Some kind of SHTF/TEOTWAWKI situation has happened, society has broken down, and the power has finally gone off.
Or, some kind of natural disaster has happened, power has been cut off and my not be restored for several days to several weeks. After Hurricane Rita, my family and I spent 18 days without power. So power outages are not reserved for a long term SHTF/teotwawki situation.
My light preps are kerosene, hand crank lights, solar lights and your regular LED lights. Each light source has their own advantages and disadvantages.
For over a hundred years kerosene lanterns have been used by mankind in lanterns. Kerosene stores somewhat well, depending on the type of kerosene that is being stored and what the kerosene is going to be used for. Overtime bacteria develops and feeds off the fossil fuel; when this happens the fuel will start to gel.
To get the most out of your kerosene, you may want to consider treating it with a type of diesel fuel treatment that prevents the growth of bacteria.
Kerosene lanterns pose a fire risk, especially around small children.
When my family has to use a kerosene lantern, we place the lantern in a bathroom so the light can reflect off of a mirror, and several inches away from the edge of the counter top.
When picking a lantern, be sure to take the size of the reservoir into consideration. The larger the reservoir, the longer the lantern can operate.
If kerosene is going to be included in your long term SHTF survival plan, keep in mind your kerosene is going to run out sooner-or-later.