The grass grows and the sand settles, but new challenges arise. The grass grows haphazardly, blocking the photovoltaic panels, reducing their conversion rate, and literally, stacking up fire hazards in winter. The staff have tried manual weeding, spraying herbicides, and even thinking about raising the photovoltaic panels, but they could not fully solve the dilemma. And then nature, as is so often the case, came up with its own solution.

"Rather than paying someone to mow the grass, it's better to let herdsmen put their sheep here," says Zhu as he recalled his flash of "inspiration" at that time. The park invited the surrounding villagers to raise "photovoltaic sheep". They built four sheep pens for free, so that the "photovoltaic shepherd" could start their "old business" at zero cost.