Comparing panel brands suniva and canadian solar

[paladin732]

Hi!

I am somewhat new to this and have been trying to do my homework. The biggest thing that I can not find is the differences between panels.

I have two installers I am debating between, both are matching each other's prices ~$14,500 for a 6.5Kw system with microinverters on a spanish tile roof in Northern California.

They are both offering 10 year gaurentees on the roof (one gave me a signed warranty from the owner, and the other its normal policy).
They are both offering the price through clean power finance. Every company I have spoken to that uses clean power finance, says the odds are that they either won't want much, or can be talked into just leaving the system on the roof for free at the end of the lease, because it will be worth so little money (and it won't be worth their time to remove it). What are the odds of this being correct do you think? They are sales people, so I have to take what they say with a grain of sale.

The biggest difference is one is using Canadian Solar 250w all black panels(working on getting the model number), and the other is using Suniva OPT260-60-4-1B0.


So my questions are:

1. Did I get a good price (I did a lot of haggling and had companies compete off each other)?
2. Is there any real difference between the canadian solar and the suniva? Is there any reason one is better then the other? (The Suniva is 25 panels, Canadian Solar is 26 panels)
3. One is gaurenteeing 9900kwh (canadian solar guy) and the other is 9151kwh(suniva). How much are these guys most likely lowballing it? Is there any reason they should be giving me different numbers?

[Naptown]

That is almost a megawatt difference in the performance guarantee. A huge difference.
I would make them show you the solmetric eye or pathfinder or even the PVwatts output numbers.
Along with that the derate factor each was using to determine the output.
Canadian Solar is a company incorporated in Canada and manufactures in China. There have been reported instances of defects (snail trails) that could degrade the performance of the modules. (I have not seen these yet although have installed CS modules)
Suniva is a US company that manufacturers it's cells in Georgia and assembles elsewhere although there are US made modules available.
Compare the warranty of each manufacturer. And what it takes to make a warranty claim. Also take a look at the fiscal health of each company and make your decision from there.

[paladin732]

That is almost a megawatt difference in the performance guarantee. A huge difference.
I would make them show you the solmetric eye or pathfinder or even the PVwatts output numbers.
Along with that the derate factor each was using to determine the output.
Canadian Solar is a company incorporated in Canada and manufactures in China. There have been reported instances of defects (snail trails) that could degrade the performance of the modules. (I have not seen these yet although have installed CS modules)
Suniva is a US company that manufacturers it's cells in Georgia and assembles elsewhere although there are US made modules available.
Compare the warranty of each manufacturer. And what it takes to make a warranty claim. Also take a look at the fiscal health of each company and make your decision from there.

Yea, the thing is that the Clean Power Finance agreement says that if the wattage doesn't work after the first year, they can re-baseline it. So I am not sure if I trust the numbers.

The 9900Kwh has been on my roof, the other has not.

[Naptown]

I can run some numbers for you via a pathfinder report.
However I need to know the following
zip code
azimuth (true direction the panels will be facing)
Tilt (pitch of roof)
If any shading between 8Am and 6PM at any time of the year.
Inverter model and quantity
Module model numbers.
If there is any shading my numbers may be off as I cannot see the actual site. If no shading I can get very close.

[paladin732]

Thanks!
Zip is 95123
This is what the quote from the 9900kwh people say

System Size DC 6.500 kw
Shading (% Sun) 98.00%, 95.00%
Direction 170°, 260°
Slope 10°, 20°

Is that the information you need? (I don't think there is really any shading over my house, I'm in the middle of a community with no trees, only shading would come from neighbors houses, which depending on where they put the panels may block some light at some points)I can see if any of my other quotes have more information on them?

Also, is the pricing good?

[Naptown]

Thanks!
Zip is 95123
This is what the quote from the 9900kwh people say

System Size DC 6.500 kw
Shading (% Sun) 98.00%, 95.00%
Direction 170°, 260°
Slope 10°, 20°

Is that the information you need? (I don't think there is really any shading over my house, I'm in the middle of a community with no trees, only shading would come from neighbors houses, which depending on where they put the panels may block some light at some points)I can see if any of my other quotes have more information on them?

Also, is the pricing good?

Slow down coyboy
You have 2 directions and 2 slopes how many modules on each one and which is which

[russ]

Shading can also be from chimneys or stand pipes - electrical service or power poles.

[paladin732]

Slow down coyboy
You have 2 directions and 2 slopes how many modules on each one and which is which

They are telling me this: "We can fit 8 panels on your south roof and 18 on your west roof"

We are doing enphase microinvertors and either 26 canadian solar 250w or 25 suniva 260w

[paladin732]

Shading can also be from chimneys or stand pipes - electrical service or power poles.

There is no chimney and no power poles I think the only main shading may be on the lower roof portions from other homes, but I don't think they were planning on using those.

[SoCalsolar]

Use this calculator

Lets not reinvent the wheel here. This how your rebate is calculated use this to determine production. You will need to run two calcs one for East and one for West add them together and thats what you get. Choose the panel and inverter etc..

http://www.csi-epbb.com/default.aspx

It's very conservative but should be so equally and here is an article about snail trails in Canadian Solar panels there are others.

http://www.wrecked.net/Solar/Photon-Mag%202012-01%20SnailTrails.pdf

At the end of the lease I don't believe you are getting to keep them. I'll have to read the PPA terms for CPF again but I don't believe its an option but it does make a nice story.