hello jayboskie7,
you normally size your solar array according to your battery bank and load usage and not according to
your inverter capacity.

what load do you plan to run and what is the duration? with that you can calculate the optimum size of
your battery bank and also the size of your solar array.

@all, can anyone help me with understanding the port costs of importing batteries? I have 24 2v cells ready to ship but I have no idea of what to expect to clear it in Lagos.

The same applies for panels, what are the charges involved, what have people paid.

@George_D, have you ever come across a >90 amp charge controlller? I intend to have panels in series (48v) and parallel in a string. The output current will be 84amps (including 1.25 safety factor). Buying two chargers and connecting them in parallel is a expensive but there are not many cheap >90 chargers that I've seen so far.

Thanks

hello ile-naira,
i admire your courage in going the import route to get these items directly. truly this is the best option
for anyone hoping to get the best bargains on renewable energy products.

unfortunately i don't have info on clearing charges but i'm sure any clearing agent you contact can furnish
you with this.

for now the highest amp you can get from mainstream domestic charge controllers is 80a. the only increase is
on the open circuit voltage in which xantrex has come out with a 600v 80a model.

http://www.soligent.net/uploads/products/29403_3.pdf

most others like outback, tristar, steca, apollo, bluesky, midnight solar, etc all max out at 150v with varying
outputs up to 80a (however the midnite solar classic 150 charge controller can output up to 93a at
12v system voltage but drops to 83a when used with a 48v system).

http://www.wholesalesolar.com/products.folder/controller-folder/midnite-classic-lite.html

if you're looking for charge controllers that can output up to 90a and above i'm afraid you may have to look
at grid tie/modular types. for these you'll be looking at phocos, solatteck, sunnyboy, etc.

as for paralleling two charge controllers being expensive, i think you have to look at in another way. if you
already had a 45a charge controller of a particular brand and you're looking at increasing your solar array to
accommodate another 45a capacity set of solar modules, won't you rather pay extra money and get another 45a
charge controller of same product which would be cheaper than buying a single 90a charge controller of a
different brand? i leave the question for you to answer.

Thanks for the reply George. I happen to be out of the country for about 3 months a year so i can get most things and carry it in my bags. But panels and batteries?,

F.y.i, Apollo solar do the T100 turbocharger (100 amps) as do Microcare in South Africa but they are super expensive. I think I have to do the dreaded stacking as you've suggested. I just dont want to make a mistake and end up frying expensive equipment. I'm actually starting from a clean slate hence the reluctance to buy 2 chargers

Thanks anyway and I'll be sure to share the build once started.

ile-naira,
i just finished checking the apollo t100 charge controller and i must say it's a tempting piece of equipment to have.
looks like they upped the game from t80 which used to be their flagship:

http://apollosolar.com/LinkClick.aspx?fileticket=3XtF1cd6dRs%3D&tabid=143

still, if you're building your system from scratch, you have the luxury of choosing from these high end offerings
especially if you have an eye for future expansion. however if you're already on the renewables bandwagon like myself,
its plenty difficult switching over to something not quite tested yet, and again when you consider that the product
you happen to be using presently is one of the best industry-wide.

stacking of controllers may not be as 'dreadful' as you make it sound. even with the higher output models, a time comes
when you just have to keep adding like for like if you want to increase power output. same goes for inverters - well i
mean the high end types.

please do let the house know when you eventually succeed in putting your system together. i'm sure we all want to learn
a thing or two from you.

What can i say.... am more than impressed and i have learn many things from you guys.. More strength to your elbow. 3.5kva inverter now installed and working fine. phcn cost now reduced and saving for the solar panel now..

deeplo,
congrats on the successful installation of your 3.5kva inverter system. now you will be free from the clutches of
generators for a while.

ile-naira,
still on the subject of stacking, i want to chip in a quick note:


even with a well-planned forward looking system, stacking of charge controllers and inverters is never
out of place. this is so primarily due to the huge advantages it affords.

assuming i have a large household which needs about 6kw of power to run it. but this 6kw is only needed
at peak hours of the evening when everybody is at home. it would be wiser for me to install 2 sets of
3kw inverters stacked, such that in the mornings or during low power demands, only the master inverter
(the first 3kw inverter) will be on duty while the slave (2nd inverter) will be on standby mode waiting
until there was peak demand before it can swing into action. this helps to conserve much needed power
that would have been wasted if i had a single large 6kw inverter running all the time.
still following the example above, 2 sets of 3kw inverters stacked together will enable me continue to enjoy
power even when one of them is taken out for service. and then imagine if you had a single large 6kw inverter
that suddenly went bad! you'd be out of power for as long as it takes to get it fixed or maybe you'd switch
over to noisy generators for that period. but with 2 stacked 3kw inverters, the two cannot get bad all at
once.

