IKEA tea lights, at least 9. Take one old oven/grill shelf. Find 3 short lengths of wood, around 2" thick.
Lay these out in a triangle on the table/cooker top.
Light tealights and place in a circle inside the triangle.
Put oven shelf on top.
Boils a kettle in 20 minutes
i should have added LIL, that the tea lights is one of those ideas that is obvious when you hear it but i think not one some people would thnik to use, good post.
I got it from a girl on a moneysaving forum - I was so taken by it that I used one for weeks and drove the OH mad he had to apply half an hour in advance when he wated a cup of tea
I did something similar during the floods here, used a deep baking tray (one that you would cook a chicken in) put 5 tealights at one end and the same at the other then put cooling rack over it and cooked tinned food and boiled a camping kettle.