> "According to the current technical parameters, the annual production of starch in a one-cubic-meter bioreactor theoretically equates with the starch annual yield from growing 1/3 hectare of maize without considering the energy input," said Cai Tao, lead author of the study.
It sounds like they're trying to save on land and freshwater, not energy or raw materials.
https://phys.org/news/2021-09-chinese-scientists-starch-synt...