same goes for charge controllers. if i had a single large 90a charge controller and it was affected by
lightening that will mean no more solar charging until it was repaired or replaced. but if i were to stack
2pcs 45a charge controllers even if one of them were to malfunction, i would still have one left to do
the charging.

so, as you can see apart from having no choice but to stack when you want to increase power, stacking
still has other advantages and is highly recommended when dealing with renewable energy.


another quick note: not all inverters or charge controllers can be stacked. it is very important to read
oem manuals for whatever brand you're installing so as to get a handle on what steps need to be taken for
proper and safe stacking and what accessories are needed to achieve this. this is so that you don't
endanger yourself and your property.

Oga George, you are quite right about making the system flexible with stacking.
In the manufacturing industry, we sometimes call it redundancy.

One very important question, is there any comparison between the depth of discharge of a battery and it's Open circuit voltage?
For example, can I say that my battery is at 50% dod at 24.5 volts? Approximate values.

hello bodejohn,
yes, you can estimate the state of charge (soc) or depth of discharge (dod) of a battery using its
open-circuit voltage. however, depending on the internal cell conditions of the battery, it may not
be a very reliable way of determining the battery's residual capacity. for this you need other means
of calculating amps in and out in real time. this is achieved by incorporating gadgets such as
a battery charge monitor (bmk) or the trimetric.

all,
pictures of stacked charge controllers and inverters from across the world:

more:

Hello guys, I ended the month of January with 1,418Ah of free energy from the sun.
Assuming an average of 24V, that equals a total of 34,032Wh approximately 34KwH.
While this looks like much for a beginner, I am setting my sight to double this before the end of the year.

Only disappointing is that I only have to pay less than 500naira to PHCN for same amount of power.
PHCN charges 12.5naira for 1 KwH in my area, so 34 X 12.5 is just 425naira, ofcourse the story will be light years different if I had to run on generator.

Ok, charge controller data storage reset back to zero, it's the beginning of a new month. Happy new month folks!

bodejohn,
congrats to you! in terms of payment to phcn, your solar harvest may appear very insignificant
but when you factor the convenience and not having to listen to all that deafening gen noise
coupled with the knowledge that you're now independent from frequent power outages, the gains
quickly add up.

George, apologies for the late reply, I've been busy looking into my fears about the Lagos port and it's not good. I have had to let go of the 2v cells I was going to import. Everyone to a man said DON'T DO IT! Not with batteries anyway

On the plus side, I completely agree with you, I looked at my array design again and I've increased the voltage but reduced the current by tweaking the series/parallel layout.
I will not be needing an expensive 90 amp inverter anymore. I'd decided on 2 x 60A charge controllers anyway (to minimise damage risk and future expansion purposes just as you've implied). The charge controllers are fan-less like your Tristar which makes them smaller and less complex. I'll go and look at stacking two 3 Kw inverters too. Thanks.

Out of interest George, did you carry out any roof-loading calculations before mounting your panels on the roof?. The destination for mine is the flat roof of the car port (the optimum tilt for me is 5 degrees anyway). I could expand by using the main roof but I'd have to get up and have a good look to even begin to think about it.

George_D: ile-naira,
still on the subject of stacking, i want to chip in a quick note:


even with a well-planned forward looking system, stacking of charge controllers and inverters is never
out of place. this is so primarily due to the huge advantages it affords.

...........................
still following the example above, 2 sets of 3kw inverters stacked together will enable me continue to enjoy
power even when one of them is taken out for service. and then imagine if you had a single large 6kw inverter
that suddenly went bad! you'd be out of power for as long as it takes to get it fixed or maybe you'd switch
over to noisy generators for that period. but with 2 stacked 3kw inverters, the two cannot get bad all at
once.

same goes for charge controllers. if i had a single large 90a charge controller and it was affected by
lightening that will mean no more solar charging until it was repaired or replaced. but if i were to stack
2pcs 45a charge controllers even if one of them were to malfunction, i would still have one left to do
the charging.

so, as you can .....................................


another quick note: not all inverters or charge controllers can be stacked. it is very important to read
oem manuals for whatever brand you're installing so as to get a handle on what steps need to be taken for
proper and safe stacking and what accessories are needed to achieve this. this is so that you don't
endanger yourself and your property.

get solar charger for your mobile phones,ipod,ipad,digital camera for just 5500 naira[40 dollars]. U can contact me on 08130161937

Pls enlighten me further:
1.This charger booster can it work alone on low amperage from public power supply?
2.If yes,how much is it?

ile naira: George, apologies for the late reply, I've been busy looking into my fears about the Lagos port and it's not good. I have had to let go of the 2v cells I was going to import. Everyone to a man said DON'T DO IT! Not with batteries anyway

On the plus side, I completely agree with you, I looked at my array design again and I've increased the voltage but reduced the current by tweaking the series/parallel layout.
I will not be needing an expensive 90 amp inverter anymore. I'd decided on 2 x 60A charge controllers anyway (to minimise damage risk and future expansion purposes just as you've implied). The charge controllers are fan-less like your Tristar which makes them smaller and less complex. I'll go and look at stacking two 3 Kw inverters too. Thanks.

