Mono or Poly panel

**jadi** · March 29th, 2010, 14:57 PDT

Hi, I want to have a 6.5kW GT system install at my house in Freehold, NJ. Two installer came to measure my roof last week and estimate. Both same price, $6/watt installed.
One installer offer to use Suntech 200W polycrystalline panel with SMA inverter. Another uses Suntech 175W monocrystalline panel with Xantrac inverter.
When I ask about the panels, they both says their panel is more suitable for my application.
Can anyone tell me if it makes any difference. Is one (panel) better then the other? Is $6/Watt reasonable. What is the going rate in NJ. What should I really be looking for.

Thankyou
jadi

**mike95490** · March 29th, 2010, 15:29 PDT

I like the Xantrex inverter - no fan, and easy connection to serial cable / USB to any windoze computer. If you can't monitor monthly trends, you have no way of knowing if anything is wrong.
Compare warranties and service, What happens in 14 months, when you see a brown spot appear on a panel, who comes out and replaces it, and who charges you to replace it. 2 year warranty parts & labor would be good, 1 year minimum.

What about the energy harvest, any difference between them ? any shade issues on your roof? All on the same plane, facing the same direction, or 16 east, 12 west ?

**jadi** · March 29th, 2010, 19:05 PDT

Mike,
Zero shade. 70%NE, 30%NW. I just got off the phone with one of the installer. He said if I am not comfortable with Suntech panel, they also have ET175 panel (same price as Suntech) and Sunpower panel ($1/watt more). All 10yrs parts 3yrs labor warranty. Monitoring system (optional). Both company are reputable in our area.
What is the determination factor for a new solar system.

jadi

**niel** · March 29th, 2010, 21:01 PDT

jadi,
i do hope that you meant se and sw if you're in the northern hemisphere. as to the pvs it has to do with the installer's personal preferences as well as minor compatibility differences with different inverters. you could approach them and ask what they think of the other proposed system from the competition. it doesn't hurt to let them know you won't just fall down and buy from one without checking others. it might stir some competition too.

**jadi** · March 29th, 2010, 21:48 PDT

Oops, You are right. I mean 135SE & 225SW.
So, I guess is $/watts with the Suntech selection situation ( Mono or Poly ).
How about the Sunpower. Is it worth paying $1/watt extra ?

**niel** · March 30th, 2010, 2:29 PDT

some would say mono and some may say poly. not big differences as watts is watts. this is true of the sunpower as well, but they have a higher efficiency. no that doesn't mean you get more watts/$, but it means you get more watts for a given area. that allows you to squeak a few more watts out if you are cramped for space, but is it worth another $1/w? go by other factors like the cost or the warranty or similar things.

**jadi** · April 9th, 2010, 6:59 PDT

Sign yesterday. Suntech 175 mono all black, l think it looks nicer than poly on roof. They say its gonna take 6-8 weeks before they can install. Once installation start it will 3 days.
I'm getting my roof replace at meantime. Needs to move them vent pipes too.
Thanks guys.

jadi