@Mike Landry I was curious for a comparison so I just checked...my family of 3 used 1,114 kwh last month in an all electric house and we run the dishwasher at least once per day and the washer/dryer at least twice each (don't ask).
Anyway, if it's not too big of an inconvenience, ask your tenant to start isolating things. Continue as normal with nothing changed for 2-3 days. Check the electric meter at the same time every day and record the reading. What's the average daily? Assume it to be around 100 kwh based on the report of 3,000 per month. Then target some systems one day at a time and see what happens. Ask your tenant to kill the hot water at the panel when they leave for work and turn it back on in the evening. Did that change the reading? Look for a mild day in the forecast (if there is one coming) and kill the hvac at the panel (not at the thermostat) and see if that affects anything. Next, ask if they can go a day without dishwasher, washer and dryer. Ask if they can shut down their computer/office set up for the day, possibly on the weekend.
My gut tells me that it's the hvac, or as someone else mentioned, the grow lights. Other major systems/appliances should just break down but should not consume more energy before they do so.