Currently Have 8yo system - Replace or Add to it?

Existing System

  • 8 yr old 3.5kw system (installed Sep 2011 by previous owners)
  • Inverter - SMA Sunny Boy (SB 3000TL-20) 3kw
  • 14 x 250w SRP (BBPV-250V) facing NE
  • 2 story, 4 adults, 2 teens, 1 x Pool, no Air Con
  • Our daily usage averages between 18 - 26kw per day depending on time of year and vacation absences, but that figure does not take into account what we consume from our current solar as ther is no way to monitor it.
  • Producing 2 to 2.6kw (See below - that was Midday on an overcast day)

Future household plans

  • Hot Water to be taken over by the new solar installation (currently Off Peak)
  • AC installation (possibly 6 x Split units, 2 - 3 years away)
  • Battery backup optional (if & when more affordable)
  • Off grid some day - (nice to have but not essential)

Quote 1 - Installer A (11.2kw system)

Item Specification Price (inc. GST)
Panels 38 x SOLAWATT Vision-60M 295w $-
Inverter 2 x SMA Sunny Boy 5.0-1AV-41 $-
Racking: Grace Rail $-
Installation: Full Installation $-
Other: SMA home manager 2.0-install back of meter box.
Replace power point on din w/HWT.
Additional charges: Hot water timer installed $ 200
Removal of old system to be left for owner disposal $ 300

System Price ______________________________________________$ 20,066

Less STC incentive 170 certs @ $34.70 _________________________$5,899

Total Price: ________________________ _______________________$ 14,167

Quote 2 - Installer A (Option 2 - 6.6kw System)

Item Specification Price (inc. GST)
Panels 22 x SOLAWATT Vision-60M 295w $-
Inverter: 1 x SMA Sunny Boy 5.0-1AV-41 $-
Racking: Grace Rail $-
Installation: Full Installation $-
Other: Replace power point on din w/HWT.
Additional charges: Hot water timer installed $ 200
Removal of old system to be left for owner disposal $ 300

System Price ___________________________________________$ 11,069

Less STC incentive 98 certs @ $34.70 _______________________$3,400

Total Price: _____________________________________________$ 7,669

Quote 3 - Installer B (6.6kw System)

Description Quantity Price (Incl GST )
20 x 330W Seraphim Blade Solar Panels - 6.6kW 1.00
Sungrow 5kw Single Phase SG5K-D 1.00
Sungrow Energy Meter 1 phase 1.00
Solar Racking - Tin Per Panel 20.00
Discount $ 2000.00 $ (2,000)

Total System Cost Before STC Incentives ________________$ 8,597

GST Included $ _______________________________________$782

Less 100 STC’s @ 35.50 ____________________________$ 3,550

Total Price After STC Incentives/Discounts _______________$ 5,047

My concerns

  • Why remove the old system? Its small and I can’t get monitoring on it but works fine. Adding a 6.6kw to it would give me 10kw of total solar. The installer at Quote 3 said they would retain it.
  • SMA have a reputation for reliability, and the warranty is great, but the rare failures that occur result in replacement with a Reconditioned unit NOT A NEW UNIT.
  • The SMA mobile App (Sunny Portal) is still very limited and does not provide real time or direct system monitoring and has very limited functionality. Check out the ratings on the App Store. Absolutely abysmal. Not that I would base my decision purely on the app, but is the Fronius App any better?

Quote 1

  • Do I need 11.2kw? Even with my future plans ?? Does it sound over the top?

Quote 2

  • This may be the option that I end up choosing but with a couple of mods.
    • Keep my existing system
    • Change to a Fronius ??? Opinions???

Quote 3

  • Not impressed with the Seraphim panels or the Sungrow inverter. At least according to the online reviews. SOLAWATT seem to get a better rap online. As for the Sungrow, It’s not even a contest. SMA, or even better, Fronius I think. Opinions?
  • The $2000 discount sounds phony. The system has probably been jacked up to start with.

Any opinions welcome and appreciated

Cheers

Peter

Hi @Pedro61

Interesting one!

Firstly, I agree, why get rid of a perfectly good solar system? Doesn’t make any sense. That’s just a damn waste.

Where abouts are you located? Your current system is probably producing about 12kWh per day on average. So if you are buying 18-26kWh per day, I guess you’re using 30-38kWh. That seems like a lot, but then with 6ppl and a pool…

So, like you say, adding 6.6kW gives you 10kW, and that will produce about 40kWh, which will cover your current usage. Adding AC will change things, but you don’t necessarily need to wipe your whole bill right? Do you have virtually unlimited roof space, or is that a consideration. 10-15kW of solar takes up a lot of roof.

The SMA home manager in quote 1 is more than just a phone app. We’ve got more details about energy monitoring in our solar inverter review article, and also links to further details in some spots:

  • The $2000 discount sounds phony. The system has probably been jacked up to start with.

Agreed.

I would vote for a 6.6kW system, but not this one. You might want to find the company that you want to work with, and then discuss with them what you actually want.

Hope that helps.

Cheers
Marty

Thanks Marty

We live on the Sunshine Coast QLD.

I contacted the supplier of the first two quotes asking him to rework the quote with us keeping the old system. Below is an image of the reworked roof layout he sent me today with a new quote. The yellow panels are my existing system.

He’s added another 5 panels now (I didn’t ask for the extra panels this time around, so not sure why he did that). But because there are more of them 27 now (SolarWatt - Vision 60M 295W) instead of 22, the final quote with the original SMA 6kw inverter is now $9999. Ill be calling them tomorrow to ask why the extra panels. Maybe he’s trying to cater for the future AC units, but like you say, if I only manage to reduce my bill to $100 bucks a quarter It’s still a win. Does $10k sound Ok for this system

Also - what is your opinion of the SOLARWATT panels? Their warranty is certainly impressive.

Thanks

Peter

Hi Peter,

I think that looks ok. I can see why they wanted to take down your old system, it’s the only way to sell a bigger new system.

You could definitely get that system cheaper, but you also often get what you pay for.

Cheers
Marty