while the geopolitical take is true, the economic sacrifice you'd have by not taking china's surplus is actually not benefitial.

The solar panels can enable other industries locally. For example, cheap and plentiful electricity can be used to produce local stuff that costs energy.

And solar panel production is not really "strategically" important - in a kinetic war, china can withold solar panels and it would not make a difference in the war.

Therefore, there's no reason not to import cheap panels.