earthrealm:

imagine driving to lagos from abuja on a 2cylinder , 4 cylinder and 8 cylinder car, while each car can make the trip, over time, the 2 cylinder car will likely breakdown first, while the 8 cylinder will serve u many many yrs...same goes for batt n inverter system,s

mmh, on 2nd thought, the comparison with engine cylinders is not so bad when you take the batteries in parallel?! i.e. more cylinders = more battery banks (= lower Amps per battery bank.)
Because what I often see in the forum is a misfit between size of inverter and battery capacity & "architecture" (=parallel x series). And of course it depends on the type of batteries.
Here is one more analogy: the inverter is the engine; and the battery is the drive gear. Often a bigger engine is chosen than the drive gear can withstand... and the drive gear breaks faster than expected.
mmh, does this make sense?

I think it is legitimate, that various installers follow different "philosophies" when sizing and choosing the components. Experience will tell what set-up is best for the client's application ... Obviously homeowners/DIY users have different demands than business clients.

@olumz1
Thanks for this thread! I am following...

Here are some general thoughts.

The advantages buying from my fellow solar installers/retailers:

1) Make sure you buy from a serious vendor who is able to provide you 12 - 24 months of warranty/guarantee.
If something goes wrong, they will be happy to fix it, because their reputation is on the table.
(normally 2 years for workmanship; 10 years manufacturer's material warranty/guarantee and 20 years of performance warranty/guarantee - if the manufacturer doesn't go bankrupt!)

2) It would be great to build a sustainable two-tier solar trade industry in Nairaland. Do-it-yourself is good, but on the other hand you should trust the expertise and the know-how of your solar installer of choice. You find many gurus here in the house. (Two-tier: importer/wholesale -> installer/retail vendor.)

3) This forum is good to 'inform' potential customers. So you are prepared to ask the right questions and to have a good idea what size/capacity you need, and what budget is required. The professional solar installers know what fuses, breakers, surge protection devices and cable sizing is required, so that you neither burn your fingers nor your house - in case of lightning!

Eventually, gurus here are happy to provide free, valuable consulting in order to promote solar energy.

sunny regards,

BlackBaron:
Hi guys
I wanted to find out if this is a good one off offer from a private individual overseas...

250W x 4 solar panels
4000KW inverter

Equivalent amount is #400,000

Please, NOTE...Asking only for my own purchase. Not a seller or whatnot.

Good evening @BlackBaron,

would you like to tell the house what brand of solar panels you may get? I am just curious.

earthrealm:
@ILOVETHESUN, THE PART U SAID A SINGLE STRING HAVING UPTO 1000v depending on your inverter?...i find it a lil strange, yet to see an inverter or CC that can accept 1000v, kindly shed more light on this

Sure,
1000 V is open circuit by the way, so maybe 800 V Umpp hits the inverter. (By the way, you can burn your fingers when not properly isolated )
You can connect grid-tie solar inverters, e.g. SMA SunnyBoy, to SMA Sunny Island on the AC side. SMA Sunny Island is the charge controller for a 48 V battery bank. During sunny days you get AC from the solar inverter, that can be used directly/immediately by your AC loads. The surplus is stored in the battery. The advantage for big solar installations, like mini-grid or three-phase: there is no conversion and therefore less loss from converting high-voltage DC from the solar panels to 24/48 V battery bank "bus" and then from DC to AC.

In general, for loads < 4.6 kVA, DC bus "architecture" is prefered.

