DIY... am I crazy?

[sanch3z]

5 minutes ago, PhilT said:

regarding compatibility of SE optimisers with other inverters, they say:-

"Benefits of the SolarEdge P370i universal optimizer
Stand-alone optimization technology (IndOP™) - allows operation with any inverter and does not require any additional interface hardware"

they have a special setting reserved for use with their own gear. You can disable this if you want to use it with other inverters by all accounts

[markocosic]

Those universals I'd not seen before and it indeed looks like id you can live with the reduced capacity (10A vs 15A) they're indeed usable with non solaredge inverters after you get up on the roof and set them all back to non solaredge mode. Still a switching cost there.

 

I'd still buy the tigo units that can handle more power and work with everything out of the box with no setup and at a lower price point though.

[Dillsue]

6 hours ago, JohnMo said:

But 3.6 kW inverter will have a small tolerance for over locking possibly a few 100W not a couple of kW.  Then if you want 5.6kW you get into an a correctly sized inverter, but with export throttling. Or you go G99.

I dont know about other manufacturers,  but SE allow several kw of DC input over the inverters rating.  A G98 SE3680H is rated at 3.68kw but can have up to 5.7kw panel input connected. If the array is split and facing differing directions you can have more connected so long as total generation at any one time is less than 5.7kw.

[sanch3z]

16 hours ago, Dillsue said:

I dont know about other manufacturers,  but SE allow several kw of DC input over the inverters rating.  A G98 SE3680H is rated at 3.68kw but can have up to 5.7kw panel input connected. If the array is split and facing differing directions you can have more connected so long as total generation at any one time is less than 5.7kw.

 

if your panels draw the 5.7kw and are connected to a G98 rated 3.68kw inverter, what's happens to the surplus 1.2kw? is it used, or effectively ignored? I understand that a 6kw array is unlikely to pull the full 100%, more like 4.8-5kw so it makes sense to have more panels to account for the loss

[Dillsue]

7 minutes ago, sanch3z said:

 

if your panels draw the 5.7kw and are connected to a G98 rated 3.68kw inverter, what's happens to the surplus 1.2kw? is it used, or effectively ignored? I understand that a 6kw array is unlikely to pull the full 100%, more like 4.8-5kw so it makes sense to have more panels to account for the 

 Your 5.7 kw of panels will only generate at that level for that small proportion of the year and anything generated over what the inverter can output doesnt get processed and is "wasted", during that shortish period of the year and for a few hours each day during peak generation. Early and late on peak summer days your oversized array will generate earlier and later in the day giving a longer spread of useful power but the generation peak will be "wasted"

 

PVGIS gives hourly predictions so you can input your details and see how much any particular size of array will generate. I think you may need Excel to make sense of the data!!

 

[Nickfromwales]

On 05/09/2022 at 10:57, sanch3z said:

I think the reason that kit is pitched at 'off-grid' (not that I want that), is because it's mostly aimed at people with Caravans, or small workshops

Not really. It will be very specific the the inverter being ( or not being ) able to be AC / grid connected. It’s to do with synchronising the 50hz together, so a grid capable inverter will use the grid 50hz like a metronome to harmonise both bits of ‘equipment’. 
It’s why the parallel capable inverters need a cat5 umbilical, unit to unit, so they can all align to the grid frequency. That and other info. 

[sanch3z]

1 hour ago, Nickfromwales said:

Not really. It will be very specific the the inverter being ( or not being ) able to be AC / grid connected. It’s to do with synchronising the 50hz together, so a grid capable inverter will use the grid 50hz like a metronome to harmonise both bits of ‘equipment’. 
It’s why the parallel capable inverters need a cat5 umbilical, unit to unit, so they can all align to the grid frequency. That and other info. 

ok, that's my lack of knowledge shinning through again... get used to it 😉

[Nickfromwales]

1 hour ago, sanch3z said:

ok, that's my lack of knowledge shinning through again... get used to it 😉

Lol. We’re both getting an education here, I assure you