(By the way, Hoppecke in Germany has to provide a 7 years take-back warranty. So that people feel assured, that the manufacturer's promise of number of cycles is true. If not, Hoppecke has to take-back the batteries and pay the remaining "book value" of the battery to the customer.)

Hello @CoolKizzy,

your salon seems to be big? Nice!
Where are you located?

How much roof space do you have for solar panels? A 250 Watts(peak) panel is about 1,65 x 1,00m.

So, a solar system with 4 panels = 1.000 Watts(p) can produce up to 1,600 kWh per year in Lagos or between 80 and 130 kWh per month.
8 panels = 2.000 Watts(p) -> 3,200 kWh per year.
etc.

This is an example:
Voltage U(mp) = 29,7 V
Current I(mp) = 8,42 A
Short circuit I(sc) = 8,8 A
Open circuit Voltage U(oc) = 36,91 V

In the pic is my solar roof with six panels, where I grow my tomatoes.

@guitarlife: send me a private message with your request.

@shamecurls: I did not know that an inverter can be used for both directions: DC in, AC out and AC in, DC out?

Anyway, I'd recommend a smart battery charger with three phase/stage charging and <20 Amp (less than 10% of AH value) It takes longer to charge, but you don't stress the battery and have a longer battery life (i.e. more cycles).

@Charpell

Do you have a webpage, please?

sunny regards,

John

@Charpell

Do you have a webpage, please?

sunny regards,
John

Do you mean this?

iLoveTheSun:
Here is a 2 x 270 Watts(peak) off-grid garden project to power a waterpump (1000 W) and handtools to work.
QCells (Made in Europe) in series.
Batteries VRLA from Fiamm (Italian) 12 x 40 Ah(c10) = 480 Ah
Inverter (Danish/German) 1,6 kVA
Charger (Danish/German) 100 Volt, 15 Ampere

Thanks, for sharing the Vanguard news article!
146m USD for only 75 MegaWatt is amazing.

Why does Nigeria let foreign private equity firms and solar project "developer" make so much money?

This size of solar plant can be built with 1.0m USD per MegaWatt.

Wow,
1,750 mio USD / 1,125 MW = 1.555 mio USD/MW or 1,555 USD per Kilo Watt over a period of 20 years?

It's not bad business for the solar companies and banks who will finance the solar parks/farms.
I agree that >10 MegaWatt solar plants can be built with 1.0-1.1 mio. USD per MW.
A single MW solar plant is about 1.2 mio. USD (depending on the quality of solar modules).

Any information about the kWh tariff, they will get?

Is there any domestic content obligation for the solar components?

Ontario (Canada), South Africa and India had gradually introduced domestic content obligation of 10-20% and more.
It forced the solar manufacturers (steel/aluminium, inverter, solar panel) to open up factories attracting additional investments and creating high-value jobs, not only construction jobs.

Nigeria should do the same. Create a sustainable solar economy as well, not only construction and maintenance jobs.

@spyglaxx:
Do you have a voltmeter? Can you double check the voltage on the battery?
Can you tell us the voltage of the different states.

I guess a pro hair dryer alone draws 2000 Watts?

You need enough space on the roof for the amount of solar panels needed.
Let's take a moderate panel with 250 Watts(peak) poly which is 1,65m long and 1,0m wide. For 10.000 Watts(peak) you will need 40 panels.
And a single phase (electricity cable) should not go beyond to 4,6 kVA, so you will need a second phase for your salon.

May I ask what would you be willing to pay for electricity, if you were able to have light during business hours?

Currently, it's cheap, but on the other hand it is only available for a couple of hours. When businesses had light all the time, they could do more business and generate more money.

Hello,

here I found the graph of the number of cycles depending on the energy used.

This graph is valid for a special type of lead-acid battery, it's called "heavy-duty" plate, open valve lead-acid battery - similar to those that are used in folk lifters.

Example: if you use only 30% of the battery capacity, the battery's life is 4.000 cycles (at standard temperature 25°C).
if you use 50% of the battery capacity, then it's 2.500 cycles.

Lower quality, non-heavy-duty plate (not so thick), will have less cycles. As well as in hot temperature, the number of cycles is less.

I hope you get an idea, how to treat your battery, so it lasts longer.

sunny regards,

@ Cargoed: I am sorry, IF I insulted anyone. But I do not think that I have insulted anyone?!

I think, in general it is good that many people think of energy-efficiency before making a purchase of any electronic devices.

I would like to share my knowledge, solar experience of several years and access to some simulation software.
In the beginning, obviously I made not so good solar designs, but after implementing real-world applications over several years, I hope to share my lessons learned with the house.

Of course, there is a reason why there is a market segmentation.

And I do agree that it is not fair that many people need to work their butt off, just to have some basic comfort, when light is off,
whereas it's the government's task to provide for the basic infrastructure, including light. (But this is a political issue, and I do not want to get involved in that!)

