@ George,

i have been following your posts and i am quite impressed with your practical knowledge of solar energy. I have learnt quite a few things from you.

I am an alternative energy afficianado and i have done a few small installations, i am thinking of going into it full time. I have been searching for durable components, like solar panels, inverter, controllers, batteries and monitors/meters. I will contact you for advice on some component i am looking at.

But my main reason of posting this is for you to share your experience with one small overlooked issue in solar energy usage but which can have a profound influence on its reliability - which is the problem of DUST. How do you handle the issue of dust?

I did a 800 watts solar installation for a friend late June, and everything went well till December. The solar panels were supply expected power, but with the coming of harmatan dust, the supplied power has greatly reduced. Now we hardly get up to 40% of expected power as the panels are covered with a brown layer of dust. So we are thinking of hiring people to climb the roof and physically wash the panels (the building is one storey building so it would not be easy). This means incuring unexpected maintenance costs. Also we do not know how often we would need to wash the panels to achieve maximum power harvest during the harmatan period.

Considering this is lagos and a small installation, how would this problem be tackled in the case of a large installation in the very dusty north?

I just want to know your experience with the dust issue.

wirinet,
you are very right in your observation. dust is a major setback for solar panel performance in this part of our world.
if you noticed in one of my replies to ile naira posts, i did mention this problem. personally also, my solar array is
also suffering from loss of output due to the dust problem. for instance sometime last year i was hitting almost 50a
steadily with full sun on my array but now even with the addition of two extra panels combined output cannot even hit
40a!
how do we overcome this problem? the simple but more expensive method is to employ external washing of the panels - as
you suggested. but if you can't afford that or if this will be difficult to achieve (as in your case with the storey
building) it is best to allow nature clean the panels for you. after now, the rains will set in and the panels will be
sparkly clean again. all we have to do is to bid our time and pray for the rains.

then for the north that hardly have rain until late in the year, it becomes more dicey as the limited production of the
panels between raining seasons may be a dis-incentive for solar power unless there is a cost-effective way to wash
them externally.

@ wirinet, I think it is also important to think about this issue of dust before installing the panels. You could choose the part of the roof that is easily accessible.
I also asked George how he was managing it in one of my posts considering he has close to double digit panels now if not more and they are installed on the roof of a storey building.
In my own case, my house is a bungalow and I decided how I will be cleaning the panels before installation. I just borrow my wife's bucket and mop, hop on top of my ladder and the panels are cleaned but I have only 6panels.

bodejohn!
ha, ha, ha! you mean you actually borrow madam's mop and climb a ladder to clean your panels?

well, that is sometime!

talking of solar panel performance, it seems each region of the world has its own issues. in cold
climates their own problem is snow. the panels become enveloped in several inches of snow and they
have to devise a means to externally remove this. well, for us here, it is dust. huh!

George_D: wirinet,
you are very right in your observation. dust is a major setback for solar panel performance in this part of our world.
if you noticed in one of my replies to ile naira posts, i did mention this problem. personally also, my solar array is
also suffering from loss of output due to the dust problem. for instance sometime last year i was hitting almost 50a
steadily with full sun on my array but now even with the addition of two extra panels combined output cannot even hit
40a!
how do we overcome this problem? the simple but more expensive method is to employ external washing of the panels - as
you suggested. but if you can't afford that or if this will be difficult to achieve (as in your case with the storey
building) it is best to allow nature clean the panels for you. after now, the rains will set in and the panels will be
sparkly clean again. all we have to do is to bid our time and pray for the rains.

then for the north that hardly have rain until late in the year, it becomes more dicey as the limited production of the
panels between raining seasons may be a dis-incentive for solar power unless there is a cost-effective way to wash
them externally.

thanks for your assessment. We will have to put dust management into consideration when designing a solar system. For small installations, we have to make sure we have easy access to the panels for cleaning purposes, and for large installations a kind of sprinkler system could be incorporated.

