Bulb costs have come down from what they were a few years ago. In this blog, I will discuss each of these topics in more detail. If you are thinking about replacing some of your incandescent bulbs and saving some money on energy costs, you’ve come to the right place. They are essentially a miniaturised version of the strip lighting by which shoppers and workers everywhere have been lit for decades. Indeed, mercury sealed within the glass tubing of a Compact fluorescent bulbs amounts to about 5 milligrams, a small full-stop, or period, worth. No mercury is released when the bulbs are intact or being used. The mercury is present in the bulb as a vapour that glows when an electrical discharge is passed through it, giving the bright white light.