₦airaland Forum

bassdow:
These should do. Guess the pumping machine is between 0.5, 0.75 and 1HP. Probably run the heavier items during the day

rhosymedre:
Thanks again, appreciated.

I will still be grateful for further input especially on this issue: " I am confused whether 2 x 200ah Lifepo4 will be enough or whether a single 7.5kwh Lifepo4 battery is necessary ...."

rhosymedre:
Many thanks for reply.

For now we have decided to exclude air conditioners; so, something like

* 1 medium/large TV e.g. 40 inches and 4 small TVs of 24 inches each
* 1 standard fridge (nothing big) and one small deep freezer
* 1 water pumping machine
* About 8 standing fans (will go for low power consuming fans)
* All electric bulbs in a 5 bedroom house

Thanks again.

Note: I didn't just say Lithium battery is superior BUT I said Quality Lithium  battery

GloryJoyeux:
Hello,

When sizing your system an energy consumption audit is one of the most crucial steps. I can see that you also listed the electrical loads you intend on carrying in a latter post. Although this is different from a comprehensive energy consumption audit, I will work with that figure.

Firstly, you must understand there is always a strong tendency to improve on a solar system after it has been installed so a lot of folks just go big from the get go if they are able to afford it.

A crucial question is: are you sure you really do not ever want to run that air conditioner? I’m asking because it seems like you really want it included, but the truth is, if you want it down the line, you will have to upgrade your system. Now, the ability to upgrade your system down the line is also a major advantage of residential ess, it means you can do what you can afford now and with time get to were you want it to be.

Answering your questions:

Battery size : Two paralleled 200ah battery is 51.2v x 400ah = 20kwh. That is over double the capacity of a single 7.5kwh battery. Both of these can power your air conditioner and other systems mentioned during the day with your 7.5kw inverter. However, at night, if you use the air conditioner with the 7.5kwh battery, you will quickly run out of stored energy. But the 20kwh battery will be more than enough to run your ‘inverter’ air conditioners over night.

By now I’m sure you are understanding the concept? Bigger batteries mean more energy stored for when there is no sunlight, it means longer run time of electrical load and means an extra day or two of autonomy.

Days of Autonomy : this is also a major factor when designing systems. In Nigeria right now we are at the raining season and this means poor solar yield. You therefore need to design a system that can go through at least a day of poor solar yield i.e. a full raining day where your batteries would just add 10 percent charge.

The larger 20kwh battery will enable you to plan 12kwh for the night, and the balance 8kwh for the next night incase there is poor solar yield due to rainfall.

The 7.5kwh battery means you will have to plan 4.5kwh for the night and 3kwh for the next night incase of poor solar yield.

Now, it all depends on energy consumption. Someone might be very okay on 7.5kwh inclusive of days of autonomy, while another will be okay with 20kwh, some have up to 90kwh as home ess.

Solar generation : I see you listed 4 units of 580w solar panels. This is 4 x 580w =2,320 W. Now, you must understand that you will hardly get a sustained 2,320w of solar yield. Always aim for 90 percent solar yield which is 0.9 x 2320w =2,088 W. Now you must consider inefficiencies when converting current and voltage to charge the batteries. Expensive inverters and solar charge controllers like make by victron offer way higher conversion efficiency. But, most cheaper inverters we use offer poor efficiency. So let’s go with 85 percent conversion efficiency. We have 0.85 x 2088w=1,774.8 W. Since you battery is 51.2v, it will charge at average of 53v so we have, 1,774.8w / 53v = 33.4 amps.

Take note of the figure 33.4 amps. If you go with the 7.5kwh battery which is 150ah. It will take up 150ah / 33.4amps = 4.5hrs sunlight to charge. Now notice if you go with the 20kwh battery which is 400ah it will take up to 400ah / 33.4amps = 12hrs sunlight to charge

This above is only accurate if you are not running a single day time load. Once you are running a load during the day eg your freezer is turned on. Then, your 1,774.8w from solar panel will need to power those loads first, before sending the balance to the battery, meaning you will be looking at 27amps or even just 25amps charging current.

Now, not all sunlight is equal. Just because it’s daytime doesn’t mean you will be generating such high sustained figures. For a fact, you can only expect such sustained performance all day only during the dry season in the south, except you are living up north in Nigeria.

We can therefore conclude that your solar panel is completely underpowered.