Out of interest George, did you carry out any roof-loading calculations before mounting your panels on the roof?. The destination for mine is the flat roof of the car port (the optimum tilt for me is 5 degrees anyway). I could expand by using the main roof but I'd have to get up and have a good look to even begin to think about it.

hello ile-naira,
thanks for getting back. no, i didn't do any roof-loading tests (although i know that was the right thing to do). and to be honest, i was a little bit worried initially when i started increasing my solar panels but after a while i guess i became relaxed when i saw that the roof
structure was solid enough to withstand the extra loading. if i had enough space in my compound, honestly i would have gone the way of akanniade using a car port or like yourself but there was just no way to do that without causing extra shading of the panels from the main building.

as for the optimum tilt being 5 degrees i quite agree with you but again you have to remember that it will mean the panels will be lying (almost) flat to the horizontal. when newly installed you get optimum solar harvest with this inclination but with time a thick layer of dust might eventually settle on them which may not be easily removed by rain. so perhaps you may have to start thinking of incorporating periodic roof washing if you want your panels to continue performing at their best. just a thought.

George_D:

................ i became relaxed when i saw that the roof structure was solid enough to withstand the extra loading...............

you may have to start thinking of incorporating periodic roof washing if you want your panels to continue performing at their best. just a thought.

It's good your roof is solid. I'll check mine If I can use the roof then I can have more panels and let the rain and gravity do the washing.

I found inverters that were designed to be stacked and the best thing is they are not the expensive Outback/Xantrex examples. I've asked for the specifications from the manufacturers. Still waiting. Oh, the first of my PV project material turned up today. A DC Isolator. I just need everything else to connect it to to arrive.

@George_D and every one in the house.

I have been silently following this thread on and off for two years now. I find it quite fascinating. I have learnt so much from this thread. You all have inspired me to setup my own Personal power project but I intend to start small. I don't have a lot of money to invest in it now. So I intend to start with just a 1.5-3.5 kva inverter and 2 batteries.

I just recently found out that a friend of mine is into inverter equipment sales and installation. He told me about one Sumo inverter. It is a 24v inverter system. It is made in India. He even said they are better than Sukam and cyber power inverters as it contains more features than other inverters. And it is actually very cheaper than other inverters.

So my question is, has any hears of Sumo Inverters?. If yes, how durable are they?. Is it worth it to start my power project with it?.

ile naira,
i can see you're preparing very hard for this project of your. a dc disconnect (isolator) is absolutely essential
for safety of your equipment. i intend to incorporate that in my next upgrade.

exactly what brand of inverter are you getting? do be careful not to buy one that my not work as claimed.

inverters are the heart of any renewable energy system and its always advisable to go for the best brand you can
afford. believe me, skimping on inverters do hurt in the long run. reason: unless you plan to run your system fully
on solar power, a poor inverter will give you below average charging performance which in turn will affect battery
life. a poor and inefficient inverter will keep depleting your battery bank for the same amount of power for less
run time compared to a high quality one. lastly, a poor inverter will most likely require costly repairs in the
short term and in the long run may require frequent replacement.

George, if you need isolators or dc breakers let me know. I can pick them up as I get mine. The same for busbars and terminal blocks.

The inverters that I've seen are from China

(here's a not so great advert for it on you tube, the guy had wired them incorrectly)
https://www.youtube.com/watch?v=N8M9A8hd62E.

They are quite easy to set up and apparently have double their stated peak power as the surge rating. They can also be used individually if you want to dismantle your set-up or sell on in going to single inverter. I am just waiting for the specs first before I commit. The only downside I can see is that there is no display panel on them from which I can get feedback on power output /dignostics/ etc. I just cannot ignore them as the price for the 2-3 pieces I need will not even buy me one Xantrex or Outback equivalent, let alone 2.

If the specs don't convince, I'll stick to one inverter.

@ile naira, I did a quick search on google for the stackable inverters and found some produced by best power inverters from China.
I have grown to like patronize the folks in China lately because of their ingenuity and relatively cheap products.

My pure sine wave inverter and MPPT charge controller which I got from best power inverters in China has so far worked to my satisfaction.
If you like adventure like me, you can go for them. I will consider getting one or two from best power myself.

