I'm debating purchasing a Sense energy monitor to monitoring my commercial unit's power usage my electricity cost varies from $200 - $500 a month. I have 7 units. these monitors aren't cheap they cost $300 each. I'm not sure if the juice is worth the squeeze. the sense energy monitor has great software to hone in and identify what's using the most energy. I'm also trying to find out if my town does a free energy monitor which can be a cheap alternative.