How to size your solar panels : I will give you my personal calculation that works for me always. If you are resident in the south of Nigeria, size your panels to fully charge your batteries with just 1.8hrs of sunlight i.e 1hr 48mins of sustained peak solar pv should charge your battery to full. If you are in the North use 2.5hrs of sunlight for your calculation.

This means that, to size your panels divide your total battery capacity by 1.8 if you live in the south and 2.5 if you live in the north. So 20kwh battery / 1.8 = 11,000w total panels and 7.5kwh battery / 1.8 = 4,160w total panels.

I can assure you, if you size your panels this way and factor in days of autonomy for battery size. Come rain come sun, out of 365 days a year, you will always get full charge for a minimum of 340 days. The remaining less than 25days which translates to 4 times a month in the rainy season, you can expect minimum of 50 percent charge.

Regarding questions 2 and 3. Do not buy from some alaba marketers, to be safe just go straight to their official distributors and buy from them. I have seen situations where they print new stickers with higher capacity and paste on their batteries to deceive unsuspecting customers. Do you research and ensure you purchase from the right source or you will not get value for your money. For the inverter part, you can maybe google search the name of the inverter and add words like ‘repair’ , ‘fault’ , ‘common issues’, ‘problems’ and see if you can find any known issues documented online. This is a neat trick for researching any electrical device you intend to buy.

*sorry for any typos, I didn’t proofread this.

justcallmenuel:
220Ah 12v super speed tubular battery available, #250,000. Call/whatsapp me on 08168986461

Dam5reey1:
Ibadan

DIY Build

Ithream:
I was discouraged by the prices. Moreover there is light in my area to an extent. Instead I add on top the money go buy land in one area of Ogun state. I’m now a landlord instead of a solarlord.

Ithream:
I was discouraged by the prices. Moreover there is light in my area to an extent. Instead I add on top the money go buy land in one area of Ogun state. I’m now a landlord instead of a solarlord.

Drgreatone:
Are the 2 batteries connected or u retiring the sako?

drizzle0007:
Good day everyone. Please I would like recommendations for a turbular battery of great quality. 220/12v preferable.

My budget is 250 and below. I would also appreciate recommendation for a 1100/12v inverter.

Please quote with your recommendations. Thank you so much

Dam5reey:
Both in parallel.

drizzle0007:
Good day everyone. Please I would like recommendations for a turbular battery of great quality. 220/12v preferable.

My budget is 250 and below. I would also appreciate recommendation for a 1100/12v inverter.

Please quote with your recommendations. Thank you so much

Ithream:
I was discouraged by the prices. Moreover there is light in my area to an extent. Instead I add on top the money go buy land in one area of Ogun state. I’m now a landlord instead of a solarlord.

GloryJoyeux:
The advantage of my properly sized ess. It has been raining since morning, however the rain has just stopped for an hour but you can see that in that 1 hour of less than ideal solar irradiation, the inverter has been able to store 100ah into the battery. Now, surely the rain will continue in the next hour or two, but between now and that time, I would have a full charge. This is despite 5 days straight of daily rainfall, I still get 100 percent charge within the very few windows of sunshine when the rain stops then continues.

The other thing is to make sure you always use quality panels, you can see my jinko PV1 is producing 5,156w out of a rated 5,280w. PV2 is also producing similar and all these is with the heavy loads in the house turned on.

HeavenlyBang:
Lifepo4 batteries are built for different voltages, unlike tubular that's only in 12v. You have to be more specific than "2x200ah".

A 12v 200aH Lifepo4 battery is 2.56kwh
A 24v 200aH is 5.12kwh
A 48v 200aH is 10.24kwh

GloryJoyeux:
Hello,

When sizing your system an energy consumption audit is one of the most crucial steps. I can see that you also listed the electrical loads you intend on carrying in a latter post. Although this is different from a comprehensive energy consumption audit, I will work with that figure.

Firstly, you must understand there is always a strong tendency to improve on a solar system after it has been installed so a lot of folks just go big from the get go if they are able to afford it.

A crucial question is: are you sure you really do not ever want to run that air conditioner? I’m asking because it seems like you really want it included, but the truth is, if you want it down the line, you will have to upgrade your system. Now, the ability to upgrade your system down the line is also a major advantage of residential ess, it means you can do what you can afford now and with time get to were you want it to be.

Answering your questions:

I will assumes you are comparing 48v batteries because using a 7.5kw inverter with anything less than 48v batteries system is poor design choice.