George_D: wirinet,
you are very right in your observation. dust is a major setback for solar panel performance in this part of our world.
if you noticed in one of my replies to ile naira posts, i did mention this problem. personally also, my solar array is
also suffering from loss of output due to the dust problem. for instance sometime last year i was hitting almost 50a
steadily with full sun on my array but now even with the addition of two extra panels combined output cannot even hit
40a!
how do we overcome this problem? the simple but more expensive method is to employ external washing of the panels - as
you suggested. but if you can't afford that or if this will be difficult to achieve (as in your case with the storey
building) it is best to allow nature clean the panels for you. after now, the rains will set in and the panels will be
sparkly clean again. all we have to do is to bid our time and pray for the rains.

then for the north that hardly have rain until late in the year, it becomes more dicey as the limited production of the
panels between raining seasons may be a dis-incentive for solar power unless there is a cost-effective way to wash
them externally.

thanks for your assessment. We will have to put dust management into consideration when designing a solar system. For small installations, we have to make sure we have easy access to the panels for cleaning purposes, and for large installations a kind of sprinkler system could be incorporated.

wirinet,
for large installations - especially those on ground mount, i think a sprinkler system will not be out of place.
but for smaller units mounted on the roof like mine, i wonder how easy it will be to climb a ladder every now
and then just to wash the panels. i'm still looking at the work ability or otherwise of that method.

@all it seems we dont have interest in wind turbine here in nigeria..... Pls house what are the barriers am likely to face if i have to go by the way of a wind turbine adding it to my small setup? Whats is the average wind speed for Lagos?

@bing, compared to the relative certainty of the sun rising each day, wind turbines will always come second unless you're in a coastal area (even that offers no guarantees). As far as I've seen, domestic use of turbines has always been in conjunction with solar or hydro, rarely is it applied on its own. Large scale grid applications of turbines tends to be in high altitude or off-shore locations.

I don't know the average wind speed in Lagos, but I do know that a 3 storey building can spring up in a street designated for bungalows and nothing will happen. You might stand a better chance if wind flow is not blocked in such a way.

@ all, I was actually attracted to renewable power with what I saw in Europe. I saw a wind turbine farm while travelling on a train in Germany, although they are very tall, I didn't notice any river close to them. Also with the advancement of technology turbines with very small wind speeds are been developed.
I will advise that no one should doubt what technology advancement in that piece of equipment has become.

Meanwhile, I think my setup is breaking the record again, 121Ah harvested today, what a day! Expect the picture tomorrow.

@bodejohn, the turbines in Europe are in vast open fields and not not built up areas, that's a big difference. Also, domestic installations in Europe may have a better chance of working due to enforced town planning laws.The same cannot be said of what typically obtains in Lagos for example.

By 'coastal' in my last post, I was referring to the sea rather than river. So countries with wide coastlines rightly exploit it. Scotland and Sweden for example, have huge wind farms because of their coastal terrain.

@ Ile naira, I was referring to coastline by saying river, the example i sighted are also large scaled, like the suzlon advert you see on CNN. I have a friend who installed a wind turbine for his personal use in Lagos.
Although I do not have the details of the wind speed and how high it is, he told me it is working fine.
He was the one who told me about the turbines that work with really low speeds, can't remember the figures now.
What I am saying in essence is that, there are lots of myths around these things. For example, a lot of people think I am crazy for investing this much in alternative power. The only way to dispel these myths is by doing active research and investing...
You know oga George's signature now...

my bothers thanks for the quick response... Still on my research mode....

bing,
just like ile naira and bodejohn have rightly said, its not as if we don't have interest in wind turbines in nigeria
but due to the peculiar nature of our terrain as compared to other countries, wind turbine is not that attractive as
a viable renewable power resource.

apart from the northern part of the country where wind speeds are pretty high, using wind turbines in the west, east
or south could be a very risky venture without first of all doing a comprehensive site analysis which will give an
accurate picture of what wind speed to expect all year round. its no use installing a 3kw wind turbine that sits
idle for most part of the year without producing even 1w of power!

another thing going against deployment of wind turbines as compared to solar is the higher cost and non - flexibility
of installation. by this i mean if you're planning to install a 3kw wind turbine for instance, there is no incremental
way of doing this. you either save enough money to buy it in one piece or forget about it. for solar power however,
you can always start small and continue increasing your solar array until you reach your goal.

these are some of the drawbacks of wind as compared to solar as it applies to this part of the world but with a little
bit of ingenuity and research on our part, wind could become even as popular as solar power as far as renewable
energy goes.

