24 hours is not that long !
I would consider long term emergency lighting to be for a month a more, post large hurricane, EMP event, or other large disaster.

A standard stock D cell Maglight runs 12 hours on a set of batteries, one set of spares gives 24 hours.
A flourescent lantern runs about 24 hours on one set of D cells.
An LED lantern for several days.
For lower level or localised lighting there are numerous LED flashlights that give run times longer than 24 hours on a single cell.

For TRUE long term emergency lighting I have a few hundred alkaline cells, a few dozen lithium cells, a 12 volt system with PV charging, a few hundred candles, and ample kerosene for several thousand hours light.
Candles and oil lamps are ideal for long term lighting but can be a fire risk. Consider installing hooks in the ceiling, or wall brackets, from which lamps can be hung.

The true doomer also keeps stocks of sulphuric acid and lead sheet in order to make lead acid batteries.

I'm with Dweste on this. Do most of your work in the daylight.

During multiple days without power I always carry a small flashlight on my person but oil lanterns and candles (in lantern like enclosures) are hard to beat for general lighting. A few tea-light candles strategically placed will provide light all evening (4-5 hours). You can buy 100 of them for about $5 and each box of 100 is roughly 12"x12"x2".

I'm in the midst of converting my incandescent flashlights to LED either by phasing them out or using conversions. I think I'm also going to stop by AAA and CR123 lights and standardise on AA and D lights. I've got plenty of lights that run on AAA and CR123 and its just much easier to get AA and D batts once you're out of the city.

I've got a few Nokero solar powered lights on order just to check them out.

I with dweste and hikermor too. Get my stuff done during daylight and stretch out the life of your lights. When I'm out in the interior in Borneo, the villages here are quite dark at night, maybe a light/candle/lantern or two per household and even then not for long.

Kerosene lanterns have a lot of issues, but they're cheap and fuel is cheap over here in Borneo.

Tealights are great and I usually have a few 100 count bags in the house and one bag in the car.
Oil lamps and plenty of fuel on hand as well.
I also have 3 NightStar shake flashlights. These work for approx. 20-25 mins. for 30 secs of shaking. I got the transparent ones and these can be placed on end (LED side down) on a white sheet of paper or similar on the table and thus used will light a room same way a candle would. The light is reflected back by the white surface into and through the translucent flashlight body and lights the room. Also have two led infinity lights by Gerber which will work for 40-something hours on one AA battery.
ATB
Pharaoh.

Not listed are low-end lights, weaponlights, or handheld flashlights that sit next to a pistol in a safe.


* Two 3-D cell MagLEDs. Bright, but unregulated. 11 hour runtime (with significantly reduced output after the first few hours).

* Quark 123^2 S2. Medium (19 ANSI* lumens) 20 hour runtime.

* Quark 123^2 R5 Ti LE. Medium (22 OTF** lumens) 20 hour runtime.

* Quark 123^2 R2 Tactical. Medium (18 OTF lumens) 20 hour runtime.

* Quark 123 S2. Medium (19 ANSI lumens) 13 hour runtime.

* Quark 123 R5. Medium (22 OTF lumens) 13 hour runtime.

* Quark 123 R2. With a Prism and headband on it to make it my primary headlamp (this gizmo will work with any Quark other than the MiNi). Medium (18 OTF lumens) 13 hour runtime.

* Preon 2 S2 Ti. Medium (26 OTF lumens) 6 hour*** runtime. I have the Preon 1 body for it, which on Medium does 13 OTF lumens for 6 hours.

* IlluminaTi R5. Medium (30 emitter lumens) for 4+ hours.

* Preon ReVO SS R2. Medium (19.8 OTF lumens) 5.7 hour runtime.

* Preon ReVO R2. Medium (19.8 OTF lumens) 5.7 hour runtime.

* Fenix P2D Q5. Medium (55 emitter lumens) 5.5 hour runtime. I also have the L1D body, which gives 53 emitter lumens for 5 hours.


None of these will work without batteries, of course. All the flashlights listed above have batteries in them and most are at 80+% charge. My BOB contains 12 new Titanium Innovations CR123A batteries in a nice plastic case, and 12 new Energizer Ultimate Lithiums (again in a nice plastic case) right next to it. There are also 8 Energizer Lithium AAAs in the original packaging.