(And regarding solar parks there are even central inverters that support upto 1500 V DC and convert to 460 V AC to connect to MV transformator... just saying to complete the picture!)

earthrealm:



Errm, i beg to differ, ur statement is general and sweeping, there is what is called cable sizing in solar systems [you shud know this na].

for example i have a 1kw panel feeding a 24v inverter, i may be fine with #10awg/7mm is rated for 15amps x 2 for distances shorter than 25ft or so...if longer the losses will exceed 5% which implies power losses upto 100w n rising depending on th e distance, so assuming same setup the owner increases his panles to 2000w wch is about the max 80amp mppt CC can handle for a 24v setup, thus this wud imply 2strings of 4panels each or 3 x 3 config, so as not to exceed the 150v rating of most CC's, thus you are looking at 2000w/120v or 2000/90 wch ends up giving you about 22amps, and thus ur losses if you are using #10awg cables might rise to 10% or more if your distance is more than 25ft.

the optimum design is to keep losses under 5%, thus shorter distance btw panels and CC is always recommended

Good morning,
I think you misunderstood me?
Just for clarification I think you have a different wiring scheme in mind than me?! I am referring to the wiring of a single string between the solar panels on the roof and the connection point. (Let's take a standard solar panel with 8 Amps (Imp)). A single string can have up to 1000 Volt (Uoc) depending on the inverter. And if you have multiple strings, then I have multiple pair of solar cables coming from the roof. I would suggest to connect them in a combiner box with fuses. The wiring between the combiner box and the solar inverter is a different story, which you described.
Cable sizing is a must for safety, I agree. My threshold of 1% loss is my personal preference, that's why I call it rule of thumb without calculating.
(And if you have higher voltage entering into an MPPT solar inverter, your MPPT starts working sooner in cloudy weather as well. If you can afford it and invest more in copper, you will get more juice at the end of the pipe.)

This looks like a shielded audio (stereo) cable. 'max 600 Volts'
Solar cables state 'max 1000 Volts'.

@DuraCon

May I ask why the farm is being sold? [question is answered]

Reason for selling: owner relocating abroad

Would you like to upload some pictures?
How many people are required to operate this size of farm?
(Sorry, I am not a poultry farmer but a private investor.)

Thanks!

azz19:
Pls how can I get the latest price of foreign inverters and batteries

Hello @azz19,

let us please know what you need?!

earthrealm:

...2ndly am yet to see any solar cable bigger than 10awg/7mm, so @house do u guys simply use normal/house wiring 10mm or 16mm cables?. if yes, how is it holding up to the elements/weather etc, or u put it in pipes?

Solar cables are double insulated with UV resistant PVC. 4 mm2 for length shorter than 25-30 mtr. (it's my own rule of thumb the resistance should be as low as possible, e.g. power loss < 1%); 6 mm2 for longer distances; 10 mm2 are found rather in large solar parks with central inverter. For Solar DC on residential houses 4 and 6 mm2 should do. I wouldn't recommend normal cables. UV resistant PVC pipes are not cheap in my opinion. I have a picture of a commercial installation. The pipe is 5 years old... with many cracks...

Barezzi:
Lovely! We're getting there...

Take a look at the link below,it's a very comprehensive analysis of renewable energy in Nigeria.
Very interesting read...
https://www.giz.de/en/downloads/giz2015-en-nigerian-energy-sector.pdf

Thanks for the link! It is a valuable study.

Gennextech:
NIgerias largest solar powered filling station PETROCAM IN AJAH LAGOS STATE ppowered by Gennex technologies (93.84kwp)

Great!
So the oil industry admits that solar power is more efficient, cheaper in the long run and cleaner than burning oil and gas to generate electricity.
(For your information the French oil company Total bought SunPower some years ago in order to build Solar power parks/plants and to become an independant electricity provider.)

Barezzi:

Where did you get this info from?
I understand when selecting deep cycle batteries, focus should be on the C20 rate. A C24 rate would've been perfect!
If i discharge a battery at C20 rate and recharge it at C10, is that a full cycle? Is this cycle
a function of the charge/discharge rate? I'm curious as to how you arrived at the C5 full day cycle dogma.
I have been thinking, should battery banks be sized for whole day or night time use?

