whose hefty premium was supported in large measure by their "most efficient" advertising hype that supported the (inflated) premium price.

[Calsun]

Solar panels only vary in their use of bypass diodes to minimize output power loss with partial shading of a panel. It is the efficiency of the inverter and its reliability that should be the focus. My inverter failed in October of 2022 and as of February 2023 SunPower continues to blow me off. Having an inverter under warranty is of no value if the manufacturer/distributor decides not to honor the warranty.

I replace the SunPower (Sunny Boy) inverter with one manufactured by Solis that appears to be the best one can buy for residential applications. Their "5G" models will also suport a battery bank backup system with charging provided by the solar panels. Wifi is easy and inexpensive to add to any of the Solis units through an externally accessed port (same one used to apply firmware updates). I can check the new Solis inverter at its display or over the internet with a computer or using a smartphone.

[GDunk]

The inverter being quoted is Enphase IQ7HS Microinverter with SP panels.