Kyocera 205 vers 210 panels -- real world output??

cdherman · August 2009

I am obviously learning here. In looking around and speaking with some sellers, I have of course learned that some panels do better than others, as compared to the ratings.

For instance, I was told that the Kyocera 205 panel was about 180, but the 210 due to better technology is producing about 210 real world.

I heard that they had real world testing at "CEC" so I looked for that and found the site www.gosolarcalifornia.org but the ratings at that site only suggested that the 210 was producing 185 real world ratings.

So, can someone help me? Is the Kyocera 210 just 5 watts more than the 205, or are there other differences that I should be aware of that would influence my decisions?????

mike95490 · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

The difference is in the test method, like car mileage window stickers.

The STC test, is at room temp, with a flash tube, 90degrees angle,
"Best Conditions" 205W

in use, the panel is on a roof, baking in the sun, toasty hot. Sun somewhere in
the sky, at the wrong angle = 180W

BB. · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

The short answer--With Name Brand/good quality solar panels--they are all pretty much tested and rated the same way.

The "Marketing" rating (STC or Standard Test Conditions--or whatever the exact name is) is for a 77F temperature in a breeze.... Which in real life, makes the panel quite a bit cooler than what people see on a real rooftop installation.

So from the CEC database:

Kyocera Solar KD205GX-L 180 Watt CEC
Kyocera Solar KD210GX-L 184.6 Watt CED

The CEC rating is closer to real world temperatures (moderately warm weather on a rooftop). Since solar panels lose power output as they get warmer (specifically, the Vmp voltage falls as temperature increases)--the test conditions do significantly affect the ratings.

So--based on what I see here--there is no major difference in the panels. It could be something as simple at Kyocera has tweaked the product to get 2% more power--or the process is more stable and they are getting panels with a consitantly 2% higher yield and they can up the minimum spec.

In real life--it works out that if you take the panel rating and multiply by a 0.77 derating factor--that you will get (roughly) the real world average output (including temperature, dust, inverter/charge controller losses).

Since the physics is pretty much the same for all Silicon based panels (crystalline and amorphous)--all vendors have roughly the same derating issues.

-Bill

DLwindsun · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

The new Kyocera KD-210 modules have a zero tolerence rating. Kyocera is not going public with the ZT rating until 2010. The new rating is suppose to be a real world test rating of 210 watts.

niel · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

does this mean that the stc rating is much higher for the pv and that they are taking the initiative to move away from stc ratings?

BB. · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

It sounds more like going from +/-10% to -0% rating... The 20 year derating and STC/CEC deratings would still have to happen anyway because of physics.

If they started advertising the "useful" CEC power instead--they would get beaten up by everyone else on the $$$/Watt pricing... Hardly anyone would pay attention to the *** notes.

Otherwise, just wait and see.

-Bill

cdherman · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

So the current 205 panels have +/- 5% according to their specs and the 210 are speced the same way.

So is the *real* 210 more like 220 +/- 5% (kind of like saying that it is a 210 with a 10% over variance and zero percent under). Or is it just a 210 with much tigher variance, like +/- 1%

Does that make sense?

And what is better, a panel that has a very tight variance panel to panel, or panels that are just very conservatively rated, so that in a given lot, you can be assued that NONE of them are under their rating? Maybe it doesn't matter?

BB. · August 2009

Re: Kyocera 205 vers 210 panels -- real world output??

"Real" means that, at a minimum all panels will be -5% or more... The vendor charges by $$$/watt. So the higher the vendor can mark the product, the more money they make.

If they have the exact same panel, but have improved their manufacturing tolerance and sorting that the can now get 210 watt panels, they can make another $15 or so.

"Real" does not mean "real to you"... Real to you is based on your location, installation, your hardware (MPPT or PWM controller), etc...

There is no "one number" that applies... Panels get hot, they output less voltage. Panels get cold (and sun reflections from snow), they output higher voltage...

Remembering:

Power = Voltage * Current

Then you see that the correct charge controller (MPPT-Maximum Power Point Tracking) can take the above and:

Vmp * Imp of solar panels = Vbatt * Ibatt of the battery bank

For a Non-MPPT type charge controller--the equation looks like:

Ibatt based on voltage of solar panel = Ibatt of battery bank

And as long as Vmp of solar panel is > Vbatt charging -- then a Non-MPPT controller will still charge the battery just fine--but you will loose the 0%-15% (typical--in some cases you may get a bit more power) that a MPPT controller can recover from the variable Vmp of the solar panels.

