Quote/Panel/Negotiation advice

[Jafoy]

Hello

I'm about ready to pull the trigger on a solar system, and I wanted to see if anyone had any recommendations for the quotes I'm looking at.

#1 - Company A - $3.09
System Size - 12.32kW - expected offset 65%
44 Trina 280W All Black panels
44 SolarEdge Optimizers
1 SolarEdge Inverter SE10000A-US
Total - $38,055.56 (Includes financing costs)

#2 - Company A - $3.28 ppw
System Size - 13.20kW - expected offset 70%
44 Suniva 300W All Black panels
44 SolarEdge Optimizers
1 SolarEdge Inverter SE10000A-US
Total - $43,296 (Includes financing costs)

#3 - Company B - $2.98 ppw
System Size - 15.95kW - expected offset 82%
55 Hanwha 290W All Black panels
55 SolarEdge Optimizers
1 SolarEdge Inverter SE10000A-US
Total - $47,497.07 (Cash cost - does NOT include financing costs)

Some background -

We will be financing (I know that's a whole other discussion, but not the focus of the question), likely via Dividend. We're in SC, so get an extra 25% credit via state incentives. I'm limited in the amount of roof space available, in that we're trying to keep from putting panels on the street-facing side of the house.

There are some large pines behind the house (not in our yard) that do provide some early morning shading. The sales person from Co. A said that to make sure he wasn't over promising he'd drop the offset from 70% to 60% on quote #2 (I assume a similar drop for the others), though I really don't remember seeing much shade on the roof during the months that we actually go outside, so hopefully the shade isn't as bad as that. I've tried to find historical aerial images that would show various seasons, but found few, and no shade at the times of year/day that they were taken. If anyone knows of a better resource for this I'd be interested.

I'm leaning towards #2 due to the larger offset, and not dramatic price difference (only half of which I'm on the hook for). It's still more than I'd like to pay however.

The third, while the cheapest per watt, concerns me for several reasons. This company came back to me out of the blue ~2 months after last contact, with a new quote. They're another local company with good reviews, but were quoting me prices in the $3.60 or so range, and I told them that the competitors were coming in at around the $3 mark (#1 was initially a $2.95 quote when they had different 290W canadian solar panels available at similar costs). I don't know yet how much the price in option #3 will go up due to financing costs. Additionally, the extra 11 panels are on a N/NE roof face that we'd been avoiding using because it didn't seem terribly efficient, and some of the other panels are arranged in a manner that I don't think is realistic (too close to the chimney, which IS shaded year-round, etc). PVWatts had been down, but I just checked again and it's up, and their numbers as listed actually do add up, which surprised me a tad. The size of the inverter also seems a bit off here, though. I guess the theory is that the system would never really be operating at 100% efficiency? Still, the inverter seems undersized, am I crazy here (the spec sheet shows a max DC wattage of 13.5k)?

First question - are all of those panels pretty much of the same quality? Anything worth mentioning there? I'm operating on the assumption that those brands are basically interchangeable quality-wise, so please correct me if I'm wrong.

I'm inclined to go with Company A since I've been working with them much more closely over the intervening months, and I think their solution is a bit more realistic. However, I don't want to discount the lower cost completely. I haven't had time to ask yet, but does anyone know what kind of markup I should expect going with a dividend financed system vs. cash? I'm also a terrible negotiator, would it be imprudent to try to leverage the lower price from company B to get a lower price from company A? Or just flat out ask them if there's any wiggle room there to make their larger system a bit more attractive?

Thanks for any advice, this forum has been invaluable as a learning tool over the past few months.

[ButchDeal]

There seems to be little reason why these three bids would use the SE10000 over the SE11400. The cost difference is almost nonexistent.

all the quotes are with BoB ( black on black) modules which increases costs a bit. Black on white are cheaper and have higher performance

[Jafoy]

Thanks for the input.

all the quotes are with BoB ( black on black) modules which increases costs a bit. Black on white are cheaper and have higher performance

Just to make sure I understand - the black-on-white have higher performance simply because they don't overheat as much, correct?

I was looking for different temperature coefficients on the datasheets and was confused when they were the same (aluminum vs black), but it would make sense if they were rated the same and the black just got hotter. Which is in issue where I live.

[inetdog]

Thanks for the input.



Just to make sure I understand - the black-on-white have higher performance simply because they don't overheat as much, correct?

I was looking for different temperature coefficients on the datasheets and was confused when they were the same (aluminum vs black), but it would make sense if they were rated the same and the black just got hotter. Which is in issue where I live.

Absolutely right.

[Jafoy]

There seems to be little reason why these three bids would use the SE10000 over the SE11400. The cost difference is almost nonexistent.

Another question - what is the benefit of going with the larger inverter if the capacity isn't needed (and other features look the same)? it would make room for further expansion, but will it also extend the life of the inverter?

I thought that I'd also read at some point that you should try to max out an inverter to a degree, but sizing up would seem to counter that, so I'm guessing I'm remembering wrong?

[ButchDeal]

#2 & #3 are going to clip with a 10kw inverter.
wanting to max out is old school and not appropriate for solaredge which has higher efficiency ( slightly ) below full load instead of at full load.

[Jafoy]

Got it, thanks.