Once you live on a small island without any fossil fuels, you’ll have to pay a premium price as the oil for power plants is imported. Also, it can vary a lot depending on what you are using (oven, heaters, type of lights/ TV, fridge, etc.). I felt a considerable decrease when I switched to smart bulbs such as
https://www.vont.com/product/vont-bulb-color-smart-light-bulbs-smart-bulbs/. The amount of energy they consume is much lower, and if you are not living in a one-bedroom apartment and you have a lot of light, then the energy savings are considerable.