Solar lighting system in our school

[Mike90250]

How many 50w lamps will you be using.

get the math teacher at the school to help you.

# of lamps
50 w
# hours (12)

12 hr x 50w = 600wh x (number of lamps) That's how much power is burned in 1 night.

You need a battery that is 4x that number, to get long ( >5 years) life from it.

Your solar array needs to be at least 2 x ( 600wh x (number of lamps) ) you got earlier, sometimes 3x.

It's going to be expensive. Plugging in the lights will only cost you 10 cents a night, per light, solar will cost you over a dollar per night, per light.

[pastmaster02]

Hello! I've just recently joined Solar Panel Talk forums. I'm kinda new here. I just came to ask for some advice and help about our planned project "solar lighting system" for our school. Our project is about making an outdoor lighting system that runs from solar energy and they will only be turned on at around 6PM up to 6AM in the morning the next day so that's 12 hours of continuous lighting. We are planning to provide about 50 watts of LED lamps at 12V DC for the area (it's actually a catwalk). We are also planning to buy a solar panel array with a capacity of 100 watts peak (*12V). And to provide the storage for our energy, we are also planning on buying a 12V 100 amp-hr deep cycle battery with a 30 amp solar charge controller. Now my question is: are these components enough to make our project work?

I've imagined the connection to be something like this: solar panel array > solar charge controller > battery > LED lights

I've got more questions:
1. How long can a full charged 12V 100 Ah deep cycle battery provide power to our 12V 50 watt LED?
2. How long does it take to charge up a 12V 100 Ah battery if our solar panel array provides 100 watts peak of power at 7 sun hours?
3. Does increasing the depth of discharge of our battery affect the duration of the "on" time of our LED lamps?
4. What is the advisable depth of discharge for a 100 Ah 12V deep cycle battery?

* I'm not sure if the voltage output of the array is 12V. Some say that it can be up to 17 V. How can I determine what voltage our array provides?


Can someone teach me how to calculate the information needed to make our project successful? These are our available materials (they're kinda fixed because we are low on budget hehe):

50 watts 12V DC LED lamps (turned on for 12 hours)
100 watts peak solar panel arrays
100 Ah 12 V deep cycle battery
30 amp solar charge controller (based on the info above, can we reduce the rating of this charger? we really need to budget out money wisely)

Thank you.