Best PV panels

[Greg Hilfman]

I'm getting ready to have a 7kW PV installed on a ground rack. I read very good things about the SunPower SPR-215 panels & gave a deposit to a local installer that uses these. Another pretty major PV dealer touts the RWE Schott ASE-300 as being the best. I'm spending a lot on this & want to make sure I get the best I can. Both products look fairly similar on paper, but I thought maybe some of you techies might have some insight.
TIA

[Rob Beckers]

Hi Greg,

Personally I don't really believe in a 'best' PV panel. They are just too similar. What I would look for is mono- or polycrystalline (and avoid thin-film), 25-year warranty (check how the warranty is defined so no tricks are played), good PTC vs. STC ratio, see http://www.gosolarcalifornia.org/equipment/pvmodule.php for PTC ratings (this gives a more real-world output number and will reflect better how much power you are going to actually get for your buck), UL1703 listing, and price-per-Watt. For 7 kW you should get a price break since that's quite a few panels.

Besides the above, you'll have to figure out (or have someone figure out) what voltage is going to work with the inverter you're planning to use, to make optimal use of it. Secondary criteria would be panel size, and Watt-per-square-foot, unless you're strapped for space.

There are many good brands. In fact, with the lengthy warranties now common there aren't really any bad ones left that I've heard off. What does vary quite a bit is real-world efficiency, reflected in their PTC rating, and it makes sense to look for panels that give good production for the money you're investing in them.

-Rob-

[Paul Bailey]

Everything Rob has stated holds true. I've always stated buy the best you can afford. The 7 Kw purchase gives you lots of leverage for getting a good price $$ regardless of who you buy from in whatever Brand lineup. . My thoughts were this 1) Stick with single crystal due to overall panel size and output in watts. 2) much better overall yearly output with single crystal. (because of low light efficiency improvement). 3) you are buying these for life.. Please give us more detailes on placement/mounting ,location( your latitude),connection to Grid that you are planning. Paul:)

[Renic Gunderson]

A small gap in performance between STC and PTC rating for panels can lead to a big gap in the return on the system over 30 years. I have run quite a few system comparisons, and I have found that the following brands seem to be the best, with some reservations:

sunpower
best solar cells on the market
more costly, but better return on investment
Sanyo
In the same class as sunpower, but no 25 years warranty
usually the most expensive panels, but again... better return

solarworld
High PTC to STC ratio
excellent quality tolerance (+/-3%)
needs more space than sunpower or sanyo

the next class of panels down my list would be evergreen, bp solar, sharp, and nearly every other brand out there are very similar.

I haven't looked at every panel on the market, but rob's advice holds true as a good way to judge quality difference.

In the end, you need to figure out your cost per killowatt-hour. If the price is right on a system, you may see a better return on investment from lower quality materials - most of the time, however, this isn't the case.

If you are really hurting for space, sunpower and sanyo have the highest wattage per square foot, but if space is not an issue look for the cheapest cost per killowatt-hour of power produced during a system's lifetime (or warranted lifetime).

[Andrej Marek]

Hello,

we are trying to solve out the similar problem. But for quite bigger plant of 1MW.
Do you have any ideas,hints or anything that could navigate us to the site where
we could see get info which panels have the best real performance according PTC?
Unfortunatelly we are not from US but Europe ( latitude 50)
If you had anything that could help us out, many thanks in advance :rolleyes:

[Rob Beckers]

Hi Andrej,

Welcome to GPT!
Seems the PTC vs. STC link I published earlier doesn't work any longer. I have updated it, and you can click it again (http://www.gosolarcalifornia.org/equipment/pvmodule.php) to get a list of PTC ratings for a great many modules. Things have improved over the last couple of years: Many reputable brands now have much narrower tolerances, such as +/-3%, and even -0%/+3%. That makes it much more likely that the modules live up to their production promise.

For 1MW in modules you should be able to negotiate a serious discount (and in fact buy at wholesale prices). I would suggest sticking with a well known brand name, and using the largest size module you can find in quantity (to save on installation cost and rack cost).

Keep us posted about your project!

-RoB-

[Dennis Kern]

I do quite a few installs here on long island and I use Sharp panels and find them to be great. There made nice and have a 25 year warranty. I just did a big one with 44 / 224 watt panels and 2 / 5000 watt Sunny boys. I dam near put the sun out when I turned it on :)

Peace along the way
Dennis the bus dweller N.Y.

[Rob Beckers]

I dam near put the sun out when I turned it on

:rofl: Hadn't heard that one yet! I'll it keep in mind when talking to potential customers...

-RoB-

[Ralph Day]

Yes, you really must consider your neighbours when doing RE work. Imagine if their garden, shrubbery or trees died because you sucked up all the sunlight!:eek:

Ralph

[Joe Blake]

Yes,

It could have dire consequences.

http://i82.photobucket.com/albums/j245/saxeharp/nghb02.jpg

jOE

[Ralph Day]

Those nieghbours obviously needed a taller fence. I wonder if you buy the shrub ''as is'' or if it requires years of loving attention and sculpting? Your garden Joe?

Ralph

[Joe Blake]

Those nieghbours obviously needed a taller fence. I wonder if you buy the shrub ''as is'' or if it requires years of loving attention and sculpting? Your garden Joe?

Ralph

Just a freak of nature, but the bush itself took some work.

:D:D

Joe

[Bill Marcus]

I have been selling Solar PV for 10 years, and have worked very closely with the Engineers, and have learned what makes a more efficient, better built Panel. Here is what most people believe.
Sanyo/SunPower always in a battle for Best, Sanyo triple layer Mono-Crystaline with one of the Layers being Thin Film, so it will produce with indirect sunlight. SunPower with the special made glass that directs more of the suns energy to the module.
Sanyo only module in the world that HEAT does not effect it's performance, so in hot climates it will product at a higher rate. SunPower has figured out how to get more power without making the module bigger.
Next best would probably be Mitsubishi, but they seem to be loosing the battle in the fact their modules are under 200 watts, Sharp is also very well built.

The Garbage out there that I would stay away from, Kyocera absolutely horrible, BP, Shell, most the stuff coming out of China. Just not cutting edge, or built as well, or as efficient, etc.

[Brian McGowan]

For what it's worth, I think lately I like the Sanyo HIT panels.
This thread was started in 2007. Did you get the install done Greg?

Brian

[Bill Marcus]

I think the Sanyo is #1 as well, but I have to Admit the SunPower is very close, you know if you look at SunPower Rating, they claim their Module is over 18% efficient, not cell, but the whole module. That is amazing.