My battery drawer at home duplicates the plastic case of CR123A batteries, five more CR123As that didn't fit in the case, roughly 40 Energizer Lithium AAs and 12 AAAs. I have a box of 12 Duracell D batteries as well.

None of this counts my rechargeable AAs, 14500s, or various other flashlights stashed here and there. It's distinctly possible that I have gone overboard in this particular area of preparation.


[* - ANSI lumens are like OTF lumens, but measured after the light has a chance to warm up and therefore run with less efficiency. Probably the most useful lumens measurement. The Quark S2 is brighter than the Quark R5.]

[** - OTF == Out The Front. The actual lumens emitted as the light is turned on (and not warmed up). Most flashlight manufacturers use emitter lumens, which has the effect of overstating the usable lumens figure by roughly 30%.]

[*** - I feed my AA and AAA flashlights Engergizer Ultimate Lithiums, so my runtimes will be 20+% better than the manufacturer estimates on alkalines.]

I started to write out a lengthy post on this, but ended up just putting it on my blog instead:

http://flsgear.wordpress.com/2011/02/12/long-term-lighting-in-teowatki/

For long term lighting during wintertime I will be using a Bullfinch 1616 Handilight Lantern. It will give me approx 250 hrs continuous use at an equivalent 100W incandescent light output (150W @96gms/hr) i.e. around 1250-1500 Lumen when using a standard 15Kg LPG bottle. So if in use for 6 hrs per day would give me around 6 weeks use operationally on a single LPG bottle.

http://www.gasproducts.co.uk/acatalog/Bullfinch_1616_Handilight_Gas_Lantern.html

It also has the other benefit of providing some supplementary heat output as well during long 16 hr winter nights. During summertime it doesn't really get dark (sunset around 11pm and rises around 5am) and a solar PV battery system/LED lighting will easily cope with any outages.

Like Eric above, I have so many flashlights I am not sure which I would use first- and as much as I want to buy American, there has never been a better selection of LED flashlights for sale, batteries included, down at the HD.
I keep handing them off to my adult kids saying ".. here, put this in your car, put this on your electrical panel, etc."
I also have tea light candles, Y2K vintage 500 hour candles, D battery flashlights and a battery supply shelf to swap out at least 3 replenishments... before I even go out to my garage and break into the Coleman lanterns.
And now that I see the "old School" lantern from Leamans above, I have flagged that for my next "gift to self" event.

Why is there any >24hr requirement?

For years I used a cheap incandescent, battery munching, flashlight with 'heavy duty', low capacity chloride, cells and made it work. Even for a week out camping I seldom used more than one set of batteries. Most things can be done in the dark. When the sun goes down you park it and sleep. Total artificial light use each day was a few minutes. Mostly digging in backpacks and finding stuff I dropped. Most tasks can be done by moon/starlight and by feel.

This isn't without precedent. Historic anthropologists estimate that most farmers in the late 1700s were getting ten or more hours of sleep each night. More in winter; less in summer. This was motivated by the cost of lighting. Candles and oil were expensive. Tallow and rush lighting, the low cost alternatives, gave very poor light, smoked, smelled and were otherwise problematic.

Exactly what is the light needed for? How much light, duration and intensity, is really needed?

Back in the late 60s flashlights ate batteries, didn't produce much light by today's standards, and the lights were bulky and relatively expensive. Many a Boyscout troop had one flashlight for every second or third kid and but one set of batteries per light. You didn't use it when it wasn't needed, and you didn't leave it on for long.

About the only areas that might need extended lighting through the night would be something along the lines of a command center or casualty collection site. But both of those are pretty much beyond the scope of what an individual, or even a small group, needs to worry about.

Given this sort of need oil/kerosene lamps and slow-burn candles are suitable for low-area/ambient lighting. The advantage of oil and candles are that they are simple, reliable, and the energy sources store quite well.

There are several small LED lights that use larger batteries, in one case a standard 9v stack, and they can work well. LEDs are quite easy to rig into a wide variety of batteries so they are fairly easy to rig for anyone handy with basic electricity.

For higher intensity lighting, such as task lighting for reading and medical procedures, propane and white gas mantle lanterns are quite good. These burn through a night on low but need refilling on high.