Environmentally friendly options for replacing incandescent lighting are usually either Compact Fluorescent Lamps (CFL) or Light Emitting Diode (LED) bulbs.
Compact Fluorescent Lamps
CFLs operate similarly to conventional fluorescent lamps where electricity is used to activate mercury vapor that resides in the glass tube. The current affects the mercury atoms to make ultraviolet (UV) light which is not visible to the eye. The photons from the ultraviolet light hit a phosphor layer inside the bulb housing to emit photons of visible light thereby creating light output from the tube. The ultraviolet light may cause fading in paintings or textiles. The mercury contained within the lamp means that the light bulbs need to be properly disposed of as compact fluorescent bulbs dumped in landfills burst, causing mercury to be released, draining into the ground, ultimately contaminating the food chain. Some states, such as California, ban the disposal of mercury-containing bulbs in the trash. Some state laws require fluorescent bulbs to be collected as hazardous waste or properly recycled. Check with the EPA site to help you with proper disposal procedures according to your state, or you can find a recycling center near you at Earth911 Cabinet Closet Lights B08CF4H5XZ.
Unlike fluorescent tubes that don’t contain circuitry, compact fluorescent usually integrate all of the necessary circuits in the bottom of the light allowing the single unit to be used in a standard incandescent light bulb socket. CFLs come in a variety of styles and shapes, but one will often see them in a tube or spiral option. Higher surface area allows for a higher light output in CFLs.
Solid-state lighting, more commonly known as LED (light-emitting diode) lighting is a solid semiconductor light source that doesn’t use a gas tube like that of the CFL. Light from an LED is made when electricity is applied through the semi-conductor doped with impurities to create one half which is a “p-side”, and another half that forms the “n-side”. The charge-carriers (electrons and holes) flow into the p-n junction where these two halves meet, and releases energy in the form of a photon, thereby creating light. The color of the light output depends on the materials forming the p-n junction. There is no filament to burn out, and unlike CFLs, LED lights do not contain the toxic mercury, nor do they emit ultraviolet light.