The (potential) new planet is a long way away. Most planets are named after Roman Gods but there seems no reason why there shouldn't be a Greek name, so here are my three suggestions:
Janus - Roman God of Beginnings, Endings, Transition, Doorways and Keys.
Hades - Greek King of the underworld and the dead. That seems appropriate for a planet way out in the darkness of space. Unfortunately Pluto is the Roman name for the same God so there might be some confusion.
Hermes - Greek God of boundaries, travel, communication, trade, language, and writing.
The new name needs to be easy to pronounce and spell and appropriate for different languages, some Greek Gods have names difficult to pronounce or spell.
Looking at the orbit here:
http://www.sciencemag.org/news/2016/01/feature-astronomers-say-neptune-sized-planet-lurks-unseen-solar-system The orbits of the small objects spinning around the new planet (Sedna and others) would seem to come within Earth's orbit in the future creating a potential risk to us.
No chance that PV panels will work there, but if it's got a lot of methane or hydrogen, those could be a power source.
