
1) Electricity source 2) Energy source 3) Generating facility 4) Generation need 5) Generator, of a sort 6) Start-up business 7) Widget toolkit
Found on
https://www.crosswordclues.com/clue/powerplant

PowerPlant is an object-oriented GUI toolkit, application framework and set of class libraries for Mac OS, created by Metrowerks. The framework was fairly popular at the height of the Classic Mac OS era, and was primarily used with CodeWarrior. It was designed to work with a GUI editor called Constructor; unusually for such programs, Constructor w...
Found on
http://en.wikipedia.org/wiki/PowerPlant

A powered aircraft’s source of power, usually either a jet engine or a conventional engine and propeller.
Found on
https://en.wiktionary.org/wiki/Appendix:Glossary_of_aviation,_aerospace,_an
No exact match found.