Dear @Barezzi,
maybe there is a misunderstanding?!
I agree that you should discharge at C20 rate. But what I wrote is my observation that people think they do discharge at C10 rate, but in the evening they draw more power so it is rather a discharge at C5 rate. It is not a dogma! And it is not what I'd recommend.

What I recommend is not to stress your batteries by not discharging below DoD of 75% within 5 hours.

For clarification: yes, I call it a full cycle when discharging to DoD x% and then charging again.

battleaxe:
May I ask how you arrived at 1,000w solar panels, sufficient to charge the 9600Wh battery bank?
(Note taken of the other factors added on top of the 1,000w)

Hello @battelaxe,

if you want to charge from 0 Wh to 9600 Wh, you're right. It is "difficult"/not possible during a single day. If you have cloudy days then you will need more solar panels anyway.

I suggest DoD of 50% or better DoD of 60%. Then 1000 Watts should be OK to charge the battery with 4800 Wh or 3840 Wh during the day with 5 - 6 hours of sun. Do you agree?
I'd rather size the max according to the battery capacity, in order not to stress them. I'd get rid of the old battery bank and get two banks with four 12 V each.
If you increase the number of battery banks (in parallel), then you can increase the total Amps of the system, e.g. 2 x 20 Amps if you have 200 Ah batteries. That's why I stated 5 kVA is a lot and should be operated with current limitation.

What I observe, people do their sizing according to their finances - what is obvious - but they end up replacing their batteries within a year or two. People take a single day as the duration for a full cycle. In fact it's rather C5 (=5 hours) discharging to DoD 50% within 5 hours after charging. But I'd recommend to go DoD 75% within 5 hours. This will almost double the life of a battery.

@Dishtech:

Good morning,

good choice to go solar!

I do not have a good feeling about your current setup: 5 kVA inverter plus 4 x 200 Ah in series (48 Volt).
It is not a perfect match. Your batteries will suffer if you draw more than 20 Amps (approx. 1000 Watts).
And I assume that you charge them too fast as well and they get hot. You should limit the current otherwise your batteries won't last long.
(5000 / 48 = approx. 100 Amps!)

Here is my calculation:
1000 Watts to charge the existing batteries
plus
200 Watts for ongoing load (not all of the 415 Watts loads will be on simultaneously during the day?!)
Total 1200 Watts required x 1.2 or 1.3 (factor for losses and inefficiencies) = about 1.400 - 1.600 Watts(peak) on the roof.

My advice: how about a more energy-efficient TV and bigger battery bank as well.

bigrovar:
Brothers. I need help/suppliers/suggestions for a 15KVA / 20 KVA inverter system. It is required for a High Performance computer setup that requires pick load of 9900Watt of power. This is meant for highly rated computational science research. High end (US, Europe ) product will be considered.

Hello,

I have two General Electric 15 kVA ProSite UPS available - without batteries, but with a rack.
It was in use only for a couple of weeks.

It is possible to put them in parallel, so it is an N+1 fail-safe configuration.
Manual/documentation available.

Interested?
Send me an email.

sunny regards,

@MisterKings

Can you please let us know how much and what solar panels are on the market?! Because I am curious what brands are available. Thanks.

Oh, and profit in the report is too high. Solarcity is basically a financial leasing company. They grew and grew in order to go public. When going public there were many questions about their accounting books how to value all those solar systems in the books. So the fresh money could fill the holes

@earthrealm

Sorry, but Sunpower back-contact cells and Panasonic joint HIT cells are in a different category than mono.
And poly are not bad per se. Sunpower and Panasonic are the Mercedes. BenQ panels have Sunpower cells incorporated. BenQ offers 335 Watts(peak) panels! That would be my dream panel. If you can only afford a 200 Watts panel? Then you choose a poly from a brand.

And it really depends on the size of the system (string size, V oc of Sunpower is higher) and the available roof space.
And the size of the frames are different as well, e.g. six Sunpower panels don't fit on a standard 6m alloy rail. You can put 5 and then you need to cut.

