07-12-2020 | By Sam Brown
It was around 15 years ago when energy-saving lamps starting to enter the market as an environmentally friendly alternative to incandescent lamps. How do such lights work, why were they considered environmentally friendly, and how can such lamps cause damage to the environment?
The replacement of incandescent lamps?
If there is one technology that most miss, it’s the old incandescent lamps. These lamps provided instant light, were available in a wide range of powers, and their warm colours would help create cosy rooms. However, the use of incandescence to generate light is horrendously inefficient (less than 3%), and eventually, the carbon footprint of such lighting could no longer go unnoticed.
An alternative technology to incandescent lights, the Compact Fluorescent Lamp or CFL for short, suddenly rose in popularity due to its significantly larger energy efficiency (around 7-10%). While these lamps took forever to reach full brightness, looked ugly, and more expensive, their ability to save on electrical bills as well as having a longer lifespan meant that they took over very quickly.
What are CFL energy-saving lamps?
CFLs utilise the same technology that is found in standard fluorescent lights whereby a tube contains a very low-pressure atmosphere and a small amount of mercury vapour. Two conductors at either end of the tube, under normal conditions, are an open contact as the gas inside the tube is non-conductive. When a very high voltage is applied across the tube, arc discharge causes ionisation which in-turn creates a plasma. This plasma allows more current to flow, and thus the avalanching effect creates a conductive path for current to flow.
As the tube conducts electricity, the outermost electron in the vaporised mercury atoms are excited to a greater energy level. Eventually, these electrons fall back to their normal state, and when this happens, UV light is emitted. Since UV light is undesirable for standard lightning, the tube has a phosphorus coating which absorbs the UV light and emits visible light as a result of fluorescence.
CFLs, unlike standard tube lightning, also integrate all the driver circuitry needed to operate the tube including the ballast and terminals for use in standard lamp fittings (such as E27 Edison screw and Bayonet). The ballast is needed to limit the current as the lamp conducts electricity due to the negative coefficient between the tube’s resistance and ionisation. The ballast circuitry also provides the needed high voltage to initiate arcing inside the tube.
The Not-So Environmentally Friendly Nature of CFLs
One of the major advantages behind CFLs is their greater energy efficiency, and it is this reason that government action saw the ban on the sale of incandescent lamps. However, while these lamps can help to cut CO2 emissions, they also have an internal ticking time bomb that can cause massive ecological disaster if not carefully checked; mercury.
RoHS and REACH directives from the EU have gone out of their way to ensure that electronics do not contain harmful compounds such as cadmium, lead, and mercury due to their devastating effect on health. While a single CFL may not contain much mercury (a few mg at most), their highly toxic nature means that not much exposure is needed to become seriously ill. But the environmental benefits of CFLs saw such devices become exempt from these directives, and these lamps had instructions on them to be disposed of carefully in a recycling centre.
Move on a decade or so, information has recently come to light that as much as two-thirds of these tubes and CFLs are not recycled, but instead thrown in the trash. Despite the printed warnings on the packaging of these lights, consumers still throw them out in the regular trash as if they were incandescent lamps. Modern lighting technologies, such as LEDs, are quickly replacing CFLs. Still, a large number of CFLs in circulation means that there is a genuine risk of an ecological disaster waiting to happen, like an unstable volcano about to erupt.
What should be done to tackle CFLs?
Considering how the government instructed the installation of CFLs to improve energy efficiency, the government should also insist on all households to replace their lamps with LED alternatives and to properly dispose of their old lamps. Failing this, the environmental dangers of CFLs should be made clearer to the general public, and how such lamps can be disposed of properly.