How do i cost-effectively use solar energy to provide light at night?
Question:
Answer:
You need the wattage of the bulb to determine the draw, then a solar charger big enough to replace the power used.
Ok...let's make some guesses and assumptions.
A 12v DC flourescent that puts out as many lumens as a 60W will draw about 15watts.
Watts / Volts= Amps, so 15/12=1.25 amps.
Ok...now the battery is not so much the problem, because a typical deep cycle battery, if fully charged will give you that 1.25 amps long enough to go a couple full nights without sunshine during the day.
The problem is the solar charger...you need someting big enough to replace the 1.25 amps you are drawing, plus something for loss of efficiency.
Here is an example of an available product that might fit your needs. http://store.sundancesolar.com/10watsols...
This panel will give you 18.7V at .62amps, so in rough numbers...you would get one hour of light run-time for every 2 hours of solar charge time.
You can get some pretty nice "starter" units that have battery; chargers and inverters included...this system to less than $400, and you could live like royalty...in Sierra Leone, anyway.
http://store.sundancesolar.com/20wadosoe...
I'm actually in the (very) preliminary planning of doing something like that for my house. My plan is to get a special (I'm guessing it would be a different one from conventional) battery in which it'll store the power and then flip the switch once it gets dark and just use it from that for the night (and temporarily disconnect the conventional power until the morning). I think this'll be quite complicated so I'll probably get an old computer to handle this function. Hope that helps.
To many variables to answer this question. Mostly depends on the efficiency of the system you install
saving on accu baterry
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