In general I do agree with you, but please take into consideration that the cost of BOS including workforce is referred to the US. (I have not read the report, though) i.e. in a high cost labor market (US, Northern Europe > 20 USD per hour) then BOS is high as indicated.

Sunpower is often used in conjunction with solar trackers where surface is limited.

But in Nigeria cost of BOS is be much less, so the total cost of poly per Watt is cheaper.

The report is for rich countries.

In terms of quality, I'd rather recommend to choose a brand where you will get warranty in the next 10 years from the manufacturer.

(By the way if I can afford, I choose glass/glass panels from Solarworld as well. They are more durable than panels made of glass/back-sheet foil. But it is tough to get any.)

I think I would be able to build a 100 kWp roof-top system with Korean or Japanese brand panels and European inverters for 1.7 USD per Watts(peak).
a 100 kWp with German brand panels for 1.8 USD per Watts(peak)?! And with Chinese panels for 1.5 - 1.6 USD per Watts(peak)?!

The smaller the system, the higher the specific cost per Watts(peak).

My next topic:
How much is electricity from a solar system?
...

Obimind1:
Good day @ everyone in the house. I have 2*200ah battery on a 24v set up 1.4va inverter, which I have used for over 2years now. I'm planning on adding 2 more 200ah battery so that I can have a longer back up time. The present batteries are not doing bad presently but I'm scared of adding 2 more batteries to avoid one battery bank acting as a load on the other. How can I achieve this dream of having a longer back up time without having more problems at the end of the day? Ur suggestions are highly welcome.

You already know the answer and the reason why.
So, sell your old pair, and buy four new ones.
(There is a technical solution to the above problem: it's called Battery Balancer. But I will not discuss it here, because it is not cheap >300 USD and you need some good understanding how to wire it correctly.)

But honestly, if you have space on and access to your roof, I'd recommend that you invest your money in a solar panel and a solar charge controller. They will last longer than your lead-acid batteries. Good quality will last up to 25 years. Get a 20 or 30 Amps solar charge controller, and buy a single solar panel, later you can get a second one and then increase your battery capacity.

sunny regards,

Haha Gennextech,

so now I owe you a box of beer?

sunny regards,

Here is one more scenario: No.3

Cloudy weather and no light:
Solar production (1 kW) < Load (2 kW)
-------------------------------------
Battery bank will provide 1 kW, until Low Voltage alarm kicks in and the genset is started.

(I have added the grounding.)

Scenario 2: Sunshine

Solar production (2 kW) > Load (1 kW)
------------------------------------------
The rest (1 kW) is put into the battery bank

That's the reason why I prefer programmable inverters.

Scenario 1: Sunshine
Solar production: 2 kW
Load: 3 kW
---------------
Grid: 1 kW (if available)
(If light is off, then 1 kW from the battery bank)
(If battery bank is empty, then the genset kicks in and supplies the 1 kW to Load, the rest is charged into the battery.)

Yes, you can charge at the same time.

As promised here is the simple single line diagram.

I need to add grounding/earthing. SPD = Surge protection device.
@House: if I forgot something, please let me know.

battleaxe:
@House
If I have a standalone inverter(which has an inbuilt charger), plus a separate Charge controller, will it be possible for my batteries to get charged from both the PV array and the grid (if PHCN is available) simultanoesly?

Yes, there is a brand that has AC in where you can connect either grid or generator or you install a transfer switch, then you can connect to both, grid and genset.

I'll get back soon...

battleaxe:


If I understand this, this is a series parallel connection right? So we have 2 sets of 4 batteries connected in series.

4 batteries in series gives 48V, 200Ah.

2 sets of the above connected in parallel then gives 48V, 200Ah.

Is that correct?

If yes, I would like to raise the point made by @bigrovar on parallel connections. Will I have the same concerns with this? I.e difficulty in getting equal charge, inability to notice when one battery has issues this dragging others down etc.

