[Help/Suggestions Required] 5kW Hybrid Solar System for home

[StrikerX]

Hi,

I am looking to install a 5kW hybrid solar system in our house. I am a layman in this and don't know which brands are good and which are to be avoided etc

If someone would be so kind to guide me on this front and suggest me a setup, I shall be grateful Budget can go upto 500k+-

@rizwan400 @talhawaleed @farhan_ds and others

p.s I am in ISB/RWP

[farhan_ds]

for getting 5kw peak power you would be best installing atleast 6500W panels.. and that peak will be only for 4 5 hours max in spring and summer time when sun angles in light at max absorption level.
first you need to define what you plan top run on it, n daytime and night time. as just installing the panels themselves isnt the science alone. inverters, frames, wiring and batteries all need to be configured accordingly.

and most important, what is your max buget and what are your expectations from your system?

you can PM me instead directly to avoid mixing of information.

[danishmmh]

Please tell where you want the system to be installed so that i can suggest someone. If it is Karachi then i can refer

[gull_s_777]

As @farhan_ds mentioned,
lot of variable come into play.

I have a 3KV 24V Solar inverter installed with 16 small panels of 150W.

And this is the solar power it produces throughout the day.
(Its Solar charger is rated at max 50A, so it flats out at 50A. But panels installed are capable of putting out upto 64A in the noon. )

[gull_s_777]

Now getting a 5KV inverter possibly means you are looking at 48V setup.
But even that one will be most likely limited to 50A max solar intake. So it will generate upto 2400W max on Solar (48V x 50A = 2400W).
And 32 small panels will max it out.

My inverter specs

[gull_s_777]

Still want full 5000W from solar then gonna need an inverter in 48v which will allow upto 100 solar Amps to pass through. That'll need one hell of a cable to handle all those amps, probably 35mm or bigger.

Or simply a 96V inverter which will be fine with 16mm cable but will need 8 batteries.

[danishmmh]

Same was my plan but now i am splitting into two modules of 3000KVA each for two separate sections of the house. This will be good so that in case of faults or issue i will still have sufficient backup and power to make arrangement for replacement/repair. Plus the cost difference is significantly low for a 3KVA system x2 than one 5 KVA system

[gull_s_777]

Plus the cost difference is significantly low for a 3KVA system x2 than one 5 KVA system

How so?

Single 5KVA inverter should be cheaper than two 3KVA inverters.
You are gonna need 4 batteries with either of the setup.
48V should be more efficient compared to two 24V systems, and you'll save on the cable too.

But sure, in case of fault, you'll have a backup.

[danishmmh]

5kva requires 48v setup whereas 3kva works well with 24, cable cost is more but at the same time you also get 6 Kva load bearing capacity. 3KVA inverter is around approx 1/3 the price for 5Kva and allows spread installation of panels. If you do the sum it will be equal in cost for one 5KVa v/s 2 3Kva system with added secuity of one system failure allowing cheaper replacements.

My Idea and that is what i am currently working on.

Second advantage is being modular i will install only 3KVa in this first phase and will save on full on investment, will install a second set after a while when i am comfortable with my setup.

[syed.jahanzaib]

Sorry to interrupt, I am also planning to get 3 kva setup, a friend of mine have electronic shop in Saddar and offering 3kva (AC Volt System) hybrid solar setup for avg 100k+, is this price ok ?

1. What items we can expect to run on this 3kva solar system?
2. If I have 150 amps x 2 liquid batteries, How long 4 fans + One 17" tv + 30W led bulbs fans+led can run direct on sun then on batteries?
3. at which voltage, the inverter shifts from sun to battery , and when it will shift from batteries to KESC? Can we manually adjust the min voltage it should shift?
4. How much units saving I can expect from it? Can some one please share there experience of saving bills using solar system?

[jehanzeb101]

Well if you install 3KW panels with a 3KW inverter it cannot be for 100K. The panels alone will cost more than that. Usually sometime vendors try to confuse the customer by installing a 3KW inverter and much less panels.
I have some experience with these systems. Practically if you have 3KW panels the maximum output you ll get is 70% of that. So that will make it 2100W. The inverter is only 70% efficient (claimed efficiency is 90% or more but its complete BS, specially for chinese and Taiwanese brands). So you ll lose another 30% so you ll get 1400 Watts to the load.
More inverters are programmable so you can set lower level battery voltage at which it will switch to grid. Inverters supply power by combining battery and solar.
Realistically there wont be much savings due to the replacement cost of the batteries, plus the fact that you will never be using all the max power available from the inverter all the time.

