Make yourself a portable oil burning lamp and stove...

Probably one of the cheapest fuels to burn besides wood would be oils.  They’re so easy to get and get cheap.  You can find olive oils, pomace oils, vegegatble oils and maybe even sunflower oils, in a pretty decent sized bottle. 

With an oil burning stove you can bring an extra few ounces of the oil of your choice with you and be good for a week.

I wanted a small, compact oil burning system that I could put the lid back on when finished using it and not have to worry about it spilling on me.

I’ve used this stove to heat up the inside of my tent on several occasions, when I needed that extra bit of warmth as well as to provide light; but mostly I use this stove for getting small amounts (1-2 cups) of water hot for coffee / brews or for heating up soups, stews and other canned goods.  I’ve cooked meals with this oil stove hundreds of times.  It’s not going to prepare a meal for a family, but it will work for the solo camper for certain things.