That sounds like a lovely idea, but remember that fusion, even a micro one, still needs a plasma containment system and a hefty amount of cooling. If you could manage that, the moss would thrive without the smoky scent of old furnaces, but I’d be more excited if we could harness the natural wind patterns and solar flux in a way that the forest itself helps regulate the energy. Still, it’d be great to see a prototype that keeps the ecosystem balanced.