Most Efficient Solar Panels
| Published in Efficiency | 13 Comments
Two great questions many people ask about solar panels are: “Which panels have the highest efficiency?” and, “Which solar PV panels are the best?”
This solar power panel comparison chart (from SRoeCo’s sortable, searchable Solar Panel Comparison Table) compares the output per square foot surface area of most 200 W model solar panels. All of the modules on this chart are label rated at 200 Watts, which means in strict laboratory conditions, they produce the same output. However, I have compared them based on their PTC ratings which is the rating given under realistic test conditions. Sanyo, SunPower, Schuco, Kyocera, Suntech, GE, Evergreen, Canadian Solar, and Sharp are common solar panel manufacturers used by installers in the US.
(click image to enlarge)
Of the highest output panels, both Sanyo and SunPower panels have the highest efficiency per surface area in real world conditions. Given a limited roof area with which to install solar panels, these panels are the best choice to produce the most electric output per square foot. However, this doesn’t mean that these panels will always be the best choice.
The chart below shows 30 of the most common and efficient solar power panels on the market and listed on the State of California’s “List of Eligible SB1 Guidelines Compliant Photovoltaic Modules” as of July 1, 2009. The PTC/Sqft is basically how many watts per square foot that panel will produce. (click on image to enlarge)
So, if I know the most efficient solar panels, then I know which solar panels are the best, right? Well, if efficiency is all you care about, then yes. But efficiency may not be the most important factor. I would argue that the two most important factors in choosing the best solar panels are 1) the annual kWh production (the expected output) and 2) the price.
Would you pay more for “more efficient” panels, if I told you I could get you a less expensive system that outputs more, fits on your property and lasts just as long?
PTC= PVUSA Testing Conditions (realistic test conditions)
Sqft= Square foot
Related Articles:
- SRoeCo’s sortable, searchable Solar Panel Comparison Table
- How to Choose the Best Solar Panel Value
- Solar Panel Comparison Article
November 7th, 2009 at 6:54 pm (#)
Ok…so im confused. Is a 200W Sanyo Panel the equivalent of say a 240 Evergreen based on its efficiency? If I install a 5KW system with 200W Sanyos or 240 Watt Evergreens - which system would produce more during the course of the year?
thx great website. Add more for us dummy laymen types!
December 22nd, 2009 at 7:45 pm (#)
Great questions Gordo. Generally, the PTC rating of the module (solar panel) is the best way to compare which panel will produce more during the course of the year. The PTC rating is a more realistic rating of the panels tested under real-world conditions as opposed to laboratory conditions.
Each 5 kW system will produce slightly different depending on many things (tilt, direction, shade, etc). The easiest way to compare systems is to have different solar companies give you free evaluations (proposals) on a system. After they explain everything, ask them what the “expected first-year output in kWh’s” is, and then you can see which system will produce more during the course of a year.
What kind of information can I add to help the dummy laymen types? I’m open to suggestions. My goal is to simplify solar as much as possible. Thanks for the comment!
January 25th, 2010 at 12:18 pm (#)
I’ve been talking to a local solar company, but I don’t feel I have quite enough information to take the solar leap. Some questions:
I’m looking at three systems; a Sunpower 235wt (24 panels), a Sunpower 210wt sytem (24 panels), and a Sharp 235wt sytem (22 panels). These are arranged in most-to-least expensive. Net costs after rebates, taxes,etc. range from about $24,000.00 to $22,000.00 to $19,000.00
One thing none of your charts considers is aesthetics. The all-black Sunpower panels are a lot better looking than the Sharps, and in this situation quite important. So, am I foolish looking at the more expensive systems, or does anyone else make a good-looking product?
How much wiggle room is there in these quotes? This cliff is pretty steep. I don’t know if I should jump now or wait until other companies come up with less industrial-looking systems.
Thanks for your imput Rick
January 25th, 2010 at 4:52 pm (#)
Glad to hear that you’re talking with a local installer. You’re correct: my charts do not include aesthetics. Beauty is in the eye of the beholder, no? It would be hard to scientifically measure aesthetics. However, you’re not the only person who has considered the looks of the system. Looks actually ends up being an important factor for many people. Your major differences in price of these three systems are going to come from their output, not their looks.
Sharp actually recently came out with the OnEnergy roof-mounted system with a “low-profile rack designed to blend beautifully with a home’s roofline”. Ask your installer if he can provide this system.
