Suntech 280 watt panels and design ideas

[NABCEP Russ]

IMHO if you really want to get the most wattage per square foot of space look at the sunpower modules. If you have shading you will have to get permission from Sunpower to use microinverters and they are pricey. I agree with the others that for the most part module output is a function of size. The Sunpower modules have a slightly higher conversion rate than the others.

Sanyo is another option for high power density. They have some interesting technology. They are also compatible with the Enphase M210 micro inverter so you're not limited to 190w.

[russ]

That particular document has good explanations of various terms as well.

Look at the design tool I provided a link for earlier in this thread. It allows you to select from various manufacturers panels and then compare them side by side.

Russ

[solarrules]

I still encourage you to do your own research and reading. Here's a good place to start:

http://homepower.com/view/?file=HP134_pg50_Sanchez

A pretty good table in there to do comparisons.

[Naptown]

IMHO if you really want to get the most wattage per square foot of space look at the sunpower modules. If you have shading you will have to get permission from Sunpower to use microinverters and they are pricey. I agree with the others that for the most part module output is a function of size. The Sunpower modules have a slightly higher conversion rate than the others.

[Mike90250]

......
Is there a manufacturer of inverters that everyone should stay away from ALWAYS? (I heard about Schneider recalling the Xantrex grid-tied inverters last month.)....

I think I would still lean toward Schneider / Xantrex. Passive cooling via a monster heatsink. They are being up front about replacements, and it's a counterfit part that's caused the problem, not a design issue.

Also to consider, is monitoring options/features. See what's important to you, and how much it costs to get the data. Xanterex GT series have a serial port with data sitting there ready to go..

[greg kindy leed ap]

Well, I'll leave the NABCEP issue behind.

That's interesting what you say about enclosure. I get that.

Thanks!

[NABCEP Russ]

Awesome thread.

So, yeah, buyer beware about who makes The Best Panel on Planet Earth. It's system that matters in the end; sizing it to get the tier-shaving and load-shaping that's wanted by the building owner/user. "Best Panel" is advertising. It's catchy. But not useful in and of itself.

That said, so then in terms of strings are we talking NABCEP standards? In terms of inverters - assuming the inverters are sized right - are we talking superior brand?

Is there a manufacturer of inverters that everyone should stay away from ALWAYS? (I heard about Schneider recalling the Xantrex grid-tied inverters last month.)

What does everyone think of Fronius?

Not sure what you mean by NABCEP standards. Usually strings are determined by inverter input ranges and of course the NEC.

I like PVPowered, SMA, & Enphase inverters. Fronius is ok, but not my favorite. I think they're harder to wire than the above brands. I just don't like the feel of the cabinet. Purely opinion. I also don't feel like their enclosure is as robust as SMA & PVPowered.

I've stayed away from Xantrex for the last couple years because of recall issues. The current recall isn't the only trouble I've heard of them having. I figure with SMA and PVPowered, I don't really have a reason to bother with Xantrex.

[greg kindy leed ap]

Awesome thread.

So, yeah, buyer beware about who makes The Best Panel on Planet Earth. It's system that matters in the end; sizing it to get the tier-shaving and load-shaping that's wanted by the building owner/user. "Best Panel" is advertising. It's catchy. But not useful in and of itself.

That said, so then in terms of strings are we talking NABCEP standards? In terms of inverters - assuming the inverters are sized right - are we talking superior brand?

Is there a manufacturer of inverters that everyone should stay away from ALWAYS? (I heard about Schneider recalling the Xantrex grid-tied inverters last month.)

What does everyone think of Fronius?

[Sunking]

There's nothing wrong with 180w modules.

Agree the panel wattage is a function of the best series/parallel configuration of the inverter used.

[russ]

NABCEP Russ made an important point that I would like highlight. It is a common misconception that a 280 watt panel is somehow better than a 185 watt panel.

The higher watt panel is not better but is physically bigger.

Similar with efficiency - unless you have space limitations on your available area it makes little difference whether a panel is 13%, 14% or 15% efficient.

What you do care about is cost per watt.

Russ

[DrLeePhD]

The dimensions of the Suntech 280, as they appear on the product spec sheet are 77 inches by 39.1 inches. Assuming you'll put the 12 panels in two rows of six, and allowing for space in between the panels and at the edges, you'll need an available roof space of roughly 21 feet by 14 feet. As far as pricing, my company offers them for cheaper than what you were quoted, although that's not including shipping and we only sell Suntech panels in pallets of 26. I'd put the link up here, but I don't want to violate any forum rules. I guess just know it's possible to get em cheaper.

[NABCEP Russ]

GTOjohn,

I'm am amateur at this and learned much of my knowledge from reading, reading, reading - only about an estimated 15% of my knowledge currently comes from real world experience including the Harbor Freight kit.

That said..... I couldn't agree with you more that 185 Watts is too small today. I had contractors bid the same to me -- They INSISTED on 180 Watts, and I finally told them to go pound sand.

Almost seems as if they have bought panels 10 months ago and now are trying to sell them to us. They push hard. Tell them to pound sand.

The sweet spot (on pricing) seems anywhere from 200 to 240 Watts depending on brand.

Sorry I didn't answer your actual question, but I wanted to let you know that I support your thought process. Do your own homework and know exactly what you're buying.

There's nothing wrong with 180w modules. It's a very common form factor. The only difference between that and a 230 is the number of cells. A 230 is simply physically larger than a 230. In some cases certain roof dimensions may be better suited to a smaller module. Its not a case of being outdated, but a question of format. At some point Schott offered a 400 watt panel. It only achieved that wattage by being huge.

I once installed a system that could fit more wattage if we used 180s just because of the layout of the roof vents.

[solarrules]

185 seems low to me

GTOjohn,

I'm am amateur at this and learned much of my knowledge from reading, reading, reading - only about an estimated 15% of my knowledge currently comes from real world experience including the Harbor Freight kit.

That said..... I couldn't agree with you more that 185 Watts is too small today. I had contractors bid the same to me -- They INSISTED on 180 Watts, and I finally told them to go pound sand.

Almost seems as if they have bought panels 10 months ago and now are trying to sell them to us. They push hard. Tell them to pound sand.

The sweet spot (on pricing) seems anywhere from 200 to 240 Watts depending on brand.

Sorry I didn't answer your actual question, but I wanted to let you know that I support your thought process. Do your own homework and know exactly what you're buying.

[So solar]

Nice job

[NABCEP Russ]

That can be said about alot of modules. The difference is about 50 watts. Why use enphase on all your installs when you max out at 200 watts. Seems odd. I believe enphase to be good for shady areas. That's the only reason. Your driving the cost up to the green customers, when its not necessary. Why limit yourself to 200 watts, extra eqipment and loads more wires. Especially with enphase lack of a track record?

The simpler engineering process, simple inventory, and faster install time saves me enough money that I can offer enphase for the same price as a central inverter. The only downside to me is the track record, but they've done a good enough job convincing me of the quality of their product.

Another benefit of enphase is module level MPPT. This way each module is performing at it's best within the power tolerance range.

I just installed a 23kw residential system with enphase for the same price another company quoted for a central inverter. It's all about efficiency within the installation company and we excel at efficiency.

Also regarding using a 230w module on a 200w inverter, with temperature losses and lack of true 1000w/m^2 irradiance, modules rarely peak over 200w the amount of clipping is insignificant and will only lessen with time.