No power and you need a light source? This DIY candle from Instructables user The King of Random builds a candle from household staples: butter and toilet paper.
The project looks pretty easy, as you can see in the video above. You'll need a suitably sized piece of butter (cut a typical 250 gram block in half and keep the paper around it). To make the wick, cut a sheet of toilet paper and roll it. (The video recommends a quarter of a sheet but that's based on a smaller US butter "stick", so you may need to experiment a little.)
Dig a hole to place the wick using a toothpick and then insert it. When you're done, you have a candle that will actually burn for hours. Butter may not seem like a likely source for light, but it will do the trick.
Make a Butter Candle - Emergency Candle McGyver Style! [Instructables]