A wood stove will burn seasoned hardwood in the most effective manner. It will combine long burn times with the least amount of ash.
A wood stove is significantly more efficient than an open fire. Stoves can run at an 85% efficiency compared to just 20% with an open fire, where over four fifths of the heat is lost up the chimney.
The best fuel to use is seasoned hardwood. For the best results this means dry wood with a moisture content below 20% that is well, but not too tightly, packed into the firebox. The more moisture there is in the wood, the more it will smoke and possibly cause tar to build up in the chimney. Not only that but it will produce less heat. Peat can be burned in turf or brick form, but the moisture content must be low. Household refuse will burn successfully but only if it is dry and fairly tightly packed. Never burn plastics.