We're going solar!

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#3385367 18-Jun-2025 20:43

Yeah. But for June so far instead of 11.1 we're averaging 17.2kwh produced per day, so it's a good year I guess. It has been quite clear skies and sunny, just freezing.

cddt

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#3385396 19-Jun-2025 08:25

kiwifidget:

Is this the same thing?

Yes! Maximum distance from the sun.

My referral links: BigPipe | Mercury

CYaBro

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#3385400 19-Jun-2025 08:59

We're finally getting solar!
Install scheduled for the end of July.

10kWp panels.
10kW Sigenergy inverter.
16kWh Sigenergy battery (2x8kWh)
Shelly relay for hot water control.

$35k.

Opinions are my own and not the views of my employer.

timmmay

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#3385406 19-Jun-2025 09:28

CYaBro:

We're finally getting solar!
Install scheduled for the end of July.

10kWp panels.
10kW Sigenergy inverter.
16kWh Sigenergy battery (2x8kWh)
Shelly relay for hot water control.

$35k.

Looks good :) You could get away with a smaller inverter which might be a little cheaper.

Inverters are usually undersized compared with panels because 10kw panels will only generate 10kw at the height of summer in peak sun. Most of the time you'll get less than that, and I've read that inverters operate most efficiently near their rated capacity. In Australia there's a regulation that you can put 133% solar capacity above the inverter capacity - so a 10kw inverter can support 13kw of panels. Ours is smaller, 6kw inverter with 9kw of panels. We did reach 6kw output quite a bit April but it's rare in May and almost never happens in June where we are.

CYaBro

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#3385474 19-Jun-2025 11:43

timmmay:

Looks good :) You could get away with a smaller inverter which might be a little cheaper.

Inverters are usually undersized compared with panels because 10kw panels will only generate 10kw at the height of summer in peak sun. Most of the time you'll get less than that, and I've read that inverters operate most efficiently near their rated capacity. In Australia there's a regulation that you can put 133% solar capacity above the inverter capacity - so a 10kw inverter can support 13kw of panels. Ours is smaller, 6kw inverter with 9kw of panels. We did reach 6kw output quite a bit April but it's rare in May and almost never happens in June where we are.

8kW inverter was only about $300 cheaper.

It also means if there is a power outage we can still output up to 9kW from the batteries as the power output is 4.5kW from each battery.

Installer also mentioned that the inverters run most efficiently at the nominal DC input voltage on each MPPT, which for the Sig is 350V.
Size of the inverter doesn't affect efficiency apparently.

Opinions are my own and not the views of my employer.

timmmay

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#3385534 19-Jun-2025 13:17

Makes sense. I tried to upgrade inverters from 6kw to 8kw but I was too late, the installer had already purchased it. We might lose a bit of peak production but it'll still do pretty well. Your system looks good :) What was your motivation for getting batteries? We didn't get them as our mains supply is reliable and the payback period is really long.

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kiwifidget

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#3385539 19-Jun-2025 13:30

If the inverter is 10kW, and ours is, then that is the max that can be fed to the house-battery-grid at any given moment, regardless of what the panels are producing at that given moment? Producing this table mountain graphic?

On that day the max value recorded for solar is 11.25kW, but the highest I have seen is 16.12kW at 1pm on March 3.

It didnt stay that high for long, was quite a patchy day sunshine-wise.

But thats well in excess of the 10kW inverter, so how did that happen?

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Jase2985

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#3385593 19-Jun-2025 19:24

10kW is AC power, some inverters can put the DC power off the panels straight into the batteries with no inversion necessary so can usually go over the max rating by a bit.

Your battery is charged by 11am in that image and you are hitting your max export for near on 5 hours so that's a lot of wasted generation even with a battery. could really go another battery or 2.