Sunpower E20 327 AC vs 400W Maxeon 3

I am trying to install solar panels in my house and I decided to use sunpower after all my research, but after being quoted on the Series A 327W - AC i found the new panel came out of Series A 400W, i asked them to quote me on that and their quote is 19% higher on the price even thought the A 327 Ac need 46 panels and the A 400 Need 38 Panels
That does not make sense, I don’t know any company who developed better technology to reduce the numbers of panels and became much more expensive. That does not make sense at all. Please can somebody help me to understand If i am being taking for a ride by the contractor

Hi Alonso,

No, you’re not being taken for a ride. There is a good post on this here:

With solar, the pricing is per W. In both cases you getting a 15kW system, and it will take up similar amount of roof space (the 400W panels will take up slightly less space overall). The 400W panels are more expensive per watt.

I would suggest avoiding the 400W panels. You are paying a lot more, for a little more efficiency. Unless you are short in roof space, efficiency doesn’t really matter. You should also consider the LG Neon 2 panels, which are very good value.

What inverters are you considering with the 400W?

You may find this topic useful as well:

Also, check out our SunPower review:


Sunpower has their own version of micro-inverters, pre-installed by mfg, that are compatible voltage-wise with the E and X series. the 345wACPV and 360wACPV… the thing to keep in mind is that the micro is the same, and has a AC output limit of 320w. So, the 360ACPV might give you more net production if it is in a low angle roof mount, or in a location that does not have intense full sun; if installed in a place like New Mexico in a ground mount with 30 degree tilt, there will be a significant amount of clipping, and you would not get the full advantage of a higher output panel.

Same applies to LG - R versus LG - 2 with compatible Enphase iq7+. Yes the R is a higher output panel, but the iq7+ will clip above 290 watts AC. If you are installing on a low angle roof, or in a generally cloud/hazy place, the clipping may never be a problem, but in a high mountain desert it may be… Thus my recommendation that the higher output modules, either Sunpower 360, LG-R (moving to 370w), or top of the line Panasonics should probably be installed with SolarEdge string inverter and optimizers to avoid clipping loss if you want to maximize production.

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Interesting post dtbaker61. I was not aware of the iq7+ doing this above 290 watts. I had been looking at panel choices from LG, Panasonic and Sunpower (which was my fav) that were all above 290 watts though not as high as the 360+s. If this is the case yes I would agree it would eliminate the benefit of a higher output panel.

Take care,

You have to keep in mind that even the high output panels 360, 370 only attained those DC output values under perfect conditions. If you are doing a flat roof mount with a 10 degree tilt or off the Azimuth, or have hazy Skies where you live you may never see that Peak output.

Good production estimators take into account latitude, elevation, air quality, humidity, temperature, etcetera. And over time and experienced installer might adjust derate tables to be more accurate for local weather patterns, days of snow Etc

In many cases and installation with high output panels made clip only for an hour or so spring and fall when temperatures are cool and production is the highest. The amount that is clipped off the top of a daily production curve is usually less than the wider shoulders on the curve from a higher output panel so you do get the benefit compared to a lower output panel just not complete Peak output all the time with micro inverters under perfect conditions

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Thank you for your input