Battery size : Two paralleled 200ah battery is 51.2v x 400ah = 20kwh. That is over double the capacity of a single 7.5kwh battery. Both of these can power your air conditioner and other systems mentioned during the day with your 7.5kw inverter. However, at night, if you use the air conditioner with the 7.5kwh battery, you will quickly run out of stored energy. But the 20kwh battery will be more than enough to run your ‘inverter’ air conditioners over night.

By now I’m sure you are understanding the concept? Bigger batteries mean more energy stored for when there is no sunlight, it means longer run time of electrical load and means an extra day or two of autonomy.

Days of Autonomy : this is also a major factor when designing systems. In Nigeria right now we are at the raining season and this means poor solar yield. You therefore need to design a system that can go through at least a day of poor solar yield i.e. a full raining day where your batteries would just add 10 percent charge.

The larger 20kwh battery will enable you to plan 12kwh for the night, and the balance 8kwh for the next night incase there is poor solar yield due to rainfall.

The 7.5kwh battery means you will have to plan 4.5kwh for the night and 3kwh for the next night incase of poor solar yield.

Now, it all depends on energy consumption. Someone might be very okay on 7.5kwh inclusive of days of autonomy, while another will be okay with 20kwh, some have up to 90kwh as home ess.

Solar generation : I see you listed 4 units of 580w solar panels. This is 4 x 580w =2,320 W. Now, you must understand that you will hardly get a sustained 2,320w of solar yield. Always aim for 90 percent solar yield which is 0.9 x 2320w =2,088 W. Now you must consider inefficiencies when converting current and voltage to charge the batteries. Expensive inverters and solar charge controllers like those made by victron offer way higher conversion efficiency. But, most cheaper inverters we use offer poor efficiency. So let’s go with 85 percent conversion efficiency. We have 0.85 x 2088w=1,774.8 W. Since you battery is 51.2v, it will charge at average of 53v so we have, 1,774.8w / 53v = 33.4 amps.

Take note of the figure 33.4 amps. If you go with the 7.5kwh battery which is 150ah. It will take up to 150ah / 33.4amps = 4.5hrs sunlight to charge. Now notice if you go with the 20kwh battery which is 400ah it will take up to 400ah / 33.4amps = 12hrs sunlight to charge

This above is only accurate if you are not running a single day time load. Once you are running a load during the day eg your freezer is turned on. Then, your 1,774.8w from solar panel will need to power those loads first, before sending the balance to the battery, meaning you will be looking at 27amps or even just 25amps charging current.

Now, not all sunlight is equal. Just because it’s daytime doesn’t mean you will be generating such high sustained figures. For a fact, you can only expect such sustained performance all day only during the dry season in the south, except you are living up north in Nigeria.

We can therefore conclude that your solar panel is completely underpowered.

How to size your solar panels : I will give you my personal calculation that works for me always. If you are resident in the south of Nigeria, size your panels to fully charge your batteries with just 1.8hrs of sunlight i.e 1hr 48mins of sustained peak solar pv should charge your battery to full. If you are in the North use 2.5hrs of sunlight for your calculation.

This means that, to size your panels divide your total battery capacity by 1.8 if you live in the south and 2.5 if you live in the north. So 20kwh battery / 1.8 = 11,000w total panels and 7.5kwh battery / 1.8 = 4,160w total panels.

I can assure you, if you size your panels this way and factor in days of autonomy for battery size. Come rain come sun, out of 365 days a year, you will always get full charge for a minimum of 340 days. The remaining less than 25days which translates to 4 times a month in the rainy season, you can expect minimum of 50 percent charge.

Regarding questions 2 and 3. Do not buy from some alaba marketers, to be safe just go straight to their official distributors and buy from them. I have seen situations where they print new stickers with higher capacity and paste on their batteries to deceive unsuspecting customers. Do you research and ensure you purchase from the right source or you will not get value for your money. For the inverter part, you can maybe google search the name of the inverter and add words like ‘repair’ , ‘fault’ , ‘common issues’, ‘problems’ and see if you can find any known issues documented online. This is a neat trick for researching any electrical device you intend to buy.

*sorry for any typos, I didn’t proofread this.

bassdow:
Mentioning appliances such as Fridge or Freezer, or even Pumping machine, without mentioning their capacities means we either make guesses or give information that could end up being wrong.

We don't even know if your pumping machine is surface or submersible, let alone knowing it's capacity.

Even TV's power rating needs be stated as I have seen TVs that consume power like community cinema.

