What are the best models of SunPower panels you can purchase for your home?

SunPower has been an industry leader in solar technologies since 1985 - and is involved in the research, development, manufacturing, and shipping of their technology worldwide.

Paying for quality is always worth it over the life of your solar system, and Solar Power stands behind their work.

Consistently producing the most efficient residential solar panels on the market, SunPower backs up their top-shelf offering with a strong product warranty and guaranteed 25-year power output back up.

How do I compare models of Sunpower solar panels to models from other manufacturers?

Our sister site SolarReviews has a solar panel comparison tool to show the pros and cons of the different residential solar panels brands sold in the US in 2018.

This tool allows you to compare two solar panels (either from the same or different manufacturers) side by side including the efficiency of each model, the wattage. Voc, Isc and the warranty information.

SunPower X-Series panels

The X-Series is SunPower’s top tier of panels, with an efficiency of 20.3% - 22.7%. Alongside SunPower’s standard 25-year product warranty, the X-Series has a power output warranty of 92% - even after 25 years! 

As well, the X-Series is rated to withstand high heat conditions. There are currently 16 available X-Series models.

Model	Module Efficiency
SPR-X21-470-COM	21.7%
SPR-X21-460-COM	21.3%
SPR-X20-445-COM	20.1%
SPR-X22-370	22.7%
SPR-X22-370-COM	22.7%
SPR-X22-360	22.7%
SPR-X22-360-COM	22.1%
SPR-X21-350-BLK	21.5%
SPR-X21-345	21.2%
SPR-X21-345-COM	21.2%
SPR-X21-335-BLK	21.0%
SPR-X21-335	21.0%
SPR-X21-335-COM	21.0%
SPR-X20-327-BLK	20.1%
SPR-X20-327	20.1%
SPR-X20-327-COM	20.1%

Note that models with "-COM" at the end of their names are for commercial use.

SunPower E-series panels

While not being as resistant to high-heat conditions as the X-Series, the E-Series are also top tier panels with efficiencies ranging from 18.1% - 20.4%. The E-Series panels still come with SunPower's strong warranty.

There are currently ten models available in the E-series.

Model	Module Efficiency
SPR-E20-327	20.4%
SPR-E20-327-COM	20.3%
SPR-E19-320-BLK	19.9%
SPR-E19-320	19.9%
SPR-E19-310-COM	19.3%
SPR-E19-315-BLK	19.7%
SPR-E18-300-BLK	18.4%
SPR-E18-300	18.4%
SPR-E20-435-COM	20.3%
SPR-E19-410-COM	19.1%

What is the best model of SunPower panel on the market?

Everyone has different needs and priorities when buying a solar system. However, the more efficient a solar panel is - typically the more it costs. My tip would be to buy the lowest wattage panel in a series. Why? Because most of these panels would have just narrowly missed out on being rated at a higher wattage.

So, for instance, in the E-Series, I would buy the SPR-E19-310-COM. In the X-Series, I would buy the SPR-X21-335. In both cases, these models are cheaper than the other solar panels in the series as most people tend to go for the more efficient higher wattage panels.

If you are looking to use the least roof space possible -- going for the highest efficiency X-Series panel would be the best choice. It will mean a higher upfront investment, but you'll be getting the maximum energy return per square foot and thus a better return on investment. If you have a larger roof and don't have as much to invest, an E-Series model will still give you a return and is backed by SunPower's warranty and decades of expertise.