In Slovenia, wood chips are used in most common way for heat production in heating stations; investments to build individual heat stations are too expensive. We analysed different systems for wood chips production, mainly as regard capacity and electricity consumption. To produce wood chips Lindner T650/250 chipper and 2 different wood species, the spruce tree (Picea abies L.) and the beech tree (Fagus sylvatica L.) were selected. The consumption of energy used for this process was analysed. The beech wood consumed 50 % more of electrical energy than spruce wood. The consumption was also related to the dimensions of wood chips.