Hope this helps.
Prof. Jehanzeb

[gull_s_777]

More inverters are programmable so you can set lower level battery voltage at which it will switch to grid. Inverters supply power by combining battery and solar. Realistically there wont be much savings due to the replacement cost of the batteries, plus the fact that you will never be using all the max power available from the inverter all the time.

Well i have a 3KV solar inverter with 16 small panels at home, and a 2KV inverter with 8 panels at work.

My two cents....

• Indeed. A good inverter will always be programmable, and by default is set to switch to grid at 23v. You can set it lower but remember at night, it will have to use wapda to top the battery up again so setting it too low might not be a very good idea.

• As for savings, still not have much idea as installation is pretty recent. And savings being nill because of batteries replacement seems a bit unfair. As you are likely to be already replacing batteries on your conventional inverter anyway.

• As for using the max output of your solar setup....
  I have all the home fans and lights hardwired to solar inverter and they run for 12h on solar and then automatically switch to grid at around 6 pm (when battery voltage hits the switch point).
  And from 9 am to 5 pm, a Desert Cooler and full size refrigerator is also running on it.

[syed.jahanzaib]

Ok my aim is to use maximum things in Solar (like all fans / tv / computer and few other items, not heavy but normal).
I really dont want the inverter to charge batteries from WAPDA(or KESC).

is there any option we can disable batteries charging from KESC.
the batteries must be charge only from solar. possible?

[gull_s_777]

Yes it is possible.
Actually i am doing the same.
I have battery charging setting set to "Solar Only", means in day time solar charges the battery and in the evening when battery hits 24v, inverter shifts to grid but doesn't charge the battery from grid.

[syed.jahanzaib]

Ok I got it.
One final query please.
As this system will be AC Volt system, is there any possibility that using same panels, I can somehow connect few small DC led bulbs + 2 DC fan? because I heard that DC fan+LED can run all night on battery as they dont take much power? is it true?
can i run DC + AC all together (using different wires or dont know )?

[gull_s_777]

Lets see....
There will be 4 ports in your Solar Hybrid Inverter.
And connections will be like this....

1. Wire coming from your solar panels
2. Grid input/supply line
3. Wire connecting inverter with Batteries
4. AC Output line supplying your home load.

As you see, no dedicated DC output option in the inverter itself.
But if you want to run some DC load too, you can connect it direct to your battery pack.

[gull_s_777]

But take care of one thing though,
you are looking for 3KVa inverter which will come in 24v flavour means it'll have 2 batteries connected.
While your DC load is likely to be 12v and you'll be taking power from one battery then, means you'll be using one battery while other battery will be standing full.
This isn't gonna be good for batteries.

For small 1KVa inverters with only one battery, no such issue.

[hkamil]

@gull_s_777 as per your calculations of 48v 5kV inverter gives (48x50=2400VA). then your system of 3kV gives (24x50=1200VA). As per your recommendations one should not go for 5kva as it doesnt give the desired output then so is the case with 3kva.
i would rather say 5kva is better than 3kva because 5kva gives outpur of 2400VA and 3kva gives output of 1200VA. The output of 5kva is double to that of 3kva.
The point is that are you sure about your calculations. Are you confident that there is no other hidden calculation involved???

[gull_s_777]

^^ this applies to simple PWM controller inverters.
You can get a MPPT controller and set the input array to 96v or even higher thus eliminating the ampere bottleneck...

[hkamil]

@gull_s_777 Sir kindly address the following:

Inverter http://inverexpower.com/wp-content/newarrivals/20170913/Axpert/AXPERT%20king.pdf
Panel http://inverexpower.com/wp-content/newarrivals/20170913/mono/310-325,72Mono.pdf

In the above link there are specifications of AXPERT KING solar inverter and inverex solar panel.. I have few questions to understand the specifications.

1) The maximum array open circuit voltage means that if i connect panels in series and add up their open circuit voltage it shouldnt be more than 145 in the case of the above inverter. Right???
If i am right in that case i should make a string of max 3 panels of 325W i.e. 46.67x330=140.01V.
2) Under the heading of Solar Charger and AC Charger Why is maximum array PV power 1500W while the inverter is 3.2kW. does it mean i sholdnt connect panels more than 1500W??? If i do so then how would i get 3.2kW?
3) Under the heading of Solar Charger and AC Charger What is MPP at Operating Voltage. Does it mean Maximum Power Voltage (Vmp) of the solar panel? What is Operating Voltage.
4) What is the Role of 24V and in case of 3.2kW if i am going to consider Maximum PV Array Open Circuit Voltage???
5) What is the difference between Maximum solar charge Current and Maximum AC charge current and their importance in designing the whole system
These are quite lengthy queries and would consume a lot of your time. I would really appreciate you to explain to the best of your knowledge.