I'm not the doomer here. I'm critiquing the doomer's view, i.e. deep ecology.
The question is whether we can harness solar power without the backdrop of civilization. It's civilization that the deep ecologist thinks we need to scale back to respect the inherent value of all living things. Can we collect and store immense solar power without the industries and magnitudes of civilization? And what would we do with that power if we had it? Would we use it in an ecologically friendly way?
I'm just considering the deep ecologist's objection to civilization. Adding solar power to the mix doesn't necessarily address that objection.