Did you purchase a new appliance recently?  Appliances, large and small, use energy and when you add new items to your home, your overall bill is likely to go up.  When you replace an old appliance with a new one, you can usually expect your energy use to go down due to a higher efficiency.  If, however, the new appliance has a much larger capacity or has more convenience features, you may find that your energy use stays the same or goes up a little.  This doesn't mean your new appliance isn't more efficient, it just means you are doing more with it.