Something like that wouldn't be flagged as suspicious. If you were using a large amount of power for 16 hours a day for a few months and then for 12 hours a day for a few months, that would be suspicious because that usage profile matches a marijuana grow.

They can also "fingerprint" certain power usage like a refrigerator and filter out that noise from the power usage profile to eliminate other innocuous things to build a stronger argument that an illegal grow is happening. The profile of an electric car charging plus tracking data on your phone would eliminate the power usage from charging as being suspect, but that would require a competent detective actually doing their job properly...