Sizing Inverters & Chrage Controllers??

[rurokenshi]

Hi,
I have a question regarding charge controllers and inverters.

I want to size a charge controller and inverter for a 65kWp system
The modules used are 34v,165Wp
and my specification is for a max of 1000v string system


What would be my charge controller and inverter specs?

i am using 2v,1500Ah batteries for 4 hours backup (roughly 200 Nos)

I am a newb when it comes to solar...i am slowly learning..so pls hlep

Regards,
Ruroken

[Mike90250]

Questions
What's KWp
Whats Nos

[rurokenshi]

kWp - kilo watt peak
Nos - Number (Not Nitrous Oxide!!)

Not so obvious uh...

[Mike90250]

Well, you are speaking in non-standard terms. Also forgot to ask, what is the battery bank voltage?

1,000V dc solar string voltage ? YIKES.

There are no High voltage string controllers for batteries that I know of.

Pure grid tie inverters can run up to 550VDC from the panels.

Battery based systems can run up to 48V DC batteries, and about 140VDC on the string.
(some industrial systems can go to 300VDC, but they have interlocks on the doors to the battery room)

Systems aren't rated as 65 KWp, they would be listed more like 30KW or 5KW. Any install over 10KW would need special utility permission, as they are not prepared to deal with that about of back feed power. And over 10KW may need to be a 3 phase system.
Example

[rurokenshi]

Thanks for the info mike...the system used here is a grid tied system.
Special permissions have been obtained...it is a govt project....

I have a few questions though:

How would the solar string be sized?...according to inverter voltage or is it the other way arnd?...size the string first and then select the inverter??

If this is an off-grid setup...how would you size the batteries?

Thanks

[Mike90250]

How would the solar string be sized?...according to inverter voltage or is it the other way arnd?...size the string first and then select the inverter??

If this is an off-grid setup...how would you size the batteries?

To size the strings, you select your inverter, and the inverter spec will tell you how the strings should be configured. You will likely have several inverters, and depending on the capacity of each one, will determine how many you will need. As a matter of principal, I'd not go past 80% of an inverters capacity. If it's an 15KW inverter, I'd only feed it 12KW of PV (80%)

Battery sizing, will the batteries be for daily cycle use, or standby if the power fails?

[rurokenshi]

Thanks Mike.....the battery is used for standby purposes only...

battery power is fed only when both solar as well as the grid fail (like in the night..when there's no solar and there are power cuts!!)


I have another question though.....Can we size the inverter with only the Watt Peak of the solar panel like if its an instantaneous power of 175W from a sharp panel, can we size the inverter based on this...or do we size the inverter after getting the load pattern....because most of the inquiries laid out are sizing inverters given the instantaneous power of the panel!!!...

[Mike90250]

size the inverter to the loads you expect it to drive.