Engines hard to find as going for power generation?! Although a version of the RB211 (very modified without fan) is used in power generation the reason is more generally aviation logistics/economics related i.e. operators/owners start to part out engines instead of putting them through SV at great cost to sit on a trolley doing nothing...the critical parts are sold on or used as required...the existing engines are run out and the cycle continues...eventually leaving a smaller pool of cores all of which have to under go SV at considerable cost (approx $1.4 mil on an RB211 I saw quoted)...a lot of money for a small or cash strapped operator