A luminaire which provides illumination (in some cases, in a coordinated manner with other nodes of a lighting network) in an industrial environment is further configured to serve as a node of a wireless process control or industrial network, which may be a mesh and/or time-synchronized wireless network. Upon detecting a loss of mains power and/or other triggering condition, the luminaire node allocates an amount of available battery power to maintain the routing of process control messages, and allocates at least some of a remaining amount of available battery power (if any) for performing lighting activities such as driving illumination and/or lighting-related communications. The allocations for (e.g., the relative priorities of) support for process control and support for lighting activities may be based on an allocation configuration and/or based on instructions received from other components of the process control network and/or the lighting network, which may include user interface devices.