NOVELTY - Preparation of peat-based fuel balls (I), comprises using wet peat, having a moisture content of 80-95 wt.%, from a bog deposit as a natural raw material, converting the peat into ball-shaped or approximately ball-shaped units, drying the units until the remaining moisture content is maximum 12 wt.%, mixing the wet peat together with at least one moisture-absorbing, biological fibrous material having a lower moisture content than the moisture content of the wet peat and adding the moisture-absorbing fibrous material until the mixture of peat and fibrous material has a moisture of 50-75 wt.%.    USE - The moisture-absorbing, biological fibrous material is useful as an additive in wet peat for production of fuel balls (claimed). (I) is useful as fuel in ordinary wood-burning stoves, pellet stoves and industrial heating installations adapted to solid fuel. (I) is useful as a substitute and/or supplement for ordinary wood pellets.    ADVANTAGE - The method dehumidifies the wet peat by mixing the raw material with fibrous material, thus simple and cost efficient. The method avoids or substantially reduces the large dust problems and danger of ignition and fire that encumbers the known process for production of fuel pellets. The obtained fuel balls have a continuous, even and strong surface exhibiting a far greater structural integrity than that of cylindrical rod pellets. The fuel balls is easily fed from a feeding chamber and into a combustion furnace/stove as they self-roll due to their shape, thus does not require a feeding device, e.g. a feed screw, in order to feed the solid fuel into the furnace/stove, thus the furnace/stove using (I) has a simple and cheap construction than that of a pellet furnace/stove. (I) can be dried easily, due to their ball-shape, than the rod-shaped pellets, as the drying medium normally consists of air that flows more easily through a mass of balls than a mass of rod-shaped pellets.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for use of a moisture-absorbing, biological fibrous material as an additive in wet peat for production of fuel balls from a mixture of the materials, where the fibrous material acts as an integrity-enhancing reinforcement material in fuel balls.