Solar Panel Setup for 1 room

[Nazeer Khan]

Hi everyone, i m from Pakistan where 10 to 12 hours of electricity is provided by government . I want to setup a off-grid solar setup for my room which has 1 fan, 3 savers, 1 referigerator and a LCD TV, 100watt, 100watt, 250 watt and 100 watt respectively the wattage used by electrical items. All items are 220v AC.

I have Tristart 45amp pwm charge controler. thats it.

Anyone advice me how many panels, batteries and inverters will be required for 24 hours setup. By the way, we have 8 hours of sunshine in winter and 10 hours of sunshine in summer, still hot today.

hope, someone would help me for solar setup.

Thank you

[Mike90250]

That is going to take quite a large battery, as you never know when the power cut comes, day or night.

I'm counting 550W, and not sure if that includes the fridge, TV .....

550W x 24hr = 13,200 watt hours consumed, your battery needs to be 3x that size to have a long 5 year lifetime.

13200 x 3 = 39,600 watt hour battery @ 48V would be 825ah That's really large, and you will not likely be able to manage that.

Size wise, that would be 33 car batteries, 1000ah each.

If you can refine the power consumption more, that would help.

[lkruper]

That is going to take quite a large battery, as you never know when the power cut comes, day or night.

I'm counting 550W, and not sure if that includes the fridge, TV .....

550W x 24hr = 13,200 watt hours consumed, your battery needs to be 3x that size to have a long 5 year lifetime.

13200 x 3 = 39,600 watt hour battery @ 48V would be 825ah That's really large, and you will not likely be able to manage that.

Size wise, that would be 33 car batteries, 1000ah each.i

If you can refine the power consumption more, that would help.

How about grid charger and batteries to handle 50% of one day's power needs and no solar since a certain amount of regular power is guaranteed?

[d_1d]

How about grid charger and batteries to handle 50% of one day's power needs and no solar since a certain amount of regular power is guaranteed?

That sounds like the right approach.

Also, simply summing the watt ratings of those devices will overstate how much energy (battery size) you need to store. It's likely much less. How often does the fridge run, for example? The TV? Divide those watt ratings by the fraction of time it's on per day, and sum those up:
e.g. - TV: on 10% of the day, so TV_WATTS * 0.10

You'd need batteries, chargers, an inverter, and maybe a connect/disconnect switch.

Should be relatively straightforward!

[lkruper]

That sounds like the right approach.

Also, simply summing the watt ratings of those devices will overstate how much energy (battery size) you need to store. It's likely much less. How often does the fridge run, for example? The TV? Divide those watt ratings by the fraction of time it's on per day, and sum those up:
e.g. - TV: on 10% of the day, so TV_WATTS * 0.10

You'd need batteries, chargers, an inverter, and maybe a connect/disconnect switch.

Should be relatively straightforward!

Good catch. Also I think getting an inverter/charger with transfer switch would smoothly take care of switching from grid to battery power and charging the batteries.

[Nazeer Khan]

That is going to take quite a large battery, as you never know when the power cut comes, day or night.

I'm counting 550W, and not sure if that includes the fridge, TV .....

550W x 24hr = 13,200 watt hours consumed, your battery needs to be 3x that size to have a long 5 year lifetime.

13200 x 3 = 39,600 watt hour battery @ 48V would be 825ah That's really large, and you will not likely be able to manage that.

Size wise, that would be 33 car batteries, 1000ah each.

If you can refine the power consumption more, that would help.

OK, I understand, we refine it like, TV for 5 hours, Fridge for 10 hours, Fan for 15 hours, lights for 6 hours. Hope this help to figure out the setup.

[Mike90250]

put your own numbers in,

TV 150w x 5 hours =
Fridge _ _ w x 10 hours =
Fan 100w x 15 hours =
Lights 150w x 6 hours =

When you have the watt hours totaled up, then follow my example of wh x 3 = battery watt hours divide by 48V = ah of battery.

[Nazeer Khan]

put your own numbers in,

TV 150w x 5 hours =
Fridge _ _ w x 10 hours =
Fan 100w x 15 hours =
Lights 150w x 6 hours =

When you have the watt hours totaled up, then follow my example of wh x 3 = battery watt hours divide by 48V = ah of battery.

Thank you mike, I get 343 ah Battery following your calculation. It seems, I cant afford the setup.