There are lots of other reason to use an MPPT charge controller--but this was why they where originally designed and marketed.

-Bill

maccluer · February 2010

Re: Kyocera 205 vers 210 panels -- real world output??

Au contraire. My 205s on a cold day can (at 60 degree inclination) output in excess of 225 W, measured in any number of ways: by the PVP2000 (now that I have grid tied) or by past direct measurement into a resistive load (via my previous MPPT). Splendid panels!

Solar Guppy · February 2010

Re: Kyocera 205 vers 210 panels -- real world output??

your PVP2000 is likely showing optimistic power reading, the PVP's I tested reported values 5-10% above true power , a 205 watt panel won't be putting out 225 watts unless you live in the arctic or short term edge of cloud events

Cariboocoot · February 2010

Re: Kyocera 205 vers 210 panels -- real world output??

People get hung-up on numbers.
Solar panels produce according to the amount of light they're exposed to. The Wattage rating is a relative thing, really; if you put a 210 Watt panel next to a 205 Watt panel the output of the two will vary according to insolation, but the 210 will have that 'slight edge' over the 205.
In practical terms, panels put out an average of about 70% of their ratings during the 'usable sunlight' hours. That barring local shading and other factors of course.

But people do get hung-up on numbers. Obsessing over SG reading differences of 0.005 or battery Voltages of 0.1. In most cases it's practically impossible to get readings that accurate twice in a row from the same thing with the same meter.

You can use panel ratings to compare one to another (as in a price-per-Watt basis) and to plan roughly how many you'll need. But for the most part variations of 10% aren't that unusual or important.

Usually. I remember a certain timing circuit that had six components. If they each were off tolerance 10% in the right (or wrong) direction the circuit didn't function within specs, even though each part was technically within range.

Don't get overly concerned about small differences, and always allow margin for error.

tallgirl · February 2010

Re: Kyocera 205 vers 210 panels -- real world output??

Solar Guppy wrote: »

your PVP2000 is likely showing optimistic power reading, the PVP's I tested reported values 5-10% above true power , a 205 watt panel won't be putting out 225 watts unless you live in the arctic or short term edge of cloud events

Doesn't take Arctic temps to make 110% of nameplate. It's February and miserable cold all over the place. Knowing the overnight low temp would be helpful in figuring out how far from reality that reading is.

But more to the point, I've been seeing readings more than a few percentage points over nameplate from more than a few different panel makers. Wait until summer -- then we'll see who's still talking about panel output

newenergy · February 2010

Re: Kyocera 205 vers 210 panels -- real world output??

I don't know these particular models of modules, but when a manufacturer has some series of panels, isn't it just the case that they measure their output and then stamp them 200, 205, 210 or w/e depending on the output and however they want to show their tolerances?

Run on sentence and all, but aren't the 205s and the 210s just the same panels with the 210s testing a little better?

BB. · February 2010

Re: Kyocera 205 vers 210 panels -- real world output??

Probably yes (tighter manufacturing tolerances / more experience with process allow slightly higher MARKED average output).

-Bill

Braden · March 2010

Re: Kyocera 205 vers 210 panels -- real world output??

newenergy wrote: »

I don't know these particular models of modules, but when a manufacturer has some series of panels, isn't it just the case that they measure their output and then stamp them 200, 205, 210 or w/e depending on the output and however they want to show their tolerances?

Run on sentence and all, but aren't the 205s and the 210s just the same panels with the 210s testing a little better?

generally yes. And if that is the case with these panels and there is indeed a +/-5% Power Tolerance, that means the 205s are getting under 199.5W when tested by the manufacturer (if they were getting more, they would be within the -5% Power Tolerance of the 210s and then sold as such).

Keep in mind, the above is assuming the 205s and 210s are the same panel line with different testing and the power tolerance is +/-5%.

tallgirl · March 2010

Re: Kyocera 205 vers 210 panels -- real world output??

tallgirl wrote: »

Doesn't take Arctic temps to make 110% of nameplate. It's February and miserable cold all over the place. Knowing the overnight low temp would be helpful in figuring out how far from reality that reading is.

But more to the point, I've been seeing readings more than a few percentage points over nameplate from more than a few different panel makers. Wait until summer -- then we'll see who's still talking about panel output

Just a quick update -- after adjusting for our current distance from the sun, the 112% STC I was getting was really only 109%.

Kyocera 205 vers 210 panels -- real world output??

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