Bodejohn,pls i will call you tomorrow to ask some questions from you.

@george thanks... I stay in a rented apartment for now and that was what brought about the wind turbine consideration.... If i get the go ahead signal from my landlord then its going to be solar all the way...

bing,
ok, i can now better understand your situation. don't worry. in time to come you will be smiling in your
own abode.

as for solar, you don't have to install on the roof like most of us. in fact another better way is to raise
a pole (like a water tower) and place the solar panels on top. that was what one of us did (mr butoneday)
before he eventually opted for his roof top - even though he's staying in his own house.


again, for the wind turbines, you can get a small portable type and depending on which direction your
house is facing, you can still install this and get some reasonable energy harvest from this.

unfortunately though, one of the wind data i've seen for nigeria is rather discouraging. as you can see
below, apart from the north which has an average wind speed greater than 4m/s every other part of the
country falls below this margin. depending on the model, most domestic wind turbines have a cut-in speed
of about 2m/s but to get reasonable energy harvest year round the wind speed in your area should ideally
be about 5m/s or more.

Oga George and bing, like I said earlier, I asked my colleague who installed the wind turbine, his works at 1m/sec. I have not seen his setup but he is someone I trust.

bodejohn,
nobody is doubting you at all. i was only speaking on general terms.

i think wind turbine technology is improving and getting better year on year.
most modern domestic turbines between 1 and 2kw certainly can operate efficiently
with a cut-in speed of 1m/s and they are the types you can easily hang at the rooftop
of your house. you don't need expensive pole mounts for those.

try and find out more details from your friend vis - model of wind turbine he is using,
power rating (kw) and price. i may be encouraged to incorporate this into my
renewables plan if the pricing is right.

Hi all,
I've finally got my MPPT controller, and 3 x 24v x 250W panels (sharp). I also got opportuned to get 4 x 100AH 12v batteries sold by a firm. I've contracted a welder to fabricate the base for laying the panels on d roof.
Over the weekend, in preparation, I added the 4 battery to the existing 4. So I have 2 battery banks now. One is 4 x 100AH 12v and the other is 4 x 200AH 12v (Hope the difference in AH isnt a problem?)

Each of the battery bank is connceted in series to get 48v and both banks are joined in parralel via 2 cutout fuses. One cutout is for the positive of both battery banks and the other is the negatives. The inverter DC/battery leg was connected to these cutouts (+ve & -ve respectively).

The inverter receives AC supply via a PRAG 10kva stabilizer. All connection are made with 10mm multi-core power cable.

So the outstanding thing now is to place the solar panels on d roof and run the wire down to the MPPT controller and battery (via the fuses).

The 2 battery banks read 50.4v after connection. I was able to also charge them with my Gen and used the inverter overnight.

I will later upload the pics. For the Gurus in the house, please can you help confirm if my setup is OK especially as it concerns the 2 battery banks with different Amp hour ratings, before i proceed further?

Cheers

life707:

1000Ah/2volt batts are available for sale: pix below. Contact:-life707@rocketmail.com

@life707, do you still have these how much per unit
@akanniade, are you wiiling to share the contact of your 2v batt.supplier?
My port troubles has denied me batteries. Any suggestions?

ile naira:
@life707, do you still have these how much per unit
@akanniade, are you wiiling to share the contact of your 2v batt.supplier?
My port troubles has denied me batteries. Any suggestions?

I got mine thru a friend in a telecomm company. They were phasing out the 2v volt type back then replacing it with 12v slim profile type.
Another guy I know, says the 2v used battery is available in the market, 1000ah 2v. His name is Arthur 0702 580 3611

Thanks akanniade, I'll give Arthur a call.

@pdozie, it sounds like you're on the right track with the info. you've given. I'd be very wary of mixing old and new batteries though, the lowest common denominator usually wins, i.e. your new batteries will be 'dragged down' by the weakest . You may be better off with just the new batteries.
I also hope they are all of the same current and voltage rating.

edit:
If I read your post correctly, I think you just have one 'bank' rather than two. You have a set of new batteries(4 in series for 48v) and another set of 'old' batteries also of 48v. Left at that, you'd have two separate banks (at however many amps), but since you've then conected both sets in parallel to increase your amperage, they become one bank of 48v and the combined amperage of each set.

