Hello.
Why was relation 15987302 created at all?
As documented in https://wiki.openstreetmap.org/wiki/Relations_are_not_categories relations are not intended as "collections" of somewhat related features into one group.

Additionally, as documented in https://wiki.openstreetmap.org/wiki/Proposal:Power_routing_proposal/Tagging_similar_to_Transportation_routes type=route + route=power relation type is only in the proposal stage and was never accepted as a community standard.