Quote for 8kw Trina modules - how does it look?

Hi All. I’ve just received this quote. How does it look price wise? Keeping in mind they are getting rid of a 7.5kw system I bought from a company that now no longer exists (SAMIL Power). And what are your thoughts on the estimated payback time?

I have a north facing roof with a pretty standard sloped, dark tiles.

Not wanting to make the same mistake… I believe Trina are good too, yeah?


Panel Brand and Type - 24 x Trina 330w modules
System Size - 7.92W (produces on average 31.68Wh/day; 11,563.2kWh/year)
Configuration - TBA
Inverter Brand and Size - 24 x Enphase IQ7+ Micro-inverters
Total excluding GST 14,670.72 GST Amount 1,467.07
Total including GST $ 16,137.79
STC Rebate 131 x 35* 4,585.00
Total Price to Customer $ 11,552.79

Average annual savings @ 35c kW/h is $4,047.12. Payback period is approximately 2.8 years.
Assuming additional 10% efficiency, payback period is approximately 2.5 years.
Assuming additional 20% efficiency, payback period is approximately 2.2 years.
This price assumed standard installation without tilt.
This price includes removal and disposal of existing system.
This system includes the wireless communication / monitoring via the Envoy-S Metered.
This system is battery-ready for the Enphase Storage Systems which is our preferred option for load

Hi @slats

Samil inverters is one of the reasons I started this website. I thought they were good, and then they just started dropping like flies. Enphase is certainly a great choice if you don’t want issues like that again. I think Trina is a fine choice for panels also.

Considering the removal of the old system, price seems fine.

Regarding payback, where does the 35c come from? Is that based on what you are paying for power, or what you’ll receive when you export, or a mixture of the two? I imagine it’s pretty straight forward calculation given you’ve had a system on your roof for a while.


Hi Marty,

Sad to hear that SAML is one of the root causes… but good on you for starting this site! I recon I’m a grand or two short of getting my money back on the original system. Not the end of the world - but boy it’s great to have a resource like yours (as well as a lot more general info on the web) to help with making the right decision.

Great question on the 35c. I’ve followed up on that as even though I’m with pooled energy, and my rates are relatively high, they are still only 26.8c / kwh. It makes the whole quote look dodgy doesn’t it.

I’ll let you know what I get back.

Hay - any recommendations for installers in syd northern beaches?


Hey Matt

It’s not necessarily dodgy, just would be good to understand where they get the figure from. Do you know how much you were saving per year with the Samil system? It won’t be much different. I notice they have figures in there for an extra 10-20% efficiency with Enphase, and you can probably hope for an extra 10% at least.

We’re working on getting a network of trusted installers around the place, but don’t have much at the moment.

You can see if Banana Solar will go up your way, they are on the forum and seem pretty switched on: