My 210Watt panels are not efficient or are they???

marcini
marcini Registered Users Posts: 7 ✭
in General Solar Power Topics #1
Hi Guys,
I'm brand new here so hi to all.
I purchased 4 210watt panels and have em in two strings of 24v connected to my 1200power jack grid tie inverter. I measure the amps on a sunny autumn day and was only getting about 13.7amps and about 30volts, so that makes it little over 400watts(my P3 watt meter connected to the inverter shows about 350W, but that's another story). They get direct sun, but lay flat on the roof of my shed, but I also tried them at an angle, facing direct sun from the south and results weren't any better. So my question is, are those panels really that crappy or this is normal, this whole system seems to be <50% efficient. here are the panel specs:

SUN A-210-fa3
Power (W) 210 Watts
Open Circuit Voltage (V) 22.80 Voc
Short Circuit Current (A) 12.11 Isc
Maximum Power Voltage (V) 18.30 Vmp
Maximum Power Current (A) 11.48 Imp
http://sunelec.com/index.php?main_page=product_info&products_id=377

Thanks for all your suggestions
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Comments

  • mr.radon
    mr.radon Solar Expert Posts: 158 ✭✭✭✭✭
    #2
    Re: My 210Watt panels are not efficient or are they???

    You don't mention where you live.
    The further we end up in winter the more southern the sun appears and the shorter the days are. So several factors are at play here. The sun being low on the horizon means there is more atmosphere to dissipate the light energy (Insolation is lower).
    You can look up the insolation values for your region this time of the year. Your panel was rated at STC (please check) which isn't very representative of what it will produce. However, it is easy to calculate from STC to your conditions.
    After going through the calculations I would then check each panel one at a time. Maybe you have an undetected defect in one.
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  • marcini
    marcini Registered Users Posts: 7 ✭
    #3
    Re: My 210Watt panels are not efficient or are they???

    I live on the east coast, NJ
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  • mr.radon
    mr.radon Solar Expert Posts: 158 ✭✭✭✭✭
    #4
    Re: My 210Watt panels are not efficient or are they???

    I think these are your panel specs:;)
    http://www.altestore.com/mmsolar/Others/ES-A_200_205_210-fa3_specsheet.pdf
    Also, they give the correction factors for the effects of temp. Measure the temp, figure out your insolance for the time of day (chart) and measure the angle of the panel, crank out the numbers.
    I think I've seen these panels, they are alright.

    Note the big difference between STC and NOCT. Notice that to get 210W you have to be at: 1000 W/m2 (Insolance), 25°C cell temperature, AM 1.5
    Verses 154W at: 800 W/m2, 20°C ambient temperature (cell temp is 45.4)

    They way you get this is 210W*800/1000=168W
    45.4-25=20.4 20.4*(-.43%)=-8.722%
    168*(1-.08722)=153.3W pretty close to the 154W.
    Using trig you can figure out the % change due to angles less then perfect.
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  • marcini
    marcini Registered Users Posts: 7 ✭
    #5
    Re: My 210Watt panels are not efficient or are they???

    thanks for all your replies, very informative. I know those panels are made for Sun electronics, not sure who makes them, but they might be what you posted there.
    I have to look more into those numbers, and also try to position them better, but that's probably gonna happen in the spring.

    P.S. Could you elaborate more on what the difference is in STC and NOTC and why the values differ so much, seems like the difference is really huge. How do they perform those tests.
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  • mr.radon
    mr.radon Solar Expert Posts: 158 ✭✭✭✭✭
    #6
    Re: My 210Watt panels are not efficient or are they???

    The tests are done in lab conditions:
    STC =1000 W/m2, 25°C cell temperature, AM 1.5
    NOCT=800 W/m2, 45.4°C cell temp, AM 1.5

    When you buy gas for your car the pump's meter is calibrated to STANDARD conditions. So when you buy gas on a really really really cold day you get more. (more dense, gas is sold by volume=more gas!)

    Same with solar panels. On a cold sunny day they make more then they are rated for. On a stinking hot sunny day they make far less.

    You have to educate yourself what causes solar panel output to fluctuate. Its a lot more then just shading and angle of the sun.

