Fig.2. The supply (green line) and demand (red line) curve for cereal straw. When there is a shift in demand to the right (arrow illustrated) due to an increase in local interest, the price of cereal straw increases and this encourages baling (illustration purpose).
Article: Glithero, N.J., Ramsden, S.J., Wilson, P. (2013) barriers and incentives to the production of bioethanol from cereal straw: a farm business perspective, energy policy, 59, 161-71.
The main renewable transport fuels for the UK are biodiesel and bioethanol generated through the second generation fuel technology, which does not based on crops that have alternative use for human consumption. The Biotechnology and Biological Sciences Research Council (BBSRC) Sustainable Bioenergy Centre makes use of cereal straw to synthesise bioethanol. This method does not compete directly with food production supporting the second generation fuel technology. However, using straw-based raw material may cause a potential depletion of soil organic matter if straw is not incorporated into soil which is around 1.45Mt of barley and wheat are chopped and incorporated into soil.
Barriers of using second generation fuel technology include the farmers reluctancy to grow energy crops since the straw has many alternative uses such as incorporation into soil to enhance soil organic matter. Costs and difficulty of storage and transportation and farmers operate in a much freer market environment with attendant risks and opportunities. Barriers to baling straw mainly relate to the timeliness of operations in establishing the next crop and perceived benefits of straw incorporated. Other reasons include difficulty in achieving dry straw to bale and lack of local interest in straw. A ‘good price’ for straw would therefore encourage baling.
Fig.1. Bales of cereal straw (photo: goo.gl/y9wnQv)
A survey was undertaken to gain information relating to contract implications of bioethanol feedstock production, dedicated bioenergy crops, straw use, straw volumes baled, crop cultivations, cereal variety choice and straw incorporation. Contractual implications of bioethanol production straw-feedstock supply, short-term contracts were typically favoured and the majority were willing to supply straw for the same length of time as the contract. The majority (71%) of farmers cited the same response for both the consecutive number of years of supply and maximum contract length, which was 2 years. Supplying a fixed area of straw for a fixed farm-gate price were recorded as the most popular response. East England farmers were almost twice as likely as North England farmers to choose this option (40% and 21% respectively). The most frequent farm-gate price cited was £50 t-1.
According to the data derived from the national assessment of potential straw supply, the low-value nature of feedstock will lead to regional restrictions on the demand of feedstock as bioethanol plants seek to achieve sufficient feedstock supply while reducing the transport distances involved. Policy messages must address the potential dichotomy of encouraging bioenergy production without overly compromising food production as mentioned in the UK Code of Good Agricultural Practice, which recommends straw incorporation to achieve both fuel and food security.
As a conclusion, ensuring feedstock security which consists of energy crops and agricultural crop residues (cereal straw) is a necessary condition in order for second generation technology to play part in meeting the EU target for renewable fuel use. Despite the barriers to the use of straw for bioenergy exist, two-thirds and one-third of farmers would willing to supply wheat and barley straw respectively for bioenergy purposes. Policy interventions in the market for straw as a bioenergy feedstock integrated with the sustainability of food supply may be required in order to incentivise farmers to engage in this potentially new market, to achieve the combined goals of food and fuel security.
Enhancing efficiency of cereal straw for biofuel production; 3:32min; Hong Kong university
Converting straw inti biofuel; 4:50min; Sunliquid company