Datacentre administrators don't know how to run utilities.
Imagine replacing the word "power" with "sewage" and try to see if you would entrust the functionality of your toilet to your local friendly sysadmin.
No. You'd never ask a system administrator to administer your plumbing. Neither should you ask your system administrator to maintain a diesel power generator. Diesel generators have more in common with automobile internal combustion engines and in the high power segment, airplane jet turbines. In fact, many turbine cores are used as both airplane jet engine and as terrestrial power generation unit.
You're basically asking the wrong people to maintain the infrastructure.
When I worked in a DC the HVAC guys did the cooling. The electricians did the power and genset. We also had a local GE guy who did the engine part of the genset. These aren't sysadmin running generators. They are specialists hired for the job.