Oil Lamp compared to batteries

[lkruper]

So why would you use 60 watt incandescent lighting on a battery lighting system? Incandescent has its place, but not for what you want.

You want T5, CFL, or LED. Yes it is a bit expensive, but a lot less expensive than the panels and batteries required to run equivalent incandescent lighting.

I was adding my note while you were replying. I had just read the other thread. And they last 25000 hours which is negligible for $28.

[Sunking]

So why would you use 60 watt incandescent lighting on a battery lighting system? Incandescent has its place, but not for what you want.

You want T5, CFL, or LED. Yes it is a bit expensive, but a lot less expensive than the panels and batteries required to run equivalent incandescent lighting.

Second point why 12 volts?

[lkruper]

I am in the process of trying to figure out my minimum power requirements for my cabin if the grid fails during an emergency. I have been reading posts about people reducing their needs by using led lighting, etc. However a quick calculation of the power needed to keep a 60w light bulb on for 8 hours per night was "illuminating." Please check my numbers as I am not yet a solar fanatic! I am only factoring in the cost of the batteries, not everything else.

• 60 watt light for 8 hours/day
• 60 * 8 = 480 w
• 480 * 5 (5 day autonomy) = 2400
• Inverter inefficiency @ 90% = 2640
• 2640 / 12 = 220 ah battery needed

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2 T105 = $280 (I have not looked for best prices yet)

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Lifetime of battery based on warranty. Could be more or less.
2 years = $140/year = 0.38 / day

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Cost of operating oil lamp.

1/2 oz per hour

Walmart cost of oil = 64 oz for $5.97 = 0.09 / oz * 4 = 0.36 / day

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So I come up with a little bit less cost with an oil lamp. One could burn cooking oil for free.
Also, a case of this oil would add up to quite a bit of autonomy. For my purposes, only
using off-grid for emergencies this makes sense as I already have 8-10 oil lamps in my cabin
and a bottle of oil. I don't think it would be much fun to live like this every day.


Without 5 day autonomy, the batteries come out way on top. How many ppl really subscribe
to 5 day autonomy in practice?


### edit ###############################################
After looking at another recent post it occurred to me that a 60w equivalent led takes
much less than 60w as a 50w equivalent was taking 8 w.
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Can lower the price of lamp burning by using kerosene... $4.00 / gal at the pump if you
can find it.
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