    Look at the label on your panel, post a picture if available, the label should have all the information you need to calculate the output from the panels given your conditions. (cell temp, angle of the sun, clouds, humidity, time of day, day of year, longitude/latitude) (you should ahve sized your inverter for the worst case day)
    But to really test them, you would have to take them to a lab where they would simulate STC or NOCT and then measure the output.
    Trust me all panels sold pretty much have been QA'd to death. When I bought my 45 panels I got the test reports from the manufacturer. When they make these little babies they have to match all the individual cells to make panels that work well together. You see if one panel isn't matched it affects the whole string, unless you use Enphase inverters. The panel manufactures don't want to sell unmatched panels. They would go out of business real quick, there is a lot of competition right now in the market.
    If you got these at a discount from a fly by night retailer, or they were marked "damaged" or the shipper beat them up you might have a problem, but I'm sure they left the factory making the listed power on the label.
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  • drees
    drees Solar Expert Posts: 482 ✭✭✭
    #7
    Re: My 210Watt panels are not efficient or are they???

    I suspect your non-UL listed grid-tie inverter.

    Get a real inverter before you fry something.

    Some comments on it:
    http://www.pakistan.tv/videos-power-jack-watt-grid-tie-[nONFr3RZaLk].cfm
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  • FL SUN
    FL SUN Solar Expert Posts: 94 ✭✭✭✭
    #8
    Re: My 210Watt panels are not efficient or are they???

    Did a Google on Power Jack inverters. Seems Ebay loves them. A lot of them are set up to output @ 50 hertz. (For the US market?) :confused:

    I stopped looking when I saw a Power Jack 3,000 watt 110v version. That's 27 amps into a single pole circuit. That's crazy insane. Most household 110 volt circuits are usually 15 amps.

    I would give a wide berth to this brand as well. Your modules and inverter are not UL listed. If your set-up catches on fire and burns down your house, you will not be in the graces of your homeowners insurance. Be careful.
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  • icarus
    icarus Solar Expert Posts: 5,436 ✭✭✭✭
    #9
    Re: My 210Watt panels are not efficient or are they???

    I think they rate right up (down) there with BZ controllers:

    http://ludens.cl/Electron/chinverter/chinverter.html

    http://inverter.115.at/powerjack-300w-grid-tie-inverter-modifications/

    We assume that you have no permits for your installation? Are you grid tied?

    Tony
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  • marcini
    marcini Registered Users Posts: 7 ✭
    #10
    Re: My 210Watt panels are not efficient or are they???

    Ok then, at the moment I use that 1200 watt PJ inverter with my 4modules together rated to be 840watts, if i was to use better Grid tie inverter with my existing panels and add 2 of those (schott solar 300watters) since I already have them, just not hooked up to anything(that would total roughly 1.2KW, what grid tie inverter would you recommend??
    Thanks
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  • dwh
    dwh Solar Expert Posts: 1,341 ✭✭✭
    #11
    Re: My 210Watt panels are not efficient or are they???

    The problem is that you are using a plug-in inverter. These are not UL listed, and almost certainly violate the rules of your electric company - they get to decide what generating equipment is allowed to be connected to their grid.

    A PROPER grid-tie installation will require a UL listed inverter, installed as per National Electrical Code with appropriate wiring, breakers, disconnects, permits, inspections, etc.

    If you are in the US, then you are on shaky ground using a plug-in inverter - basically, it's doesn't meet code and it's not legal. They haven't been outright banned yet, so it's a grey area loophole. But eventually, they will almost certainly be explicitly outlawed.

    Sorry, can't give you a recommendation for a better one - the best recommendation I can give you is don't use a plug-in grid-tie inverter.


    Also, you can get an idea of Power Jack products quality here:

    http://ludens.cl/Electron/chinverter/chinverter.html
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  • drees
    drees Solar Expert Posts: 482 ✭✭✭
    #12
    Re: My 210Watt panels are not efficient or are they???
    marcini wrote: »
    Ok then, at the moment I use that 1200 watt PJ inverter with my 4modules together rated to be 840watts, if i was to use better Grid tie inverter with my existing panels and add 2 of those (schott solar 300watters) since I already have them, just not hooked up to anything(that would total roughly 1.2KW, what grid tie inverter would you recommend??
    Thanks
    I don't see an easy way to combine all 6 of your panels together into one grid-tie inverter.

    I also don't see any grid-tie inverters that will work well with any combination of panels you have - maybe the others will have an idea...
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  • mr.radon
    mr.radon Solar Expert Posts: 158 ✭✭✭✭✭
    #13
    Re: My 210Watt panels are not efficient or are they???

