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

[SunEagle]

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.

Your math is correct except it will be hard to find an MPPT type charger at 5 amps. So you will probably use a PWM type which changes your watt hours per day to 36 x 4 x 2.0 = 288 Wh.

That increases you panel to 60 watts which is ok since finding a 50 watt panel would be hard to do. You also may not get the 5 hours per day of useful sunlight so you will need a bigger panel with less hours.

Battery size stays the same as well as the 5A charge controller. Although it might be hard to find an inverter of only 50 watts. You may need to go to 100 watts which could increase your battery size somewhat.

This is a bare bones system and has no room to enlarge in case your load increases beyond the 36 watts. You may want to go slightly bigger on panel wattage, battery Ah and charge controller Amps. Try increasing your needed wattage and see what that gets you in calculation. Then go and price the equipment. Spending a little more up front for a slightly bigger system may be worth your while but there is a break point on type of panel and CC once your calculations hit the need for a 200 watt panel.

[Wy_White_Wolf]

IMHO, You need to look into using 12V bulbs and something like Morningstars' sunlight controller.

Reasons are:

1) You need a timer on the system to turn it on/off. Forgetting to turn it off 1 night means you need leave it off the next night to makeup and give eveerything a chance to recharge.

2) Using a timer with AC bulbs gives you 2 options.
a) Installing an AC timer between the inverter and bulb. Doing this means you need to calculate the inverter draw on the batteries for the other 16 hours and add that into the calculations.
b) Installing a 12v timer between the batteries and inverter. Don't plan on the inverter lasting to long doing this as I have yet to find an inverter that likes to be started under load. You would still need to calculate in the timers draw on the system.

Just my 3 cents (inflation)

WWW

[Naptown]

IMHO, You need to look into using 12V bulbs and something like Morningstars' sunlight controller.

Reasons are:

1) You need a timer on the system to turn it on/off. Forgetting to turn it off 1 night means you need leave it off the next night to makeup and give eveerything a chance to recharge.

2) Using a timer with AC bulbs gives you 2 options.
a) Installing an AC timer between the inverter and bulb. Doing this means you need to calculate the inverter draw on the batteries for the other 16 hours and add that into the calculations.
b) Installing a 12v timer between the batteries and inverter. Don't plan on the inverter lasting to long doing this as I have yet to find an inverter that likes to be started under load. You would still need to calculate in the timers draw on the system.

Just my 3 cents (inflation)

WWW

Probably the best solution.
Funny how it takes a lot of posts to get all the information needed to get to a workable solution.