Effect of a snow mass passing through an open-type cross-flow turbine on the power generation

Small-scale hydropower generation is increasingly recognized as a distributed power source with low environmental impact and high disaster resilience. In Japan, snow accumulation in snowy regions can be carried by water flows, impacting the performance of microhydroturbines. This study performed field experiments using spherical snowballs to replicate these snow masses. This study aims to evaluate the response of an open-type cross-flow hydraulic turbine to snowball interference under winter field conditions. Snowball was released upstream of the turbine, and detailed observations were made of both the turbine’s output variations and the snowball behavior. The experiments revealed that when the snowball diameter was approximately equal to the rotor blade spacing, the power output temporarily decreased but quickly recovered. Conversely, when the snowball diameter exceeded the blade spacing, the power output experienced sharp decline, with recovery times varying across experiments. It was also confirmed that the compression, crushing, and downstream discharge of the snowball by the blades influenced the output fluctuations. These findings provide initial insight into the behavior of open-type microhydraulic turbines under snow mass interference, which is relevant to winter operation in snowy regions. • Snow masses passing through hydraulic turbines affect power output in irrigation canals. • Field experiments simulate snow mass behavior to evaluate turbine performance. • Turbine design insights are provided to enhance efficiency in snowy conditions. • Larger snow masses lead to turbine output reduction and recovery times vary. • Snow-resistant turbines improve power generation in regions with heavy snowfall.