DIY Solar setup 36kw

[pwuser15979933135]

Hello Pakwheelers, we are planning to install 36 KW solar panel setup at a remote location (a factory) near Thatta city as a DIY. The building where we are installing this setup has mostly load of ACs and computers. The total load of the building is 55kwh in summer daytime. So we are planning to install 72kwh solar setup to cater electrical needs of the building during daytime. During night time we will be on WAPDA.
Initially, in the first phase we will install one 36 kw inverter with 96 solar panels of 445 watt each. we have chosen Huawei 36 KTL invertor along with JA solar panels mono perc 445watts, the procurement is in process and hopefully we will receive panels, inverter and related accessories within 10 days from now. Solar panel stands are in process of fabrication at our plant workshop which we are making with 40 x 40 mm angle iron. I have a team of skilled electricians, electronic technicians, mechanical fabricators and civil teams at my disposal but they need guidance at every step as they also dont know how to make connections of panels with inverter and how to connect inverter with building transformer/circuit breaker etc.. I have following questions,

1. We are installing 96 solar panels of 445 watt each, so how many solar panels should be connected in series. In market they are saying to make series of 16 panels, in that scenario we have to make 6 strings of 16 panels each and each string will be connected to inverter individually. Is that correct?

2. Our plant has a grid station of 132 kv and we also have a power plant from where we sell electricity to WAPDA. At grid station we have 20MW, 132/6kv transformer from where that 6 kv is transmitted to different area transformers of 6kv/400v. The building where we are installing this setup has a transformer whose input is 400 v, 3 phase and output is 110-0-110. Through out the building 2 phases were joined together to make 220 volts and ZERO is used as neutral. So where the inverter output will be connected. Do we have to connect the inverter output to the primary side of transformer.

Pakwheels gurus are requested to kindly guide me regarding selection of equipment and further guidance will be required in every stage of project.

Regards,

[xzap042]

Bro, a sincere suggestions would be to consult any professional for this job. This kind of project shouldn't be a DIY unless you have prior experience of such scale.

I have a team of skilled electricians, electronic technicians, mechanical fabricators and civil teams at my disposal but they need guidance at every step as they also dont know how to make connections of panels with inverter and how to connect inverter with building transformer/circuit breaker etc.

Am sorry to say but the way you put it, do them a favor and not put their life at risk if those skilled works still need guidance.

[capsat]

in the point 1 there are several loop holes, an amature can sort out those nick nacks with plain basic knowledge of series and parallel. Voltage and Current play crucial role incase of alternate energy DC conversion to AC voltage.

for your convenience guidance and understanding check the 2 images below

i have read your post, and picked point 1 to start with.

as power producer you should be having designer & consulting engineers at your payroll. Which i assume is not available. in case there is an issue to consult the existing consultants, however you have resources available. The task shall not be handled by amatures, as it has DC voltage & DC current involved.

There is an engineering consultant who can help you against a fee of Rs.250,000.00. (quarter of a million Pak Rupees). He is member of Pakistan Engineering Counsel and NEPRA approved designing specialist of Alternate energy sources. Solar & Wind Power both.

scope of consultancy will cover system designing, equipment lay out, list of material required for connectivity to load and equipment protection. The gentleman will be available for system installation supervision., only after a time line is provided by you. If you are interested please email to capsat@outlook.com

[pwuser15979933135]

Huawei SUN2000-36KTL.pdf (272.8 KB)
Thanks for your kind feedback @capsat, Our plant management wants us to install this setup by our own resources and consultation can only be taken from net and/or from equipment suppliers. The installation is not very complex but definitely there are many questions in our mind which needs to be answered.That is the reason I posted here.

The main concern is regarding making of series strings, how many panels to be connected in series. The attached manual says INPUT can be upto 1000vdc. An individual panel provides around 38vdc at noon. so 16 panels should make around 600 vdc. If we see the inverter manual it shows two banks for solar inputs and each bank has 8 inputs (4 for positive, 4 for negative) means we can connect a total of 8 strings.

Can anyone guide me regarding connection of solar panels to Huawei inverter.

[nfssaad]

you plant management appears to be a typical seth .... spending corore on equipment but not pennies on proper design consultant...

this system HAS to be net metered. you will be running normal split AC instead of inverters, which will have massive surge loads on the inverter.

simply use the inverter to pump electricity to the grid. do not pass any load through this inverter.

the units consumed by your equipment will be offset by the units produced by the inverter/solar setup.

[pwuser15979933135]

Hello nfssaad,
Yes i am employee of typical mindset seths, they want maximum savings in any plant project. However this project is just to trained me and my team to get themselves prepare for a 8MWH solar project for plant.

Our system is already net metered, as i stated earlier we are selling electricity to wapda. I will soon post electrical drawing of our grid station, power plant setup and HESCO grid setup.

With your statement "simply use the inverter to pump electricity to the grid" I understand that we should connect the inverter output to primary side of building transformer (400 VAC) which is coming from Grid Station 400 Volt bus bar.

[capsat]

Playing with DC CURRENT is way too risky, ask your seths for life insurance coverage before any such plug n play attempt
Please exercise caution

[malik.com1]

Hi Brother
Been a while you posted, still waiting for your update. Any experiences you share will help the community at large.

My personal experience with Grid-tie systems is that a significant percentage of the units every month are being lost because IESCO is always doing their "repair and maintenance" between 9am - 2pm.

The solar sales man will never tell you that their projected ROI does not factor in the power outages. In my experience you should add 2 years to their claim. For example they tell you the system will break even in 5 years, it is actually 7.

Main problem is that when the system is producing 8 or 10 kilowatts and grid is down, your home load is 1kilowatt the rest of the power is lost, usually batteries are already fully charged.

Why don't wapda (or specific utility provider in your area) give you guaranteed benefit like the famous IPP contracts, that even when the grid is down, your net meter system will be counting to your advantage?

[pwuser15979933135]

Yes brother, grid tied systems has a disadvantage that we you loose grid the solar inverter stop producing electricity. However at our location we are not dependent on WAPDA as we have our own power plant which remained operative round the clock.

Alhamdolillah, till yet we have installed and operate one 36 kw setup, one 60kw setup and currently we are working on 100kw solar setup and another 300kw solar setup is in pipeline. We are using Huawei solar inverters which are string type inverters and can be install outdoors as their protection level is IP65.

36kw setup having 96 solar panels.

60 kw setup having 156 solar panels

Ongoing 100kw setup with 65 panels out of 260 panels