Thread: 3 KW Solar system 7 year summary

We installed a 3kw unit just over 7 years ago & the inverter just packed up - 2 years out of warranty & according to the manufacturer ( & numerous forums) irreparable.
Attached a copy of an email I sent the installer which explains the situation after I got a quote for either $2600 or $3300 to replace it. Its been a week now with no reply.

Hi Marina,
Thanks for your quote.
I did some sums to see whether it is worth replacing the failed inverter.
I have closely monitored the savings from my Solar system over the 7 years of operation. Your company quoted average annual savings of 3428 kwh at the time of purchase & that was shown to be pretty honest & accurate. My system saved 25,300 KWH over the just on 7 years, so a bit more at 3671 kwh P.A.
Given the initial purchase price of $6184 and ongoing failures/maintenance ( ( 2 Isolators) & factoring in the various rebates & charges the system is not quite paid for yet, and that is not factoring in I could have put the money into a fixed interest account instead.
My internal consumption runs at around 30% so the annual ongoing savings are as follows
3628 x 30% = 1088 kwh @ 26.59 ( ie 26.86 plus 10% gst minus 10% pay on time discount) = $289.29
3628x 70% = 2539kwh @ 11.3 = $326.90
Total Solar savings per annum $616.19

Cost of replacing failed 7 year old invertor with a 5 year warranted unit $2600 Divided by savings of $616.19 = 4.21 years before any gain.
Cost of replacing “ “ “ “ with a 10 year warranted unit $3300 Divided by savings of $616.19 = 5.35 years before any gain

I haven’t factored in lost interest rates on the initial costs of 2.6 & 3.3k as it is only 2.6% at present and declining.

There needs to be some better incentive to keep an older system running. Unless the government can figure something out, or increase the rebate dramatically, it seems to me that I am in a never ending cycle of maintenance costs versus savings. There is also the possibility that neither your company nor the manufacturer would be around in 5 or 10 years to support me. Sorry to be cynical but it happens.
So as it stands, the solar system on my house will continue to sit disconnected and idle until things change.
Please feel free to pass this on to your management.

So it seems that getting in early wasn't so smart. Buying into one recently, especially given the crazy Vic Gov deal, would have been wiser. The initial rebate of 24/kw only lasted a year or so.

However, YouTube to the rescue !! - I found a clip done by a man in England who was in the same situation ( it seems these units are failing all over the world) whose attitude was "lets strip it down see what the failure is, after all, what is there to lose?" Now electronics are scary to me, but by opening some relays with a Dremel & some basic dobs of solder, it has now been working for a week, so, fingers crossed it has been fixed. I have to wonder just how many of these units are now unnecessarily in landfill.
Here is the repair.
https://www.youtube.com/watch?v=soRKUQtSfX0

David

Good job! I've resoldered joints on various equipment and a few times all solder joints in an area when I couldn't find the cracked culprit to get equipment working again.