At end of the day, a larger battery bank would always server better than a smaller one irrespective of the number of units. In other words, 2pcs of 12v 200AH battery would always out perform 1pcs of 200AH battery all things being equal.

Now you probably are comparing 2 types of batteries => Lithium and Tubular/GEL/AGM batteries. Just understand that quality Lithium batteries gives much more power than Tubular/GEL/AGM of comparable capacity.

Note: I didn't just say Lithium battery is superior BUT I said Quality Lithium  battery

Major advantage Lithium technology has over Tubular/GEL/AGM is, you could run Lithium batteries lower (though help if you don't) BUT for the likes of Tubular/GEL/AGM batteries, you need ensure you don't run beyond 50% of it's stated capacity else it wouldn't be there to serve you for long.

NB: A lot of us want to quickly respond to comments and get on our way. Abeg no give us reason to stress our brain unnecessarily.
Consuming information such as "2pcs of 12v 200AH battery" is much quicker than saying "4.8kwh" BECAUSE we have to mentally do things such as convert 12-volts 200AH to kWh i.e; 200AH x 12v = 2,400 watts ÷ 1000 = 2.4 kWh

Anyway sha, the 2pcs of 200Ah batteries is much smaller and wouldn't last long in terms of years.. You would have better luck going with the 7.5kwh battery so long it ain't over-rated or low quality.

Once again, the above information could be wrong as capacity of the appliances especially the Fridge , Freezer , and Pumping machine weren't mentioned. Didn't even ask how long you intends powering them daily sef.

odimbannamdi:
...this gave me a very good laugh now...lol...

Now, let's get serious.

The truth is, solar inverter is a necessary evil that inevitably awaits anybody that values his comforts, productivity and wants cost-savings.

This because as long as you remain in this country, it is only a matter of time before the cycle of epileptic power supply either catches up with your area or they move your area to "Bandit A" and you will begin to wonder whether someone is putting hands into your pocket and zapping your resources through power bills. By then, you may then have to cough out x2 of your current budget to achieve what you could have achieve today.

Personal story: Last October, it cost 450k to convert my SUV to use CNG at NIPCO station. The money sounded very big and I disapproved it further by saying fuel was just 400+/litre, so why spend 450k to convert my car. I was so foolish...

Fast forward today, I spend nearly 200k every single month on fuel even though I drive sparingly. CNG conversion is now a whooping 950k, with serious shakara and lobbying. I am full of deep regrets for not doing it last year. By now, i would have finished bleeding off the 450k and recouped it through cost-savings

At the end, it is ultimately your decision

rhosymedre:
Wow wow wow! I'm thoroughly and totally blown and I am truly and deeply very grateful

The thing is that from what I have read here my understanding was that 2x200ah Lifepo4 (of the spec you've used i.e. 48v if I recall correctly) is a better option than a single 7.5v. I was therefore surprised when the installer suggested the single 7.5 over the two 2x200s.

I am now going to calmly and carefully go through your incredible post for better understanding as part of my research ahead of choosing/agreeing the system. I am truly very very grateful once again .... but don't be surprised if I come up with more questions or seek further clarification in the next few days please.

Thanks again.

Drgreatone:
Curious, why do u still want a tubular battery with all you have read here sir?

Drgreatone:
Curious, why do u still want a tubular battery with all you have read here sir?

Ithream:
I was discouraged by the prices. Moreover there is light in my area to an extent. Instead I add on top the money go buy land in one area of Ogun state. I’m now a landlord instead of a solarlord.

jonescosmos:
I respect your decision to buy land first, It's very good but don't also forget that the cost materials to develop that land will not wait around the corner till you are ready to develop it. Same goes to Solar and its likes.

Most of us who invested heavily in Solar have already became "Houses Lords" and we thought going solar should be a means of mitigating recurrent subscription based energy expenses.

One thing you should do is try to balance the savings, while you are trying to save to buy/build a house why not go solar now so that the money you would have used to pay for energy expenses will be diverted into the saving for the property of your dream.

kiekie1:
UP FOR SALE!

Victron bluesolar 12-48v 70a MPPT

Condition: Fairly used but functional . "LCD might need replacement"

Firm price: 180k

Location: Lagos but can be waybilled under buyers expense.

O8O35O31951

drizzle0007:
I haven't read much sir. I've used both a turbular battery and a portable power battery and the turbular battery last me x2 as more.

I have a really small set up and I just want something that would be great. What do you recommend?

what do you mean by "portable power battery" ?