How to make a solar system for my 2 light bulb (18W) each?

[Jeffych]

Hi. I'm totally new in Solar.
Would like to know how can I design the system for my 2pcs of 18W light bulb (AC) which operating for 8 hours a day (fr 7pm to 3am)? Thx.

[Naptown]

Go to the battery design link in my signature and fill out the calculator

[Jeffych]

Go to the battery design link in my signature and fill out the calculator

Thank you for your replied. Unfortunately I still not able to access it yet as I have 0 point in this forum at the moment. How can I do?

[SunEagle]

Thank you for your replied. Unfortunately I still not able to access it yet as I have 0 point in this forum at the moment. How can I do?

You can find that post by first going to the main Forum page. Look for the section called "Off grid solar" then click on the first post called "Off grid electrical systems". The third "sticky" post is called the "Solar Off Grid Battery Design". That is where you will find the information that Naptown mentioned.

[Jeffych]

You can find that post by first going to the main Forum page. Look for the section called "Off grid solar" then click on the first post called "Off grid electrical systems". The third "sticky" post is called the "Solar Off Grid Battery Design". That is where you will find the information that Naptown mentioned.

Thank you.
For my case..
18W x 2pcs = 36W
Watt per day = 36W x 8hrs (operating hr) = 288Wh
Multiply by factor 1.5, 288Wh x 1.5 = 432Wh

Assuming the total sun hour I hv is 4.5 a day..
Solar panel suitable for me is 432Wh ÷ 4.5h =96Wp which is ~100Wp

For the battery, 288Wh x 5days ÷ 24V = 60Ah
For Charge Controller, 100Wp ÷ 24V = 4.16A which is ~5A

Is it my calculation correct?
How about the inverter? As my load is in AC mode. Is there any calculation for it?

Sorry, as I really new in this field.. really hope that you can help up. Thanks.

[Naptown]

If that is all you plan to run get somewhere around a 100W inverter.

[Jeffych]

If that is all you plan to run get somewhere around a 100W inverter.

Thank you Naptown.

[inetdog]

Hi. I'm totally new in Solar.
Would like to know how can I design the system for my 2pcs of 18W light bulb (AC) which operating for 8 hours a day (fr 7pm to 3am)? Thx.

Are the light bulbs incandescent, fluorescent or LED? You might be able to save money overall on your system by using more efficient light sources and smaller batteries and panels.

[Jeffych]

Are the light bulbs incandescent, fluorescent or LED? You might be able to save money overall on your system by using more efficient light sources and smaller batteries and panels.

Is a normal bulb as we need to use it for some special application.
By the way, what is the estimated cost for 100Wp solar panel & 60Ah battery in the market currently?
And the inverter must be in Pure Sine wave?

[Naptown]

incandescent bulbs will not require a pure sine wave inverter modified is OK.
But a question that does arise if this is for for a particular application how critical is light output and the tolerance.

[Jeffych]

incandescent bulbs will not require a pure sine wave inverter modified is OK.
But a question that does arise if this is for for a particular application how critical is light output and the tolerance.

Noted. Will test it out & see.
By the way, I did a calculation if I use 2pcs of 5W LED bulb, I only need 30Wp Solar Panel & the charge controller is about 1A.

[Shockah]

Noted. Will test it out & see.
By the way, I did a calculation if I use 2pcs of 5W LED bulb, I only need 30Wp Solar Panel & the charge controller is about 1A.

Why not 12 volt LEDs? ...
Eliminates the need of an inverter.

[Jeffych]

Why not 12 volt LEDs? ...
Eliminates the need of an inverter.

Noted. Thanks.

[Shockah]

Is a normal bulb as we need to use it for some special application.

Are you stating you need a bulb for a special application? If so, what is the application?

Otherwise, If you need a simple dusk-to-dawn lamp, there are several designs available.

Choice would depend on how bright you need it and budget.

[Jeffych]

Are you stating you need a bulb for a special application? If so, what is the application?

Otherwise, If you need a simple dusk-to-dawn lamp, there are several designs available.

Choice would depend on how bright you need it and budget.

I'm using the normal bulb to attract insects during nite time for my biological project.
I tried to use the LED bulb in my research before, but it seem like the results is not so good. That's why normal bulb is needed.

By the way, I try to recalculate it again as the operation hours reduce from 8hours to 4hours as below,

18W bulb x 2pcs = 36W
Operating hour per day = 4 hours
Watt per day = 36W x 4hours x 1.5 (factor) = 216Wh

Assuming the total sun hour = 5hrs a day
Solar Panel I need = 216Wh / 5hrs = 43.2Wp which is ~50Wp

SLA Battery,
36W x 4hours x 5days ÷ 12V = 60AH

Charge Controller,
50Wp ÷ 12V = 4.16Amp which is ~5A

Is my calculation correct?
For the inverter, as the Solar panel is 50Wp, I choose 50W Inverter. Is it correct?

Please input me with your comments. Thank you.