@ Ile naira, I also strongly think it might not be a good idea to combine the batteries the way you have done.
Infact this the biggest drawback that I have noticed in starting renewable energy from a small level.
In rear cases that batteries can be combined, they have to be from same manufacturer, same AH, same model and age.
Like it was rightly pointed to you, the different brand of batteries have different charge and discharge curves specified by their manufacturers. This could even make your setup dangerous as I think you risk explosion of the batteries.

I will suggest, that you use the new set of 100Ah batteries you got or better still the older set alone.
You can google more on it.

Thanks Guys,
So I must maintain one battery type with same AH? that means buying the 4 x 100AH was a waste of money since the old ones are still game....

As adviced by Bodejohn, I googled it up. While many are against it, a particular blog wasnt convinced its a bad idea: http://www.morganscloud.com/2011/10/03/mixing-battery-sizes/

I will however disconnect one bank for now till further notice

pdozie: As adviced by Bodejohn, I googled it up. While many are against it, a particular blog wasnt convinced its a bad idea: http://www.morganscloud.com/2011/10/03/mixing-battery-sizes/

I will however disconnect one bank for now till further notice

I checked the link you put up there, like I wrote in my first response, the rear case that you can combine must be same brand and model with close matching age i,e date of manufacture. You will see this also in the article.

But in the case of ile naira, they are different brands.

bodejohn:

But in the case of ile naira, they are different brands.

Que pasa? Me no understand

@pdozie, it is probably safer to use one set. For how long have you had both sets of batteries connected?. Did you notice anything about the batteries? You seem to have verified the voltage across the resulting bank, did you do the same for current? I feel your concern about seemingly wasting a set of batteries but whichever way you decide to go, your purchase is not a waste. If you're confident everything checks out, use them all as plannned otherwise, sell one set and buy more of whichever set you've retained.

ile naira:
Que pasa? Me no understand

No mind me jare, I meant pdozie.

ile naira:

@pdozie, it is probably safer to use one set. For how long have you had both sets of batteries connected?. Did you notice anything about the batteries? You seem to have verified the voltage across the resulting bank, did you do the same for current? I feel your concern about seemingly wasting a set of batteries but whichever way you decide to go, your purchase is not a waste. If you're confident everything checks out, use them all as plannned otherwise, sell one set and buy more of whichever set you've retained.

I just started using both sets over the past weekend. They are still operational. Yea, I used my meter meaure the voltage. When the inverter said 'battery charged', I got 51.8v. I really dont know how to measure the current. If I put the meter terminals on the +ve & -ve of the batteries and push the meter button to Amp, it doesnt read anything. Please advice....

For now everything looks OK. I havent disconnected one set yet. I will probably leave it intact till this weekend fter I connect my solar panels then I can monitor for a while.
Please someone help me confirm how to use the digital meter to measure Current accoress the batteries.

Cheers

pdozie:

I just started using both sets over the past weekend. They are still operational. Yea, I used my meter meaure the voltage. When the inverter said 'battery charged', I got 51.8v. I really dont know how to measure the current. If I put the meter terminals on the +ve & -ve of the batteries and push the meter button to Amp, it doesnt read anything. Please advice....

For now everything looks OK. I havent disconnected one set yet. I will probably leave it intact till this weekend fter I connect my solar panels then I can monitor for a while.
Please someone help me confirm how to use the digital meter to measure Current accoress the batteries.

Cheers

Careful there so you dont blowup your meter. The current limit (usually 10A) your meter can measure is usually printed near the socket where you plug in your positive lead for current measurement. Ensure the current you want to measure does not exceed your meter range. Otherwise go for a clamp on ammeter.

Akanniade:
Careful there so you dont blowup your meter. The current limit (usually 10A) your meter can measure is usually printed near the socket where you plug in your positive lead for current measurement. Ensure the current you want to measure does not exceed your meter range. Otherwise go for a clamp on ammeter.

@pdozie, Akanniade is absolutely right. I made the assumption you had an ammeter of the appropriate spec.