This is ajo money! Want to be sure I put all the learnings here to play.

Thanks.

Mmh, what you see in my graph both constellations are in series!
On the left side it is "status quo" from kiekie1 and on the right side, that is my suggestion with shorter cables/bridges - still in series.

Regarding your question:
If you have four 12 V batteries in series with 200 Ah, then you have 4 x 12 V x 200 Ah = 9600 VAh (whereas you should only use 50%!).
So if you have two banks with four 12 V batteries each, then you have 2 x [ 4 x 12 V x 200 Ah ] = 19200 VAh
BUT for your application you will need C5 or C10 = 200 Ah. Mostly, 200 Ah on the nameplate is C20 or even C100.
So please double check the specs. 200 Ah without C indication does not tell the full picture.

[EDIT]
OK, no problem, I ignore it. But I leave my last paragraph for the house to read.
@ all: when you have a 48V set-up, you need to make sure that all batteries are well vented, in order to have similar temperature.
Why? Different temperature, different resistance, different performance, different chemical reactions inside the battery.
In the long run, assymetries cause inefficiencies and early stress for the poor performing once, which does accelerate the degradation.
In a 48 V set-up, I recommend a balancer that checks the mid-point voltage as well. And I recommend to rotate the batteries from time to time.
...
p.s. I am not here to sell, I am here to share my experience and to support my fellow solar installers.
I will post some pics in the future.

Funny, that people still think that Canadian Solar is a Canadian firm!

It was a good marketing act!

It is Chinese. It was later that they opened a panel factory in Ontario, Canada in order to meet the local content criteria to get the high feed-in tariff. But after the feed-in tariff system fell apart, and the province Prime Minister stepped back, I'm not sure, it that factory still exists.
Pure politics!

Can someone upload a picture of the name/type plate?

It will say "Made in China". I will bet a box of beer

How about this battery setup?

Original picture by kiekie1

earthrealm:
so i have 4units 24v 250w usa renogy panels, am thinking of upping my setup to 1500w, ie adding 2more units of 250w panels, my problem is that i cant get the renogy panels anymore, thus am forced to mix the panels...maybe yingli or sunworld.
so i will have 2 strings of 3 panels each feeding my 60amps mppt epsolar CC.
i hope my plan of mixing the panels isnt that bad?.. would try to match the voc, and vmp as much as i can, i intend to also swap out my #10 guage running from the panels to the CC, to a bigger cable

Hello,
please check I sc (=short circuit) and I mpp (=maximum power point). No need to check U oc (=V oc) and U mpp (=V mpp), in my opinion.

This would be my suggestion: choose a solar panel with the same cell type. mono -> mono; poly -> poly. Why? So that you have similar temperature efficiency coefficient.
And with similar or greater I sc and I mpp of your existing solar panels. Why? Because you do not want the new panels to limit the existing panels. If you choose smaller I mpp, then you loose energy. The panel with the smallest I mpp is your bottle neck!
String A: (+)--[old]---[old]---[new]--(minus)

String B: (+)--[old]---[old]---[new]--(minus)

I (String A) = I (String B)
I (old panel) = I (new panel)
U (String A) = U (String B)

As long as I mpp and I sc is not smaller, then you could go for 260 Watts or 270 Watts panels.

But U oc (String) = U oc (old) + U oc (old) + U oc (new) = U oc < U (DC/PV in of solar charger)
The solar charger must be able to cope with the total U oc. Otherwise your MPPT won't work.

@all Hybrid inverter owners:

Hello,
has anyone of you put an oscilloscope to his Hybrid inverter's AC output? What is the quality of the sine wave?
Can you please make a picture and upload it here?

Since poor quality/non-sine wave can destroy electric engines in the long run, i.e. German Liebherr fridge does not provide warranty when run on inverters. Or water pump should run with digital frequency converters, that provide pure sine-wave.
So, the quality of inverter you get is what you pay...