Solar system for Office.

[Stonemason]

That thing doesn't make sense, battery is supplying 67w but the house is using 66w? What is UPS?

UPS is the essentials and the house is the non-essentials. When Eskom is off, the essentials gets power from the batteries or the PV and the non-essentials are off.

 

[Crusader]

On Deye inverters they did an update where the trickle feed from the grid now seems to be around 100W regardless of what your setting is (ours is set at 20W). The inverter seems to take between 90W - 120W from my observation.

 

[Lupus]

On Deye inverters they did an update where the trickle feed from the grid now seems to be around 100W regardless of what your setting is (ours is set at 20W). The inverter seems to take between 90W - 120W from my observation.

So that possibly went to Sunsky as well, but that does seem high

 

[leon.davibe]

Right so Assume I don't know what you all know about this stuff.

Do I connect the solar panels in parallel or series? I have provided a link to the inverter below.

Sacolar - WiFi compatible- 5KVA / 5KW Pure Sine Wave Axpert Type 48V Inverter / 100A High Voltage MPPT / Parallel

Other inverter recommendations are welcomed but I was told these are not bad.

on the high voltage you put panels in series , you just have to heed the limits
ie some say never exceed 80% of max voc

this is a high voltage so series
and then you may start running 2 parralel strings if the voltage come to close to the max voc
if going parralel just make sure to fuse the seperate strings if failure on one the other parralel string may set it on fire

to get going you need panel count to get you high enough voltage to get a decent bit past the startup voltage of mppt to get some decent production
ie you would need at least 5 panels to get going if 41v ish 60/120-half-cut panel or 4 if using 50v ish 72/144half-cut panels

 

[leon.davibe]

My computer consumption :300watt/h from the plug. I need to be able to work for 14 hours a day minimum.

Other considerations is my Fibre that consumes 32watt/h hour for the ONT and Router along with 2 router UPS systems.

Total office consumption is 332watt/h.

Solar backup system will be
1X 5.5Kw/h Lithium Battery
1X 5Kw Inverter
4X 540 Watt solar panels.

My math so far is 5500watt/h - 20% (5500 - 1100) = 4400watt/h
Total power consumption is 332watt/h
Total Time 4400 / 332 = 13.2 hours leaving a 20% charge on the battery. (Excluding solar power generation.)

Will this work? What am I missing?

Yes the panels will carry the load and battery will be backup in really crap weather and for the kettle etc

The panels will probably be able to carry the load even on bad weather days

I assume the panels are 72/144 cell 50v ish if that is the case it is fine

Just don't buy 60/120 lower cell count panels otherwise you will have to buy at least 5

On most (not all) 5kw inverters with a high voltage mppt the startup voltage is 120v

I found that the 41.3v panels working voltage is to close to the 120v and production suffers

ie i got 1.5 times the production from 5 vs 4 panels not 1.2x as expected

I only had the 2275w panels for a short period (aug/sept), live in western cape normally lower avg output vs other parts of SA

The panels produced on avg 8kwh per day
Best day 13.62kwh
Worst rainy day 1.26kwh

That time of year, summer will be more ie i now have 3650wp
1.6times what i had then and my avg for january was 17.96kwh per day
worst day 4.99kwh (0.62kwh per 455w panel)
Best day 26.87kwh (3.35kwh per 455w panel)

with 2275w array
worst day