Fuel from bogs (4)
I believe the answer is:
peat
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">fuel from bogs</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for peat that I've seen before include "Saturated and compressed vegetable matter, used as fuel when dried out" , "Bog material" , "Tape around turf" , "Some got energy from this" , "Tape (anag.)" .)