Oga George, I have noticed, is more comfortable with products the industry leaders and you know he is very close to oyel.

@ile naira, I did a quick search on google for the stackable inverters and found some produced by best power inverters from China.
I have grown to like patronize the folks in China lately because of their ingenuity and relatively cheap products.

My pure sine wave inverter and MPPT charge controller which I got from best power inverters in China has so far worked to my satisfaction.
If you like adventure like me, you can go for them. I will consider getting one or two from best power myself.

Watch out: I didn't see any pure sine wave that is stackable and it looks like it doesn't also come with battery charging features.

Oga George, I have noticed, is more comfortable with products the industry leaders and you know he is very close to oyel.

@bodejohn, you may have spotted something I missed : the waveform. Thank you.
In my excitement, I assumed it was pure sine wave. That's partly why I requested a spec sheet. I wasn't worried about batt charging, but an inverter is useless to me if not pure wave.
Damn, I have to forget that inverter and start looking again.

As for being scared of China/ the Chinese, the answer is yes and no. I have no problems with trade, friendship, partnership etc, but with a tilted balance of economic power and thieves in our government, I fear. Our continent and people have been through too much to sleep-walk or be sold into colonisation again. Anyway, this is not the politics section so I'll stop there.

ile-naira,
bodejohn,

you guys have spoken well but experience has shown that when it comes to renewables, the chinese
promise so much and deliver so little. apart from a few solar panels like suntech most of their
products are below standard. they may work well for a while, but that is so deceptive because in
the long run they won't give you value for your money.

as for going for tested products, it only makes sense to do this especially when it comes to
renewables. why would i buy a product that i need to keep replacing when i can get one that lasts
for a longer period without breaking down? why would i buy a product that promises to supply 50z
and 220v but ends up supplying 45z and 195v? or what would you say of a so-called 'pure sine wave'
inverter that performs more like a square wave inverter? i could go on but such are the antics
of the chinese.

so having experienced these first hand, it actually makes more sense to invest in tried and tested
brands that perform as claimed. if i install a fake solar panel on my roof just because it is cheap,
imagine the inconvienience of having to climb up that roof to change out panel after panel when i
discover it is no longer putting out even half its rated power! imagine the danger involved in
installing an inverter that goes up in smoke due to overheating because its fans failed prematurely!
imagine a charge controller that can't charge your batteries to full charge no matter how long it is
left to run? again, imagine a fried charge controller struck by lightning because its acclaimed high
voltage disconnet (hvd) feature failed to activate to protect the controller when it was needed most?

these products may be cheaper than the tested name brands but do they provide the same level of
performance? i think that is the question we have to ask ourselves first. personally it makes more
sense to spend money on an expensive produst that will serve the purpose than to try and save money
by buying cheaper alternatives only to have to replace them three times over within the same period.

that is common sense to me.

GD truly it is only few that knows and appreciate value for money products. this s d challenge we hv in d north.

George, very good points and well-made, but the willingness to try other manufacturers is not down to price alone, at least not for me. Innovative small companies, new-comers and established but unpopular old-timers all deserve a chance and a second look.

You're right about some dodgy Chinese products but you might also be doing the honest Chinese Manufacturers a disservice by lumping them all together. I think it is always the case of buyer beware and if in any doubt, go for the devil you know rather than the angel you don't. Me, I never just look and buy, I always get evidence of on-field use and opinions of such users before parting with my hard-earned money.

there is no need to talk about kva or what ever, as solar and wind turbine installer what determines your kva or wattage depends on your solar panels or wind turbine, battery bank, before you can talk about kva. you can have 3kva without having having a stable power, but for me since i'm an installer and you wish to have a steady power you can use (solar-wind turbine hybrid). with this you can have stored to your battery day and night. then as the vottage booster that can boost your battery current to preferable voltage also available but not in the Nigerian market. for more questions and installation i can take them all by phone: +2348060374072. or email: donushick@yahoo.co.uk. i am from port harcourt nigeria.

S-l-o-w-l-y getting there, more arrived today.

@ Ile Naira, you are my guy.
I wanted to pick that MPPT charge controller that you got there, it was the best i saw then, but it had too much than I needed.
CAN BUS, Ethernet, RS232 was just too much design and the cost of shipping was also high.
Although, I couldn't overlook the 130volts Vmp. But I sure will get one when I visit China next month.

@ Oga George, I quite agree with you 100% that one should not compromise on cost and quality when electronics like these are considered.
But I also think that some Chinese companies are worthy giving a try.

@ all, I hit an all time high of 74Ah harvest today, that's a whopping 1850WattHr power!