Solar Panels

[p--and--t]

I'm learning; Google results (so there, must be true) indicate that having more panel kw than the inverter, undersizing, is allowed in au to 133%, and may actually be desirable for efficiency.

Yep. I have 13.3 theoretical on the roof in 4 strings and twin 5kw inverters. There are a several reasons why at certain times of the day on various days the system does not operate at full capacity (clouds, shadows, rain, dirty panels, faulty panel effecting the string) so more panel capacity than inverter capacity is the norm according to my installer. I couldn’t have more inverter capacity as I am on single phase and Energex rules forbid it.

My kit is Sungrow/Jinko Tiger Neo. Installed by suresolar who were recommended and seem both knowledgeable and ethical.

 

[moa999]

Think these days with the relatively cheap cost of panels vav inverter capacity that 20-40% oversized is recommended. You clip in the summer sunny days but it maximises production during winter or cloudy days.

Also depending on roof less of a focus on pure north facing, most people would be advantage by a decent amount of West panels given late afternoon a/c and appliance usage.

 

[kookaburra75]

Watching the discussion on panels and cleaning etc... and sharing our experiences.

We originally went through Clean Power Australia in June 2022, one of the companies being promoted by the ACT Govt, as installers and therefore eligible for the $7500 per household rebate. MrsK got in contact, and they sent around one of their engineers in the evening as they had a shortage of sales people. He was more than happy to answer my questions about brand of panels, wiring, warranties etc - gained from the advice on this forum and some CSIRO people I know in this field. We had a chat about batteries, but his advice was not to get one at this stage and to wait a couple of years.
They use Hyundai panels, which come with a warranty that the panels will still be at 85% output after 10 years. He squeezed on 24 panels onto our roof, giving us 8kW, and you can see that some are on the south facing part of the roof. But they still have sunlight on them through pretty much through the whole day. They installed an 8kW Sungrow Invertor to with it.

We have a large claret ash in the northwest corner of the yard, which starts putting shade onto the panels from 2pm onwards. In the winter, that's not an issue, and that's when we need to get the most from the solar system. The best I have seen from the system is 7.5kW, which I'm more than happy with.

The communications through the sales, and then lead-in to the installation was excellent. Their team turned up on the day, in late June, about zero degrees, windy and sleeting, but they got it all done that morning and off to the next job.

I noticed that the grime was starting to build up on the panels. In Canberra we get showers from time to time, and then wind, which brings in dust, which then gets baked on in the next shower. After experimenting with different (and safe) options, I went with this brush and pole kit. It's held up well over the past 18 months of use.

 

[DejaBrew]

Got my first quarterly bill with full solar assistance. Given the coughpy FIT, I'm pretty stoked with the results! Knocked about 2/3 of the bill off compared to same time last year, and I reckon we worked the A/C much harder this time around. Was hoping for $0 bills, but that was perhaps a little unrealistic given supply charges, aforementioned coughpy FIT etc etc. Still, massive improvement over what we've been used to paying.

 

[Quickstatus]

With the 30% battery rebate from 1 July.
I got a quote for installation of a 3 phase 48kWh battery and 20kW hybrid inverter for $20500

Cost of storing then releasing electricity from a battery is circa 22c/kWh.

Assumptions:
opportunity cost over 10yrs,
amortising period 10yrs.
Maximum throughout as per warranty of 196800kWh over 10yrs
90% charging each day,
10% charging and discharging losses,
15% degradation at year 10. Loss
of Feed in tariff of 5c/kWh due to charging battery from solar).

Battery = SigEnergy

 

[TheRealTMA]

With the 30% battery rebate from 1 July.
I got a quote for installation of a 3 phase 48kWh battery and 20kW hybrid inverter for $20500

Cost of storing then releasing electricity from a battery is circa 22c/kWh.

Assumptions:
opportunity cost over 10yrs,
amortising period 10yrs.
Maximum throughout as per warranty of 196800kWh over 10yrs
90% charging each day,
10% charging and discharging losses,
15% degradation at year 10. Loss
of Feed in tariff of 5c/kWh due to charging battery from solar).

Battery = SigEnergy

22c is not much less than we pay for normal electricity bill without solar or battery.

 

[DejaBrew]

With the 30% battery rebate from 1 July.
I got a quote for installation of a 3 phase 48kWh battery and 20kW hybrid inverter for $20500

Cost of storing then releasing electricity from a battery is circa 22c/kWh.

Assumptions:
opportunity cost over 10yrs,
amortising period 10yrs.
Maximum throughout as per warranty of 196800kWh over 10yrs
90% charging each day,
10% charging and discharging losses,
15% degradation at year 10. Loss
of Feed in tariff of 5c/kWh due to charging battery from solar).

Battery = SigEnergy

48kWh? Do you truly need that much? (Genuine question)

 

[Quickstatus]

is not much less than we pay for normal electricity bill without solar or battery

It is for me. Peak tariff 48c/kWh . Shoulder 28c/kWh

 

[Quickstatus]

Do you truly need that much?

In winter it would be a little more than needed to cover peak tariff period

I'm analysing the historic data at a more granular level to get a more accurate answer. But July 2024 there was 4MWh electricity consumption total for month.

One of the issues is there is existing load shifting away from peak tariff period. Moving loads back will require some estimation.

As 22c/kWh is less than Peak and shoulder period, 48kWh will still be Ok, can go higher but >50kWh not eligible for 30% rebate

As it is a modular system of 6 x 8kWh. I could go with less then add if I actually need more.

 

[DejaBrew]

As it is a modular system of 6 x 8kWh. I could go with less then add if I actually need more.

I'll be doing the same sort of calculations in due course. Batteries weren't on my agenda until Labor made their announcement and got themselves re-elected. My issue is that I haven't had solar for a full 12 months so as of right now, I'll be needing to make some assumptions.

 

[Quickstatus]

solar for a full 12 months

You only need to dimension it for winter as that is the period where your electricity use is highest (assuming you don't have gas heating)

What's your array and inverter size?
And is your inverter grid tied?

 

[DejaBrew]

You only need to dimension it for winter as that is the period where your electricity use is highest (assuming you don't have gas heating)

What's your array sand inverter size?
And is your inverter grid tied?

I have gas cooking/water/heating, but anticipate I'll use reverse cycle (ducted) A/C more this winter as it's my first with the panels. 3 phase 14kWh micro inverter system feeding back to the grid.

 

[DC3]

Batteries weren't on my agenda until Labor made their announcement …

That got people thinking, didn’t it?

 

[Quickstatus]

this winter as it's my first with the panels.

If you have been with your electricity provider last winter, you should have consumption data in your online account - monthly/daily/hourly to help with estimation for July 2024