To address the issue of climate change, the EU’s climate and energy framework has set targets to improve energy efficiency. Reducing greenhouse gas (GHG) emissions requires higher energy efficiency in the wood supply of forest industries. The aim of the study was to clarify the energy-efficiency baseline for wood-harvesting operations, define useful measures and follow up the total fuel consumption and resulting emissions.
The results indicated that wood-harvesting entrepreneurs have a positive attitude towards energy efficiency. The fuel consumption of wood-harvesting machines was the lowest for the final fellings, while in first thinnings, the consumption was highest per cubic metre harvested. The average cubic metre-based fuel consumption and GHG emissions in respect of wood harvesting were more than double in the first thinning compared to the final felling. Better allocation of harvesting machines could reduce fuel consumption and GHG emissions while improving work efficiency. Hour-based fuel consumption is most affected by machines’ engine power and wood-harvesting conditions of forest stands. Fuel consumption per cut cubic metre is affected by wood-harvesting conditions and machine units.
The calculated energy efficiency was highest in final fellings. A more significant factor than fuel consumption (input) is the amount of harvested wood (output) in the energy-efficiency equation. Energy efficiency can also be improved by operator education. Trucks which are used for harvesting-machine relocation have a significant impact on wood-harvesting operations' total fuel consumption and emissions. It is therefore essential to minimise the number of relocations and operational and resource planning should be developed. In the future, the examination of fuel consumption and GHG emissions should be extended to the entire wood-harvesting chain, including long-distance transportation and timber trade, and for example the effect of operator should be investigated in more detail.