It also means that the police already knew he grows. As its a legal grow even the county and state knows he grows. as he has filed the relevant paperwork.
Why would the police need to contact the electricity company when they can just look at their own records?
Well, you should ask him I guess. If you want a swag, my take is they (the state of CO) have been trying to find the coop growers. So they have been asking the power companies for lists of residential users with higher than normal power use. He probably popped up in a drag net of homes, and when they looked up his address, they saw he was a licensed med grower and decided to pay a visit.
Just because you use LED's doesn't mean you don't use power. A 1000w of LED light uses the same power as a 1000w of HID. They also put out the same amount of heat. Sure, you can get some savings since in some cases you can get away with fewer watts of LED, but it isn't a huge amount. And when you have 5k-10k watts in use, plus AC, you will stand out.
He just happened to be over the limit by enough they could pick him out in a fishing expedition. Again, I have ZERO first hand info. I'm just going by what he posted, probably in too much detail.
But it still shows that they can, and do, use your power bill to look for pc for a warrant.