One of the best ways to save money each month is to do everything that you can in order to reduce your energy costs. To save money on energy costs, you can start by changing a few behaviors. When it comes to lights, they should only be on at night, and when you are using the room. The heater and air conditioners should be turned down, as should the refrigerator and freezer. Consider installing high efficiency light bulbs and windows. An instant water heater uses less energy than a water tank. A heat pump is more efficient than a furnace.