Our local school which I try to support has applied for the NSSP grant and intends to install a 3,4 kw PV system.The quote it received of SolarGen (www.solargen.com.au)consists of 17 202 Watts Schott Poly-crystalline panels and a power one Aurora 3.6kw inverter.Has anyone any experience/comments in regards to the inverter and/or panels which seem not to be one of the common model/type used in Australia.
Thanks,
PV inverter
(7 posts) (3 voices)-
norbert
MemberPosted Saturday 7 Mar 2009 @ 3:15:09 am from IP # -
Sunshine
MemberNorbert
I haven't heard of Aurora inverters either, but a quick look at http://www.solarinverters.com.au shows the Aurora inverter has an amazing input range of 90-580 volts which other inverters can't match. This means you are much more flexible in types and quantity of panels than what other inverters can match.
I have 18x 170w Schott poly-crystalline panels installed, the other day I broke my solar production record, with 19.2kWh produced in a day, so they are working very well.
They are more expensive than other brands available, but Schott has a solar PV history starting back 51 years ago, so they are a reliable and respected name in solar PV.
I know that the company who installed my system advised me that the installations they were doing for schools in the Brisbane area apparently had to be Schott panels.
I don't know if this is a written requirement of the NSSP or the education department?
He also said Schott were mainly specified in commercial applications and also be architects.Posted Saturday 7 Mar 2009 @ 5:16:00 am from IP # -
norbert
MemberI'm getting a bit confused,what does the input range actually mean?
The Fronius IG 30 which I intended to buy for my installation has a MPP voltage range of 150-400 V whereas the Aurora has an input range of 90-580 V.
The Sunpower SPR 210W panels I've bought have a rated voltage of 40V.I've purchased 9 so far and I was thinking of buying another 3 so a total of 12 which would bring the output to 2520 Watts.I believed this would be ok for the inverter as the IG 30 has a nominal output of 2500W and a max output of 2650W.Yesterday I spoke to an installer and he said before buying an inverter I need to make sure that the voltage of the inverter suits the panels???
Was I wrong in thinking that what matters is the watts (output)of the inverter?
How does the voltage come into play and would the IG 30 be ok for my proposed 12 panels?
Thanks for any advise.Posted Friday 13 Mar 2009 @ 4:51:41 pm from IP # -
Sunshine
MemberNorbert,
The issue is PV panels don't always have a constant voltage output. Their voltage output varies greatly due to the amount of sun, directon, tilt, and most importantly temperature.
I have calculated that nine Sunpower SPR 210w panels will have the following voltage outputs, at the following temperatures.
Minus 10 degrees=473v, at 15 degrees=372v, at 50 degrees=329v and at 70 degrees=305v.
As you can see the lower the temperature, the higher the voltage (and also power in watts). If the voltage gets too high (due to low temperature), you don't want to fry the inverter, and if the temperature of the panel in summer gets too hot (yes, they get quite hot in the sun), you don't want the inverter to cut out in the middle of the day, if the panel voltage output ( read inverter input)drops too low, meaning you miss out on electricity production at the time of the day where the yield can be potentially high.As you can see it is quite easy for the panels to go outside the range of what the inverter can handle, due to the fluctuations in voltage due to temperature. The installer will be able to advise what configuration of brand/model of PV panels will match the model inverter.
The installer may be able to configure two runs of six panels each, which may be more suitable in keeping the correct voltage range.
Yes, total power output of all panels is important as well (and more easily calculated), but keeping the voltage in the correct range is more complex and important really.Posted Saturday 14 Mar 2009 @ 12:07:08 pm from IP # -
Solgen
MemberI had 1.8kW system installed 10 days ago and today the inverter (Latronics) died. Not impressed! Today was probably the brightest and sunniest day since it went in to service and for the first time the system may have gone to 100% output, I had only seen 75% max so far. If that is the case the inverter (2.5kW) may have been overrated or just plain faulty.
The supplier has advised that they will replace it in a week or so!
From my experience and other discussions, I get the feeling that inverters are the weak link in solar systems. Is that a correct assumption?Posted Monday 16 Mar 2009 @ 6:34:44 am from IP # -
norbert
MemberSolgen
I've bought Sunpower panels and was just about to order a Fronius IG 30 and now go through all sorts of trouble.A installers called me today saying he won't touch Sunpower panels because they require to be positivley earthed as they build up static and this is done via the inverter which needs to be modified,bla bla bla end quote.
I have contacted the place where I purchased the panels from and they confirmed that the inverter needs a positive earth kit and the only inverter to use is the SMA.There was no word about that when I bought the panels.I then contacted Sunpower Australia and they also confirmed that the inverter needs to be modified but this can also be done with the Fronius and not only the SMA.
If that particular installer wouldn't have told me I wouldn't have had a clue that the brand of panels I bought(I believe the only brand in Australia)requires the inverter to be modified.Neither the panel manufacturer or the place I purchased the panels from bothered to provide proper information.I then contacted the(accredited) installer I intended to give the job and he said he never heard of the positive earth thing either.I don't know whether you bought a kit or like me shopped around and got the main bits(panels,inverter)yourself in order to save money and then paid an installer to do the job. But knowing what I know know I would agree that the inverter can be and probably is the critical part and potential weak link of the system.As Sunshine said not only the watts but the voltage output matters as well so trying to save some bucks going for a cheaper inverter is probably a bit of a gamble.I briefly looked at the Latronics but the difference in price to a Fronius or SMA made me a bit suspicious as I believed the lower cost (some $ 1300) could possible compromise the quality.What put me off the Latronics as well was the huge weight 22 kg in comparison to 12 kg for the Fronius.Also Latronics only offered a 3 year warranty whereas Fronius or SMA are 5 years or an extended 10years for the SMA if you're prepared to pay extra.Posted Monday 16 Mar 2009 @ 6:07:41 pm from IP # -
Solgen
MemberThank you Norbet for your comments. I bought my system as a complete package with installation included, however, the quote did include an SMA inverter but a Latronics was installed instead, your advice re costs is why the substitution was made. I will now insist that the replacement is a SMA product.
I am using Sharp panels and have not heard about the earthing issue either.Posted Saturday 21 Mar 2009 @ 2:17:30 am from IP #