DNO G98 3.68kW export limit - inverter choice

[rabnudj]

Hi, Following on from my previous post I have another question that I'm struggling with. It might be best to start with explaining what I want my system to do as a background to my inverter question. I want my 4kw panels feeding into a hybrid inverter that charges a decent sized battery(14kwa) and exports as little as possible. I'd like the batteries/solar via the inverter to be able to support 5kw of power load.

This will mean that inverter will have enough power to deliver over the 3.68KW G98 limit, I understand that many inverters self limit by monitoring the export.

So my 1st question...

When an inverter is rated 5kw what does this refer to exactly ?
* power conversion from solar to battery
* Power conversion from solar to AC
* Power conversion from battery to AC
Or does it refer to all three or combination?

My 2nd question...
If a 5kw inverter (over G98 limit) self limits export to bellow 3.68KW is this G98 compliant ?

and lastly, any general comments about hybrid inverter choice would be most welcome


TIA

James

 

[johnb2713]

Hi, Following on from my previous post I have another question that I'm struggling with. It might be best to start with explaining what I want my system to do as a background to my inverter question. I want my 4kw panels feeding into a hybrid inverter that charges a decent sized battery(14kwa) and exports as little as possible. I'd like the batteries/solar via the inverter to be able to support 5kw of power load.

This will mean that inverter will have enough power to deliver over the 3.68KW G98 limit, I understand that many inverters self limit by monitoring the export.

So my 1st question...

When an inverter is rated 5kw what does this refer to exactly ?
* power conversion from solar to battery
* Power conversion from solar to AC
* Power conversion from battery to AC
Or does it refer to all three or combination?

My 2nd question...
If a 5kw inverter (over G98 limit) self limits export to bellow 3.68KW is this G98 compliant ?

and lastly, any general comments about hybrid inverter choice would be most welcome


TIA

James

I think if the inverters are on the approved list of the DNO's they will accept the export being turned down / off. Be very careful in your choice of inverter, many of the cant do the full output when running on batteries (seems mad to me but thats what I discovered). Growatt SPH6000 has an output of 6kW but on batteries 3 kW for example. Victron Multiplus II that ive just added to my system has a rated output of 5kW but peak (even on batteries) of 9kW. Victorn do have some very nice if somewhat heavy duty equipment, have a look there.

 

[rabnudj]

Thanks,

Checking if an inverter is G98 certified is an obvious detail to check for.

I'd enjoy very much building my system out of Victron components, unfortunately I'm not that flushed! Also the whole point of this, is to get to that break even point asap, victron purchases will only delay that. (IMHO)

 

[johnb2713]

I'd enjoy very much building my system out of Victron components, unfortunately I'm not that flushed! Also the whole point of this, is to get to that break even point asap, victron purchases will only delay that. (IMHO)

They do seem to be at the upper end of the market BUT they also seem to perform better than their published specification. The large performance margins will help with your break even figures compared to lesser inverters. I personally wouldn't hesitate if the requirement came again.

 

[MHarv]

G98 and G99 Type Tested Inverters on ENA Register, will help you fill in the relevant documentation, <16A
for greater than >16 but less than 32A for larger inverter capacity G99 Fast track limited to 3.68kw export with
G100 device or Full G99
Speak first to your DNO

 

[bladerunnerpv]

ENA is here
https://www.ena-eng.org/gen-ttr/index?Action=Home

 

[bladerunnerpv]

When an inverter is rated 5kw what does this refer to exactly ?
* power conversion from solar to battery
* Power conversion from solar to AC
* Power conversion from battery to AC
Or does it refer to all three or combination?

James

I think it's usually the nominal AC power output to the grid, usually under "output AC" on the datasheet. Others will likely know better than me.