New installation

[karlboldy0]

Hi there,

We have an existing 1kw solar setup which was on the house from new by the developers. Pretty useful setup but better than nothing.

Recently just had installed a 5kw (12x 410watt) panels, with 3.3kw battery and EV charger. The setup is growatt, with the team being very professional when they install it.

Monitoring both systems, we seem to hit a wall at 4kw generation and can’t get past it. The roof faces south and gets direct sunlight with no trees or shadows. When I compare. It’s side by side there is a 10% difference in the generation capability of the existing install over the new one.
Is this normal? Could it be the recent heat?

Just keen to make sure we are getting all the bang for our buck.

 

[Si_Oakwood]

hi, could I ask what model your inverter is please? Could 4k be it's maximum output? I also have a new growatt system (east/west roof) but my SPH 3600 (max 16A) can only produce about 3.8kwh, so the solar generation starts to go up in the morning then plateaus for several hours.

 

[karlboldy0]

hi, could I ask what model your inverter is please? Could 4k be it's maximum output? I also have a new growatt system (east/west roof) but my SPH 3600 (max 16A) can only produce about 3.8kwh, so the solar generation starts to go up in the morning then plateaus for several hours.View attachment 13764

Thanks for the reply. The inverter is Growatt5500-MTL-S and should be capable of upto 5.5kw is my understanding. It’s couple with growatt SPA SPA3000TL BL which controls what goes where and charges the battery.
When I look at the panel on the inverter the max I’ve read is 3900 which matched the monitoring app.

 

[Bob Smith]

Typical houses will be on a single phase. This means that the DNO will only authorize (without asking for a special authorisation) to install a microgeneration system that will not exceed the power of a single phase ie 16A x 230V = 3.68kW.
In your paperwork you should have received a copy of the G68 form and/or MSC certification that will state the declared power of the system.

Therefore if your system is to comply with the requirement (not to ask for special authorisation) it must stay within the limit.
In other words your system has been oversized (which is not a bad thing) but will cap the power to this limit.

Hope this helps.

 

[Murdoch]

Sounds like it’s limited to the maximum output allowed by the dno

why would you need higher output?

houses use about 0.3 kWh on average

 

[karlboldy0]

Thanks for the responses - currently waiting for the paperwork for the installer to confirm.
The DNO isn’t something I’m familiar with, is this a soft limit put in place on the device to support the grids efforts? Our inverter is rated 5.5kw and coupled with a spa3000 - I’d have thought we would see 5k generation max with the restriction on the export only (via the couples unit spa3000).

I was expecting to see a max of 5kw(or near enough) to be shown on the production graphs.
You are right, most days we run at around 0.3 however with battery charging and EV charging I thought we would have the delta (upto 5kw max) being produced. Meaning I could look at electric hot water options etc, or storing more in additional batteries, or selling additional back to grid.

 

[Murdoch]

You need to address your questions in writing to the installers …

 

[karlboldy0]

Thanks - all questions sent to the installer, nothing answered in 4 days as is. Guess they will answer when they want the rest of the payment

In other news, my own testing and monitoring has reported that during very hot spells the panels are less efficient (apparently this is a legit thing) and so in recent days under the cooler weather we’ve apparently reach 4.5kwh. Will keep monitoring

 

[Bob Smith]

That's right when it is too hot the panels are less efficient.

 

[binky]

Thanks - all questions sent to the installer, nothing answered in 4 days as is. Guess they will answer when they want the rest of the payment

In other news, my own testing and monitoring has reported that during very hot spells the panels are less efficient (apparently this is a legit thing) and so in recent days under the cooler weather we’ve apparently reach 4.5kwh. Will keep monitoring

They suffer heat saturation in hot weather, fortunately we don't get much of that.