Yesterday's power outage brought to mind a small experiment we did last week. Just how long, we wondered, will a gallon of kerosene service an oil lamp? The answer has bearing on how much kerosene we should store for our non-electric lighting needs.
Kerosene lamps are our preferred non-electric lighting option. We have flashlights and rechargeable batteries, of course, but those aren't practical for working indoors around the house. We also have some mantle lanterns (Coleman and Aladdins), but for everyday usage, we figure we'll use kerosene lamps.
Some people are affected by the smell of kerosene, but the smell can be minimized if the lamp is lit and blown out while outside or in the garage. Nonetheless there is a detectable odor while a lamp is burning. It doesn't bother us at all, but it may bother others, so if that's the case, then pure lamp oil (though it's more expensive) might be the better option.
But how much kerosene should we store? How long would a gallon of kerosene last us, if we were using kerosene lamps on an exclusive basis? We didn't know.
So we decided to run a small test. We took an empty oil lamp with a standard 3/4" cotton wick...
...and filled it brim-full of kerosene.
Then we poured it back into measuring cups to measure how much this particular lamp holds. Answer: 2.5 cups.
Then we lit the lamp and just let it burn. Day...
...and night. The only time it was blown out was when we were in bed.
We marked down start and stopping times.
Finally the kerosene burned down low enough that I was concerned the wick would start to burn if I didn't blow it out.
The results of this admittedly unscientific experiment were as follows. 2.5 cups of kerosene gave us 33 hours' worth of light. This means there is 211.2 hours of light (for one lamp) per gallon of kerosene. If we keep a lamp lit for eight hours a day, this gives us 26.4 days of light per gallon of kerosene.
Now of course the amount of time lamps will be lit will vary. Needless to say if we're without power, we'll be timing our sleep cycles to the pattern of sunrise and sunset more than we do now. But nonetheless in winter, when we have fifteen hours of darkness at the winter solstice, we're going to need a light source for longer than in the short summer nights. Eight hours per day of lamp time during the winter is not unrealistic.
Keep in mind this is for ONE lamp. If you've ever read the Laura Ingalls Wilder books, you'll know the family of six always gathered around the table to the light of ONE oil lamp. People didn't light three or four or five lamps -- it was considered wasteful and unnecessary. In pre-electric days, people didn't fight the darkness as we do now. They accepted it. They made do with ONE oil lamp.
Should the power grid ever go down for a prolonged period of time, people will have to re-adjust to a darker world. Based on the above calculations, if we wanted to keep four lamps running at the same time, one gallon of kerosene will only last us a bit over six days. But if we made do with just one lamp, a gallon will last just under a month (during winter months when the days are shorter). Twelve gallons will comfortably last a year (remember, this is for ONE lamp). Something to keep in mind while sonsidering your lighting needs.
Estimates for the shelf life of K1 kerosene vary, but the consensus seems to be anywhere from one to five years, depending on how well it's protected from moisture (apparently kerosene is prone to water condensation inside containers). However anecdotal evidence suggests that kerosene may store for over twenty years without compromising its usability.
This is where I should probably insert the obligatory safety warnings. Kerosene lamps are prone to getting knocked over by children, wagging dog tails, clumsy moments, and other mishaps. You need to plan accordingly. When we lived in Oregon and the girls were very young, Don installed little open-topped wall boxes at various places around the house into which an oil lamp could comfortably fit with no danger of anything knocking it over. A mirrored reflector behind the globe also amplifies the light. Should we ever need to resort to oil lamps full-time, we will probably do the same thing.
As I see it, kerosene is a multi-use fuel that's stable, relatively safe, and fairly inexpensive. Frankly I think it's perfect prepper fuel and would make an excellent trade item in addition to personal use.
Besides... lamps are pretty.