Impact of blade angle on miscanthus harvesting energy requirement

Miscanthus is emerging as a promising feedstock for domestic biofuel production. However, inefficiencies of the machinery that is used for harvesting bioenergy crops such as miscanthus currently prohibit commercial production. The performance of a mower-conditioner used to harvest miscanthus was evaluated, and modifications to the disk head were made to allow the machine to operate more efficiently. It was also hypothesized that the harvest energy requirement of the mower-conditioner in miscanthus could be reduced by increasing the blade oblique angle. Blades with oblique angles of 20° and 30° were manufactured and fitted to the disk mower-conditioner. When combined with data collected from a real-time yield sensing system, the data collected regarding the machine performance resulted in point-specific and overall machine energy consumption information. The 30° oblique angle resulted in a 27% reduction in the energy requirement, with an energy consumption of 13.5 MJ Mg^-1 as compared to 18.5 MJ Mg^-1 for the conventional straight (0°) blades. Further studies are needed to examine the overall life of the angled blades as well as the feasibility of their application to other crops harvested by disk mower-conditioners, such as hay and forage.