Spannmål till energi

The use of cereals and other agricultural crops for energy purposes and the increased demand for food world-wide have increased cereal prices. However since energy prices have also increased, it can still be profitable to use cereals for energy production. To date, the cereals used for bioenergy have usually been grown in the same way as food and feed cereals, but there is scope to tailor the cultivation system to the end product. The overall objective of this project was to improve the profitability of cereal cultivation for energy purposes. Changes to the cultivation system in terms of e.g. choice of crop and cultivar, strategies for fertilisation and crop protection and transport/handling of cereals for bioethanol production or combustion were studied. Timeliness costs associated with bioenergy cereals were also examined. The financial impact of changes in the cultivation system for bioenergy cereals was then examined for three typical farms, located in the provinces of Skåne, Östergötland and Uppland. Based on the results obtained, concrete guidelines for farmers were formulated. The average arable area of the typical farms was 203 ha, the farms had a seven-year crop rotation and for all locations winter wheat was the dominant crop but triticale and oats were also included. Two cultivation systems, Traditional and Energy, were examined. In the Energy cultivation system, the winter wheat and triticale were used for bioethanol production in an ethanol plant located in Norrköping (Östergötland), while the oats were used for combustion in plants close to the typical farms. The results showed that cultivation of bioenergy cereals did not differ greatly from cultivation of food/feed cereals. However, when cultivating cereals for bioethanol production it is important to adapt the nitrogen fertilisation strategy to achieve high starch content together with high yields of the specific cultivar grown. The most important change in the Energy system proved to be decreasing the nitrogen fertiliser dose to winter wheat for bioethanol production compared with food winter wheat, by 25 kg per ha and year overall for the typical farms. Yield then decreased by 200 kg per ha. There are currently no cereal cultivars developed specifically for combustion, but plant breeders should work towards producing cultivars that combine high yield with high energy content per kg dry matter. The economic analyses of the typical farms showed that the Traditional system gave higher profits than the Energy system in Uppland and Skåne, but the systems were equally profitable in Östergötland. This was because the ethanol plant was located in Östergötland, so the transport costs were the same for both systems in this province but were higher for the Energy system in Skåne and Uppland. Detailed analysis of the energy cereals grown showed that due mainly to the increased transport costs associated with the ethanol plant being located in Norrköping, the price of winter wheat for ethanol production in Skåne should be 0.06 SEK/kg higher than the price of feed wheat to achieve the same level of profit. In Östergötland the profitability was higher for bioethanol wheat both when delivered at harvest or after storage (in December). For delivery at harvest, for each percentage increase in starch content there was a bonus of SEK 0.02 per kg winter wheat produced, and also higher permitted grain water content on delivery to the ethanol plant. The price of bioethanol wheat could therefore be 0.08 SEK/kg lower at harvest delivery and 0.03 SEK/kg lower at delivery after storage without lowering the profitability compared with feed wheat. For Uppland the profitability for bioethanol wheat was comparable with that of feed wheat. Compared with wheat, the profitability of triticale increased more when it was used for bioethanol instead of feed. The price of oats for combustion rather than for feed could decrease for all typical farms without decreasing profitability due to the subsidy available for cultivation of energy crops and to the decreased transport costs when the combustion plant is located close to the typical farm. In this study timeliness costs had minor effects on overall costs, at most constituting 4% of the total. Lower quality requirements (falling number) on bioethanol wheat compared with food wheat resulted in lower timeliness costs for the Energy system, while timeliness costs for the other cereals studied were similar.