Using Generators in Non-Emergency Situations

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An inherited tenant in one of my duplexes in PA had his electricity shut off by PECO for non-payment. Now he's using a generator for his electricity. He turns it on around 9 am and off at 10:30 pm. I can't imagine what a nuisance this is for the neighbors and other tenants in the house (let alone how stupidly expensive it is to run). It's been like this for a week already, but he anticipates having his power turned back on the beginning of this coming week.

For future reference, can I put a line item in the lease which prohibits a tenant from using a generator in non-emergency situations?