Extra Solar power, back to grid?

[Hansa]

Hi there 

This is currently what's happening with our system. 

 

Seems like there's so much potential that could be used more profitably. 

Once the batteries are charged up it seems the solar energy isn't being fully harnessed. 

Obviously the load will increase when we move into the building, but since it's a small business there won't be ovens etc drawing huge loads continuously so there should still be more than enough to feed back into the grid. 

 

3 x kodak max 7.2kw inverters. 

4 x shoto SDA10 48100 5.12kwh

Would feeding excess power into the grid be possible with these inverters? 

Edited September 10, 2021 by Hansa

[Coulomb]

7 hours ago, Hansa said:

Would feeding excess power into the grid be possible with these inverters?

I don't believe so.

[Sc00bs]

My understanding is that they are Off Grid inverters, they will replace the grid when they are able and then switch power back to the grid when they are not able to supply enough power. 

They are not able to "blend" the power between grid & solar, it is either one or the other.

[Coulomb]

12 hours ago, Sc00bs said:

They are not able to "blend" the power between grid & solar,

The Axpert MAX used by the OP, and other Voltronic Power models with high voltage Solar Charge Controllers, actually do this blending in SUB output priority mode. But they limit the amount of power pushed through from solar to that used by the grid and battery charging, so that none goes back into the AC-in port. Apart from occasional blips from imperfect control, which can be a problem for certain types of utility meter.

[Sc00bs]

Thanks @Coulomb, so they are able to blend loads between grid/solar/battery?

[Coulomb]

14 hours ago, Sc00bs said:

so they are able to blend loads between grid/solar/battery?

Yes. But only the ones with the high voltage Solar Charge Controllers. Which is the majority of the models now (sadly, in my opinion). That certainly seems to be where the industry is going (high voltage strings).

And only in SUB output priority (often called "mode"), as far as I know, but they can do it.

[BritishRacingGreen]

On 2021/09/11 at 4:44 AM, Coulomb said:

But they limit the amount of power pushed through from solar to that used by the grid and battery charging, so that none goes back into the AC-in port.

That will nicely explain the reason why the grid always mixes in some power to the output , even though the solar has  enough energy to supply all of it.  Which I have proven often by removing grid , and then solar ramps up to supply everything the output demands.

[BritishRacingGreen]

2 hours ago, Coulomb said:

sadly, in my opinion)

Why you state that ?  

[Hansa]

Seems we'll just have to use the SBU option with solar assistant controlling things. It cuts off grid completely in this mode it seems from the graphs 

[Hansa]

On 2021/09/10 at 2:49 PM, Coulomb said:

I don't believe so.

Thanks 

 

That's unfortunate though. So much potential 

[Coulomb]

18 hours ago, dropkick said:

Why you state that ?  

I don't like the high voltage SCC models because they don't include insulation monitoring and are therefore unsafe. And therefore illegal to use in Australia, though I'm sure that there are plenty installed here.

You also get less total charging current, in the admittedly rare case of combined utility and solar charging.

There is also the hassle of leakage when panels are wet, sometimes triggering bus over-voltage errors and other problems. 

Plus the whole idea of half wave rectified AC superimposed on high voltage DC seems crude to me. But that's just subjective; most transformerless grid tie inverters are the same. 

[BritishRacingGreen]

On 2021/09/13 at 1:39 AM, Coulomb said:

I don't like the high voltage SCC models because they don't include insulation monitoring and are therefore unsafe. And therefore illegal to use in Australia, though I'm sure that there are plenty installed here.

You also get less total charging current, in the admittedly rare case of combined utility and solar charging.

There is also the hassle of leakage when panels are wet, sometimes triggering bus over-voltage errors and other problems. 

Plus the whole idea of half wave rectified AC superimposed on high voltage DC seems crude to me. But that's just subjective; most transformerless grid tie inverters are the same. 

Yes I tend to agree, let's be honest high voltage bears plenty disadvantages  , only advantage is really is where you need to save copper / current / heat ( I think somewhere along the line industry will have to double up on that 48v batt voltage in lieu of consumers ever hungry increasing storage requirements. I hate it when a current of more than 50 amps is drawn)

Edited September 14, 2021 by dropkick

[Jacques Ester]

On 2021/09/12 at 4:59 AM, Coulomb said:

Yes. But only the ones with the high voltage Solar Charge Controllers. Which is the majority of the models now (sadly, in my opinion). That certainly seems to be where the industry is going (high voltage strings).

And only in SUB output priority (often called "mode"), as far as I know, but they can do it.

They King is also able to blend.

Only has a 150VDC MPPT

[Coulomb]

6 hours ago, Jacques Ester said:

The King is also able to blend.

Only has a 150VDC MPPT

145 V, absolute max.

Actually, there is an Axpert King II model about, with 450 V or 500 V absolute max PV voltage. I've not seen any, nor any firmware for them.

[granerod]

Sunlight hits solar panels which are essentially silicon cells encapsulated in glass and an aluminium frame. Cells produce direct current – DC.