Sunpower 327 with their Equinox microinverters vs LG Neon 2 305 with Solar Edge

[dlmb1004]

I keep thinking I'm ready to choose between two quotes, but then your feedback leads me to ask more questions and refine my quotes. After your previous feedback, I'm looking at more efficient panels and again, I need your advice!

Here are my two quotes:

LG Neon 2 (36 305w panels with Solar Edge)

System Size: 10.98 kw (36 panels)	New proposal
Initial Cost	$34,585	$3.15
Earth Day Discount	$1,729
Utility Rebate	$7,027
City Rebate	$5,000
Federal Tax Credit	$7,749
Final Cost	$13,080	$1.19

SunPower Equinox (28 227w panels)

System Size: 9.2 kW 28 Panels
Initial Cost	$35,251	$3.83
SunPower Promotion	$3,000*
Utility Rebate	$5,325	$5325.00
City Rebate	$5,000
Federal Tax Credit	$8,978
Final Cost	$12,948	$1.41

* This is assuming I can find someone who works for Sun Power. If not, the discount is $1,500.

What do you guys think here? This is a HUGE amount for me to pay for solar panels.

Also, I live in North Texas, where it is HOT. I will not be eligible for the city rebate next year, so I need to do what I can now. The panels will be on a western and eastern facing slopes. Here is the PVWatts data:

			LG	SunPower (+8%)
January	276.5	211.9	488.4	527.4502
February	377.6	270.9	648.6	700.4372
March	556.4	407.5	964.0	1041.072
April	519.2	392.4	911.7	984.5992
May	513.7	395.1	908.8	981.4823
June	700.3	522.1	1222.4	1320.171
July	787.5	563.3	1350.8	1458.823
August	710.8	529.4	1240.2	1339.422
September	587.3	467.4	1054.7	1139.073
October	404.1	309.1	713.3	770.3485
November	280.1	220.0	500.0	540.0215
December	286.5	224.5	511.0	551.8522
11354.75			10513.9	11354.7521

This covers about 95% of my electric usage, but unfortunately, isn't enough to cover an electric car I plan to buy in the next year or two.

[brewbeer]

Shouldn't the LG system (10.98) generate about 20% more kWh than the Sunpower system (9.16)?

[sensij]

Shouldn't the LG system (10.98) generate about 20% more kWh than the Sunpower system (9.16)?

Yes... it isn't clear what was done differently between the two runs in PVWatts, but they should have been modeled under the same assumptions. There is no way a system 20% smaller will outperform the larger system by 8%.

[cebury]

Yes... it isn't clear what was done differently between the two runs in PVWatts, but they should have been modeled under the same assumptions. There is no way a system 20% smaller will outperform the larger system by 8%.

Perhaps he believed the SP sales pitch about 8% more efficient because the SP totals are 1.08x more then column 4.

[dlmb1004]

Thank you. I was thinking that I just didn't understand this. The SunPower guy said you didn't need as large of a system using SunPower as you do LG because SunPower is are more efficient. He actually ran the PVWatt's and sent me that spreadsheet. I wanted to see the expected energy generation with x panels on the west and y panels on the east, as it's arranged on the quote. Sure enough, it didn't produce nearly as much power as the ideal southern facing scenario that everyone typically quotes.

[ButchDeal]

So your charts above do not state that one is east/west and the other is south only.
Is the lg set up with the same amount facing south?

[dlmb1004]

I think I'm doing a horrible job of explaining this. The SunPower quote assumes south facing panels. However, mine have to best west/east, so the Sun Power sales guy put my roof configuration into PVWatts (first running the panes on the west then the east and then consolidating the numbers into one spreadsheet). So the estimated production went from 14K to 11K because the panes will not be facing south.

[ButchDeal]

I am still not following you
It doesn't sound like it was modeled correctly.

Are you saying that south is shadowed?
If you have the same size ( in watts) in the same configuration regardless of brand name, they will produce nearly the same.

[inetdog]

You do not need as physically large an array with SunPower. But the efficiency difference in watt-hours produced per nominal watt of panel is not very great.

[huge]

For the same price, I would almost definitely go with the larger system, as long as you properly place them. Those LG panels are not far from the quality of the Sunpower ones. Think about it, even if a few of the LG panels or optimizers go bad, you still produce more electricity than the other system. Most installers will try to trick you one way or another, so don't take their word for it. Run the numbers yourself

[NYHeel]

As others have said, your pvwatts spreadsheet has to be wrong, or at least not a consistent comparison. The LG system has to outperform the sun power one as long as the panels are similarly placed. Run the pvwatts numbers yourself.

[Ian S]

I agree with others: the calculation is faulty. A 9.2 kW Sunpower array is going to produce significantly less electricity than a 10.98 kW LG array set up the same way at the same location. The Sunpower setup may degrade slightly less over the decades but that will never make up for the initial power difference. The "efficiency" advantage of the Sunpower panels is an areal efficiency meaning higher power production per sq. ft. of panel. Unless you are severely limited in roof space, it is not a significant factor in selecting a panel. To put it another way, a 10 kW Sunpower system will produce - at least initially - virtually the same as a 10 kW LG system but that LG system will take up more space.

[easye]

I ran the PV watts for my address just east of Dallas. Complete array face west LG - 15,684 KWh AC, East LG 15,505, East and West LG 15,595, South LG 17,707.
As for the SunPower. I ran the numbers and assumed they would outproduce the LGs bu 8% over name plate. West SP 14,319, East SP 14,160, East West SP 14,14,235, South 16,180
If only using name plate - SP west - 13,142, SP East 12,994, SP East West 13,069, SP South - 14,860
My guess is the truth is somewhere in the middle. I know for a fact that my LGs outperform my Solar World panels by about 6% name plate to name plate. I'm pretty sure Sun Power is talking about panels like that and not Neon 2s. I'd say at best the SP might beat the Neons by 4% but probably closer to 2%.
With that in mind, LG East West combo would be 15,595 and Sun Power would likely produce 13,303.
Choice seems easy to me. LG all the way and you are going to love the Solar Edge system. You get that Tesla later it's really easy to add panels to a Solar Edge system. I added two panels and myself and my net cost was $1.28 a watt. I live in North Texas too, and I figure with our rate system and the credits I can get with Oncor as my provider why not go a bit over 100% and bank while I can.

[dlmb1004]

Thank you! So helpful.

[easye]

For what it's worth, my 8.8 system in 2015 produced 12,500 kWh AC with PV Watts suggesting that it should do 14,179. Keep in mind last year was the rainiest on record. So far this year through may I'm already 1200 kWh AC above where I was last year, so I'd say PVwatts is going to be pretty close as I will likely be well over 14200 this year.

[dlmb1004]

Thanks everyone! I think I will just go with the LG and be quite happy!