Power in Motus Gridia begins locally, but it does not end at the Grid boundary. Each community produces what its site can support and stores enough for ordinary use, while the Hub holds a reserve for the whole cluster.
On strong days, surplus flows outward. When local output falls, the shared reserve sends power back before a shortage becomes a failure.
Local supply will always vary with the weather. Demand can rise without warning, and equipment sometimes has to come offline for maintenance.
The site itself also determines which forms of generation make sense. The Hub gives all of that variation somewhere to go, turning separate power systems into one dependable network.
The principle is the same one used by the Magway. Each Grid keeps meaningful local capacity, while the cluster provides continuity beyond the boundary.