    OMG I looked at that inverter. No way would that thing ever get plugged into in my house. Did you pull an electrical permit and get a signed Netmeter agreement?
    If not you had better hope your utility doesn't catch on to what you are doing.

    As dumb as some of the rules are, they should be followed.

    On the panels I found the link to the web site. I read this:
    Unlike most other brands which have power specifications within +/- 10%, these modules have power specifications within +-5%!

    I would RUN from these panels. My cheap (REC Solar 225W) panels have a deviation of +-0.5%! Your panels vary by more then 10 times this... so you can have a panel at +5% another at -5%....No good.
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #14
    Re: My 210Watt panels are not efficient or are they???

    This is scary!
    http://www.blujay.com/item/POWER-JACK-GRID-TIE-POWER-INVERTER-3000-6000-WATTS-8120000-3372335&keywords=

    A 3000 watt gridtie inverter that they want you to plug in any outlet in your house. Hope these guy have good product liability insurance.

    Hope the homeowner has a fast 911 system.
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  • BB.
    BB. Super Moderators, Administrators Posts: 33,613 admin
    #15
    Re: My 210Watt panels are not efficient or are they???

    I am not even sure it is a real product/website or if it is some scam. Perhaps just a bad job of editing the product page...

    Whatever it is--pick your specification (all from the same page):
    • 6000 Watt max. 3000 Watt...90-130v AC, 60Hz
    • Power Jack-POWER JACK GRID TIE INVERTER 600/1200 WATTS MAX
    • Power Jack 3000W GRID TIE INVERTER...Output 90V-130V
    • 3000W...AC Output Voltage AC190-250V Frequency 60Hz/50Hz

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • FL SUN
    FL SUN Solar Expert Posts: 94 ✭✭✭✭
    #16
    Re: My 210Watt panels are not efficient or are they???

    Those particular Evergreen modules have these tolerance specs:
    Ptolerance -0/+4.99 W

    The tolerance on the rebranded Sun modules is the same, according to their claim of having the same specs as the A modules. The only difference is lack of UL listing.

    I have heard a lot positive input on how well those modules (Evergreen/Sun) perform. Whether one chooses to use the Evergreens or Suns is up to the end user regarding the job's UL requirements.

    The Power Jack family of inverters is another story. Their specs look like they were translated directly from Chinese. All the misspelled words and lack of concrete data to the consumer tell me to look somewhere else for inverters.
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  • techntrek
    techntrek Solar Expert Posts: 1,372 ✭✭✭
    #17
    Re: My 210Watt panels are not efficient or are they???

    I took a look at the Ludens site dwh posted above - he has lots of good stuff there (other than the excellent write-up on the dozen+ problems with that Power Jack).

    Note, the Power Jack is not a plug-in grid-tie inverter, its designed to be a UPS/offgrid. Of course 3000 watts is still way too much for a 15 amp plug...
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
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  • solar_dave
    solar_dave Solar Expert Posts: 2,397 ✭✭✭✭
    #18
    Re: My 210Watt panels are not efficient or are they???
    techntrek wrote: »
    I took a look at the Ludens site dwh posted above - he has lots of good stuff there (other than the excellent write-up on the dozen+ problems with that Power Jack).

    Note, the Power Jack is not a plug-in grid-tie inverter, its designed to be a UPS/offgrid. Of course 3000 watts is still way too much for a 15 amp plug...
    From the site I quoted
    Features:
    1. power jack grid tie inverter is designed for small solar panel & wind energy market, it's suitable for family enengy system.
    2. this inverter can directly use solar panel, wind charger through inverter to home grid.
    3. easy to installation, just need solar panel, grid tie inverter, then directly can put into home grid.

    note: this inverter only has grid tie inverter function, do not have tranditional inverter function, pls do not connect the battery for 12v dc source, for further questions, pls leave message to ask, tks.

    1.idea for power jack
    The inverter can be connected to any outlet at home, when this line run by the conventional electric network. The inverter IC will monitors the volume, frequency and phase of the home grid, then produce a pure sine wave that the frequency and phase will be match the grid's, and the volume will be higher than the grid's, then according to our current controlled PWM, to control the output power to the grid. The inverter will puts out power when the home grid is on.
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