One question if you could spare a time for this would be appreciated.
I know, battery is must with solar system but I dont know why it is necessary although the Charge controller regulate the voltage, I am talking about for the day time.

Thanks in advance Mike.

[lkruper]

Thank you mike, I get 343 ah Battery following your calculation. It seems, I cant afford the setup.

One question if you could spare a time for this would be appreciated.
I know, battery is must with solar system but I dont know why it is necessary although the Charge controller regulate the voltage, I am talking about for the day time.

Thanks in advance Mike.

There are a couple of things you could do. First, though, what is your budget?

You say your TV is 150w. If you got that from the nameplate documentation, that may not be how much your TV uses. Also, TVs are generally configurable with an option for Eco mode or power-saving mode. Then if you turn down the brightness you can save even more. My TV was about 100w, then 60w in ECO mode and then 28w with backlighting turned way down.

Then there are the lights. Are you using LED lights? an LED light that has the same brightness as a 60w incandescent light draws only about 10w. Then there is the fan. They sell fans that run on batteries and DC power.

So you cannot afford to buy 343 AH which is 3X your daily Wh? Does that mean you cannot have any backup at all? What if you just get 1X your daily AH usage? That would be 114. Then instead of buying solar panels, get a battery charger. If you get 10-12 hours of power a day, you have plenty of time to charge your batteries. When the power goes out, you only need enough capacity for 1/2 a day, correct? So 1X your Wh is 24 hours, and 1/2 is 12 hours. If you take your battery down to 50%, 1X or 114AH works. That is one Marine battery.

Also, it is quite possible that your power usage requirement either is actually lower because you have not measured it, or can be even lower through conservation.

Another example besides the TV is a refrigerator. The manufacturer may say it takes 500w. But the compressor does not run all the time. It might only run 1/3 of the time. But the maker of the refrigerator gives the maximum draw of the fridge.

Don't give up yet. But also, research first and buy later.

[Nazeer Khan]

There are a couple of things you could do. First, though, what is your budget?

You say your TV is 150w. If you got that from the nameplate documentation, that may not be how much your TV uses. Also, TVs are generally configurable with an option for Eco mode or power-saving mode. Then if you turn down the brightness you can save even more. My TV was about 100w, then 60w in ECO mode and then 28w with backlighting turned way down.

Then there are the lights. Are you using LED lights? an LED light that has the same brightness as a 60w incandescent light draws only about 10w. Then there is the fan. They sell fans that run on batteries and DC power.

So you cannot afford to buy 343 AH which is 3X your daily Wh? Does that mean you cannot have any backup at all? What if you just get 1X your daily AH usage? That would be 114. Then instead of buying solar panels, get a battery charger. If you get 10-12 hours of power a day, you have plenty of time to charge your batteries. When the power goes out, you only need enough capacity for 1/2 a day, correct? So 1X your Wh is 24 hours, and 1/2 is 12 hours. If you take your battery down to 50%, 1X or 114AH works. That is one Marine battery.

Also, it is quite possible that your power usage requirement either is actually lower because you have not measured it, or can be even lower through conservation.

Another example besides the TV is a refrigerator. The manufacturer may say it takes 500w. But the compressor does not run all the time. It might only run 1/3 of the time. But the maker of the refrigerator gives the maximum draw of the fridge.

Don't give up yet. But also, research first and buy later.

Many many Thanks for all the replies from experts like you and others. I still hope and I will re-calculate my consumption by replacing some AC equipment to DC.
Well, thank you for your precious advices.

Nazeer Khan

[Mike90250]

AC watts are the same drain on a battery as DC watts. You may save a few % by not going through an inverter, but the large portion of the consumed power will be very much the same.

[SunEagle]

Thank you mike, I get 343 ah Battery following your calculation. It seems, I cant afford the setup.

One question if you could spare a time for this would be appreciated.
I know, battery is must with solar system but I dont know why it is necessary although the Charge controller regulate the voltage, I am talking about for the day time.

Thanks in advance Mike.

You will need some type of energy storage or secondary power system to run the electrical loads you listed for more than 5 hours a day.

Even though the sun is shining it does not produce enough energy to power the solar panels to their wattage rating. So most of those loads will not even turn on.

Also during cloudy or rainy days the sun will not produce any energy so again you need another power source like batteries or generator.

[ShineOn]

I think with something like this you need to focus on the appliances that you really need to power. I mean forget the tv and the lights because you can use your daily allowance for these things. Instead just power the fridge to stop your food going off.