I prefer suppliers who provide 2 or 5 years of warranty AND who do not disappear after making the purchase.
But this is everyone's decision.

sunny regards,
John

Before buying a battery, you need to check the data sheet as well - not only the name/type plate.
The 'Ah' value is always dependent on the period of discharge, e.g. c 5 (=5 hours), c 10 or c 20.
Sometimes vendors put high Ah numbers for c50 or even c100 (=100 hours) on the name/type plate.
The slower you discharge a battery, the more Ah you get.
But in real life people discharge the battery the same night, within 5 hours.

Let me search for a chart... I'll get back.

@anochusk08:
I agree, for big loads, different set up is required. I don't know the brand of the solar charge controller or the inverter.

But definitely, you should take the ambient temperature into consideration. Often tests for the name/type plate is done in a lab.

Let's say, the solar charge controller can manage up to 30 Amps, then I would run with -20% of Amps, e.g. max. 24 Amps.
If it is a quality product, then I wouldn't mind. But with low-budget products I would be careful. Otherwise you will burn it.

Beyond 40 Amps, load is connected directly to the battery, and an additional battery management product with a shunt is deployed.
At least in commercial applications. So that the state of battery is well monitored.

Oh, and don't forget to put breakers and the right fuses. With 40 Amps you could weld metal!

@obimind:
Obviously 'deep cycle' describes the purpose of the battery: typical applications are UPS (in a stable grid environment where there is always light) or fisher boat (normally the engines powers a generator when on sea), so there are only view failures per year. Normally current of discharge is high. Let's say, it is used for 15 minutes, when a genset kicks in in a UPS application. It shortens the life cycle anyway, but the number of cycles is little in this case. => not suitable for every day charging and discharging!

'Gel' battery describe the built of the battery. Normally gel is put in glass matt in VRLA (closed Valve Regulated Lead Acid) battery. It is for "slow" charging and discharging without producing too much gas. It is more "gentle" to the materials inside the battery.

In general, to boost life cycle you should charge or discharge over a long time period, like 10hours (=c 10) or better 20 hours (=c 20).
I will look for a chart and post it here. The faster you charge/discharge, the shorter the life cycle is.

What I have read here, many people charge during the day and discharge the same evening.

One more factor is the depth of discharge (DOD). A battery that is only discharged to 80% of its capacity has a much longer life than a battery with DOD=50%.

So I have the feeling that people undersize their battery capacity.

My recommendation: when you have the feeling you have the right battery capacity, simply double it, then you will be on the right side.

sunny regards,

ah, thanks! I call it the 'solar charge controller';-)

Back to your question:
Yes, for small off-grid solar installation, the solar charge controller will pass through all current.

See the pic. below of a low-cost Chinese product.

@blazeup: may I ask what is 'CC'? Do you have a drawing of your setup? Can you share with us?

Being a power operator must be a nightmare.

On/off/on/off...

no wonder the stress on the power equipment is intense.
Switches/breakers are worn out...

distributed, small and smart grids with solar photovoltaic and intelligent power management is the long term solution.

(Those who can afford A/C's, should install the equivalent amount of Watts of solar modules on their roofs...)

Here is a system with 2 x 270 Watts(p)

24 Volt DC system
Solar modules are connected in series -> higher voltage when cloudy.

15 Amp 100 Volt MPPT solar charger

12 x 40 Ah VRLA batteries 12 V; 6 banks at 24 V.

1,6 kVA single phase inverter to power 1000 W water pump, lights and power tools in the garden.

Battery management system with display.

So, a solar system consisting of four modules with 250 Watts(peak) each is 1 kWp.

Total solar energy production = Size of solar system in [kWp] * Specific energy production at the given location in [kWh/kWp*a]

1 kWp * 1.648 kWh/m2*a (Lagos) = 1.648 kWh total solar energy production per year (-> on the roof!)

Daily energy production on average = 1.648 kWh/a / 365 days = 4,5 kWh or 4.500 Watts Hour per day (-> on the roof)

Due to energy losses of solar charger and inverters the efficiency of direct usage (not stored) is approx. 80%.
4.500 Watts Hour * 80% = 3.600 Watts Hour.
If you store the energy into batteries there are losses while charging and discharging, you can feel the heat of the batteries.
Batteries in good conditions have a 90% efficiency. (4-5% for charging and 4-5% for discharging).

Let's say 1/3 is used directly = 1.200 Watts Hour during the day
and 2/3 is stored 2.400 Wh * 90% = 2.160 Watts Hour.
Total energy available = 3.360 Watts Hour (24h day with storage)

Of course, there are rainy/cloudy days.

Solar energy:
Do you live in the south or north? You need to consider your location as well.
Here is the insolation for Lagos on a monthly basis.
Total global insolation means the total energy of the sun that shines on a surface of one square meter (1x1m) during a year.
The metric is 'kilo (=thousand) Watts Hour per square meter and per year'.

