Who to believe: SunPower vs REC REC Alpha REC400AA Pure Black

I need help better figuring out who to believe and what would be the best option for my solar installation. I live in Southern California. My 2022 yearly annual usage is: 6,416 kWh based on normal usage, not being actively conservative and not being overly indulgent with my A/C-Heating usage.

I have a 10-month newborn so I anticipate my electrical usage to increase over the next year and I will probably buy an electric vehicle in the next 2-3 years, driving 10,000 miles per year.

1. SunPower Quote

• 15 panels x425W M-Series with SunPower/Enphase IQ7 micro inverters = 6.375 kW system
• Est Yr 1 Production: 9,778 kWh
• $26,675. Installer says he’ll throw in a NEMA 14-50 plug for the same price (cost = $4.18/W based on system size)
• 25-year manufacturer warranty on performance/parts/labor
• 15-year warranty on penetration/labor

2a. REC Quote with REC Pro Trust Installer

• 15 panels x400W REC Alpha REC400AA Pure Black with IQ8M-72-2-US micro inverters = 6 kWh system
• Est Yr 1 Production: 7,949 kWh (shading on) / 9,057 Kwh (shading off)
• $19,550 with NEMA 14-60 plug installed or $19,050 without NEMA 14-50 plug installed, which is $500 difference (cost = $3.26/W based on system size)

2b. REC Quote same REC Pro Trust Installer

• 18 panels x400W REC Alpha REC400AA Pure Black with IQ8M-72-2-US micro inverters = 7.2kW system (however installer is not sure if he can truly fit 18 panels. He should be able to fit 16-17 instead)
• Est Yr 1 Production: 8,972 kWh
• $23,390 with NEMA 14-50 plug installed or $22,890 without NEMA 14-50 plug installed
• 25-year manufacturer warranty on performance/parts/labor because of REC Pro Trust Certification
• Installer claimed 25-year penetration warranty by their own company but I have to verify. He also said that penetration issues would arise in the first few years if anything….

Observations:

1. SunPower is more expensive but estimated Yr 1 production is way higher.
2. SunPower Est Yr 1 production is either really inflated or REC’s is underinflated.
3. SunPower M425 panels specs seem similar to REC400AA in terms of degradation and efficiency though SunPower are still a hint better (Efficiency of SunPower 22% vs REC 21.6% and SunPower 425W vs REC 400W)

I asked the REC installer why there was such a difference between his quote and SunPower’s Yr1 production estimation. He said his software takes into account shading in the production estimate. If he turns off “shading”, he says his 6kW system will produce 9,057 Kwh.

I have not yet asked SunPower rep the same question.

What would you pick…. or what tweak would you make to this installation?

My father-in-law got a SunPower system installed last August 2022 and he’s happy with it. He’s suggesting that I ask the SunPower rep to tweak the quote to 14 panels instead of 15 so it’s the same 6 Kw size and compare pricing then decide.

My initial goal was to maximize production upfront to avoid having to add panels down the road. Increasing size of the system would make force me fall into NEM 3.0 during upgrade VS being grandfathered into NEM 2.0 upfront.

If I was to measure cost based on 1 Yr production estimate;

• SunPower $2.73/Kwh
• RECa $2.46/Kwh (shading on) / $2.15 (shading off)
• RECb $2.61/Kwh (shading on) / He didn’t give me shading off estimate

Is SunPower worth the extra cost for the brand, “peace of mind” of the warranty and potential higher production/efficiency? What other questions should I ask myself or should I ask the installers?

Other considerations:

• My house has limited space on the roof. I don’t have too much space to add panels beyond 16-18 panels regardless of brand
• Both 15 panel designs have 10 panels on the west side (maxed out), 3 panels on the south side and 2 panels on the north side
• REC 18 panel design is basically making the south and north side 4 panels each (assuming it fits… and it may not)

Thank you!