SunPower Corporation - Inverter Reviews

About SunPower Corporation

SunPower was a pioneer of solar panel manufacturing - but it also dabbled in inverters as well.

Company Info

Sunpower Corporation founder Richard Swanson began pondering the use of solar power in the 1970's during the oil crisis at the time. At that point, solar PV was pretty much confined to space applications. In 1985, SunPower was officially incorporated after Dr. Swanson was awarded government grants and financial support from two venture capital firms.

Sunpower Corporation then started supplying solar products to residential, commercial and utility-scale users, all developed with proprietary technologies. In 2019, SunPower announced it would spin off much of its solar panel manufacturing into a new company – Maxeon Solar Technologies.

SunPower Corporation in the USA filed for bankruptcy protection in 2024.

SunPower Inverters

While SunPower was primarily focused on solar panels, they also offered string inverters - and through a company it wound up acquiring, microinverters that were embedded on the back of some of their panels.

SolarBridge Microinverters

SunPower got into the microinverter sector through its acquisition of SolarBridge Technologies in 2014. But in 2019, Enphase Energy bought this part of SunPower’s business for USD $25 million in cash and 7.5 million shares of Enphase common stock. Enphase microinverters continued to be used when SunPower spun off solar panel manufacturing to a new company, Maxeon Solar Technologies. These, and some other Maxeon panels, still carry SunPower branding.

SunPower M Series String Inverters

SunPower also offered several string inverters - the SPR 3000MTL-1 (3kW), the SPR 4000MTL-1 (4kW) and the SPR 5000MTL-1 (5kW) among them. Weighing in at around 40 kilograms, these were hefty transformer-based beasts.

How long these were available for isn't clear - a very old datasheet we sighted had a date of 2007.

Warranty Information

SunPower panels with SolarBridge microinverters had a 25 year warranty. The 3000MTL-1, SPR-4000MTL-1 and SPR-5000MTL-1 string inverters were accompanied by a 10 year warranty.

It's unlikely there are any SunPower string inverters still installed in any quantity, let alone covered under warranty. But some original SunPower AC solar modules would (and should) still be. If you have an issue with one of the company's AC solar panels, first talk to your installer - and if they aren't around any more, contact Maxeon (they committed to honouring SunPower warranties).