This translates to a specific solar energy production per year. Specific to a given location, e.g. Lagos (= latitude & temperature).
The metric is: x kWh/kWp per year. This metric tells you how much solar energy you will get on a 1000 Watts(peak) solar installation on the roof.
This is used to compare the quality and efficiency of each solar installation at a give location and to compare the insolation between different locations.
This takes into consideration:
a) type of solar cells (mono- or polycristalline)
b) type of installation (rooftop, ground, partially shaded)
c) tilt/inclination of the solar modules or if it is on a single-axis/dual-axis tracker.

kWp = kilo Watt(peak) = at peak power; The value Wp or Watt(peak) is found on the name/type plate on the back of the module.
This value is measured under laboratory conditions with a flasher (1000 Watts/m2, 25°C, ambient air pressure) .
Since the solar cells are semiconductors, solar cells are less efficient when they get hot. With every degree above 25°C the solar module gets less efficient. It is called Power Temperature Coefficient in % per Kelvin, e.g. -0,30 % per Kelvin.

Here is a side note to all of you who would like to power a freezer and a fridge as well.

There is an additional way to store energy: instead of storing electricity into chemical compound in a battery, use thermal energy as well, because it is more efficient and cheaper.

Put one or several plastic bottles with salt water into the freezer. But leave some air, so the water has room to expand.
When you have light (and solar during the day), run the freezer. The frozen ice will "save" the energy and absorb the "heat" from the frozen food.
Or you can take the bottles into your fridge.

The amount of salt needs to be calculated properly in order to lower the freezing point under 0° C.

(Just for your general understanding: In Northern Europe, where you have ice and snow in winter, people use a mix of salt and sand to throw onto the streets. The salt lowers the freezing point, so the ice melts. But this only works for certain temperatures. If it's colder than, let's say, -10°C, then salt won't help.)

@mesoprogress: Thanks for sharing.
Do you have a solar project site in sight?

What could be the possible tariff/price per kWh for solar electricity, if power is available for 24/7?

I think an ideal location would be a fish & meat market with ice block makers? Or electronics market?
Or a new residential building area?

have a good day!

Scenario system setup:
PV-Modules: 2 pcs., 270 Watts(peak) each, polycristalline
Total PV: 540 Watts(peak)
Setup: 10° inclination

Battery storage: yes, let's assume "big enough" 2,5 kWh (in theory.)
System efficiency: 84% (loss is due to MPPT charger, inverter, cable loss, ambient temperature, heat of battery)

Estimated solar energy production: 735 kWh per year, i.e. 735 kWh / 365 days = 2,01 kWh per day.

If you use PWM charger, the production is less.

Good morning,

here are some results. For the calculation I took Lagos as the reference location.
Global insolation for Lagos is 1.648 kWh/m2 per year.
Min. temp. 20°C and max. temp. 34°C (this is important for the solar cell efficiency and energy production.)

Here is the wiring diagramm
(c) 2015

Here is a 2 x 270 Watts(peak) off-grid garden project to power a waterpump (1000 W) and handtools to work.
QCells (Made in Europe) in series.
Batteries VRLA from Fiamm (Italian) 12 x 40 Ah(c10) = 480 Ah
Inverter (Danish/German) 1,6 kVA
Charger (Danish/German) 100 Volt, 15 Ampere

My advice for sizing: if you have money, go for the worst weather scenario, so that you generate enough power on cloudy days.
If you're short on money, then go for the best weather scenario, so you don't waste surplus energy that you cannot store in your battery.
And never size your battery too small. The nameplate "200 Ah" is always dependant on the duration of discharge.

@1kinggy: May I ask, where you are located?
This is John, residing outside of Nigeria, but I am eager to learn the regional environment, i.e. climate conditions, solar insulation, and to understand the market needs. I have access to a solar insulation simulation software. I've been in the solar business for the past 9 years in Europe. Hopefully, I can give you some advice.
Do you have more data on your batteries?

My personal advice: get high-quality solar modules. A 12 years product warranty, or 25 years performance warranty is nothing, if the manufacturer/importer goes bankrupt, that happened to most European manufacturers by the way.
For my first commercial solar installation (28 kWp), I chose the "cheapest" module available from a brand manufacturer: 160 Watts(peak) Sharp, but for my 2nd solar installation (24 kWp) I took US Sunpower with 305 Watts(peak) per module. Now, in Europe I only sell QCells (German), LG (Korean) and BenQ (Taiwan) with Sunpower cells. The biggest problems we had are with small manufacturers who simply disappeared from the market.
Good modules have an annual degradation of less than 0,5%. Bad modules

regards,
John
p.s. this is my very first post on nairaland. Don't know how I landed here, but this is quite an interesting thread!