The cliff’s not as steep as you think. Solar panels are going to look like solar panels. Companies are focusing on improving efficiency and reducing cost much more so than they are working on aesthetics. Don’t wait for that reason. Plus, the sooner you take the plunge, the sooner you’ll reap the benefits!
As for wiggle-room, solar installers actually have low profit margins despite the news that it’s a booming business. The competition is strong (which is good for the consumer). The wiggle-room, if any, will be in the salesman’s commission. Talk to multiple installers, but remember - they’ve got to feed themselves too.
Good luck Rick!
February 4th, 2010 at 4:28 pm (#)
I’m looking for the highest wattage per square foot, but the price on the 20% efficient sanyos are $4 per watt.. Is there anything more efficient than these yet as your post is getting old… The more wattage per square foot the better.I am going to cover a car with them as much as I can to run a hydrogen generator, and I will need as much power as i can possibly fit into that space.
February 4th, 2010 at 6:01 pm (#)
My charts are currently up-to-date. There is nothing available on the market more efficient that what is listed. Anything more efficient has only been achieved in research laboratories and has yet to be available for the common consumer.
I will be sure to update these charts when new efficiencies are reached. However, don’t expect this to happen regularly. Solar cells are not equivalent to computer chips. Let us know how the car progresses!
February 18th, 2010 at 4:24 pm (#)
Where does this data come from?
Is it from the manufacturers, from a testing lab, or from real-world conditions?
If it is from real-world conditions, which part of the real world? Was the testing done in New Mexico or Maine, or somewhere in between? And if so, does it cover a full year cycle? Were all of the panels tested at the same location?
I know some panels behave better in low light conditions, some are more shade tolerant, heat tolerant etc. I would like to see some true side-by-side annual (or multi-year) results, especially if they come from the northeastern USA.
March 3rd, 2010 at 10:24 pm (#)
This data comes from the List of Eligible SB1 Guidelines Compliant Photovoltaic Modules used to receive California state rebates related to solar installations. It is from PV USA Testing conditions performed at a research facility in Davis, California. California is by far the state with the most solar installations at more than 530 megawatts (MW). New Jersey and Colorado are a distant 2nd and 3rd with 70.2 MW, and 35.7 MW installed respectively (according this Reuters report). This is why the current data is from California, and not the Northeastern USA.
The data is mainly for comparison purposes as the measurements are consistent. Local installers will have more information regarding local production output. My comparison charts are best used to confirm and/or ask about differences in output or efficiency.
–from List of Eligible SB1 Guidelines Compliant Photovoltaic Modules
March 5th, 2010 at 11:18 am (#)
I am confused. I live in So.Cal. and am getting estimates from 3 companies, the first, Solar City is going with the Kyocera panels (preliminarily), but I don’t see Kyocera listed on the California SB1 Compliant list. I also see that SunPower’s panels are more efficient. Since we are considering a PPA or lease, does it matter?
March 7th, 2010 at 1:22 am (#)
Hello
Nice chart! Very usefull.
Can I ask you why SunPower 300 and 315 are not included?
March 7th, 2010 at 10:35 pm (#)
Hello Matej,
Thank you. SunPower 300 and 315 are not included on the chart above because the chart is of “30 of the most common” solar panels used. The size and cost of the SunPower 300 and 315, though they are very efficient, cause them to be used in solar installation projects much less commonly than the panels listed. That’s why I have included a link to the 40 Most Efficient Panels available which includes both mentioned. Good question!
March 7th, 2010 at 10:49 pm (#)
Hi Jocelyn,
It doesn’t matter. A solar leasing or PPA (power purchase agreement) installer like Solar City can use whatever panels they want, because they will own the system, which means they receive the rebate (not you). Several Kyocera panels are listed on the CA SB1 Compliant List, and if you were buying a solar system from an installer in California, you should make sure that your equipment makes you eligible for the rebates. But since it’s a PPA, it doesn’t matter for you.
PPA’s or solar leasing are great ways to go solar, and as long as you feel you understand the terms and are getting a good deal (which you likely are) then you don’t need to worry about eligible or efficient equipment. You only buy the energy produced, and the provider will make sure that it installs solar panels that produce over the long-term, or they won’t make any money! So you don’t have to worry!
Thanks for the question! Glad you’re going solar! You’re going to be happy that you did!
March 18th, 2010 at 3:33 am (#)
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