What Watt is What?
How much do you know about the role your choice of lighting plays in reducing carbon emissions?
Most of us have mastered the basics such as screw or bayonet, but what about the eco credentials of various new types of bulbs?
When traditional incandescent bulbs were phased out, a brighter future beckoned. However, with a dazzling array of bulbs for sale, how can we distinguish which are most beneficial for the environment AND our pockets?
In the Beginning … Let There be Light!
Ever since the introduction of the National Grid in the 1930s, electric lighting has been ubiquitous across British homes. Although there was a shift towards the use of fluorescent lighting tubes in the 1960s, incandescent tungsten filament light bulbs remained our main source of domestic lighting until very recently. Standards solutions for lighting our homes became established with the typical 40, 60 or 100 watt incandescent lamps available. Energy was cheap, and most of us had little concern that our light bulbs were only 10% efficient, generating just a miserly dozen lumens of light per watt.
Eureka! Or Not?
Only since the new millennium has electric lighting had its “light bulb moment.” In 2012, a phased ban on the sale of incandescent light bulbs was completed in the UK, following EU directive to reduce energy use of lighting. The UK government said the ban would bring an “average annual net benefit” of £108m to the country between 2010 and 2020 in energy savings.
While the positive environmental benefits are undeniable, the ban did not initially achieve as much of a reduction in energy use as was first hoped. Early Compact Fluorescent Lamps (CFLs) – seen by many as the heir apparent to incandescent lighting – were not well received by all consumers. Despite the fact that CFLs use between 1/5 and 1/3 the energy of incandescents, and typically save one to five times their purchase price over the course of their lifetime, many people weren’t thrilled at the idea of switching over. Some found the pallid light output of CFL bulbs less aesthetically pleasing than the warmer hues of most incandescents. Furthermore, the trend to use more lighting in our homes and the popularity of halogen downlighters somewhat halted the decline in energy use.
Here’s an overview of equivalence between the three main lamp types available today, compared with the now obsolete tungsten incandescent lamps:
Halogens are incandescent lamps using a filament suspended in a small amount of halogen (iodine or bromine) gas. They work at high temperature and can be more efficient than traditional tungsten incandescent bulbs. Halogen lamps produce an attractive bright white light, reach full lighting level immediately and can last from 1,000-3,000+ hours. Currently, they do not meet the 45 lumens/circuit watt requirement for low energy lighting. From 2018, even the most efficient halogen lamps will be phased out of production.
Though halogen lamps have been used very commonly for downlighting, their high-energy consumption and relatively short service life are now recognised disadvantages. Even the best halogen lamps have efficacy ratings and service lives which are well short of the performance offered by CFLs and LEDs.
Compact Fluorescent Lamps (CFLs)
When incandescent bulbs were being phased out, CFLs were the most obvious replacement, offering potential savings of up to £50 over the lifetime of the lamp.
CFLs are highly energy efficient (usually class A) and remain a good choice for areas requiring long periods of lighting, for example living rooms. Earlier CFLs had inconveniently long warm up times before reaching a good level of light output, however this aspect of performance is less of a concern with newer CFL technology.
Both CFLs (and dedicated fittings for CFLs) are available in a wide range of sizes, shapes and colours. Some CFLs are suitable for dimming but require specialist, compatible control gear.
Some CFLs have glass that is bent or spiralled to achieve a more compact shape. There are also ‘bulb’ designs although these include a second layer of glass and are therefore less efficient, typically energy class B.
LEDs (Light Emitting Diodes)
In an LED lamp, an electrical current is passed across semiconductor material (usually silicon). As electrons migrate between charged atoms in the semiconductor, photons of light are released.
LED lighting is the most efficient type of lighting system currently available for domestic use. Technological advances, continuing cost reduction, rapid product innovation and diversity make it almost inevitable that LEDs will be the predominant form of lighting in the near future.
LED lamps are now available for almost every domestic lighting purpose. Lamps are available that can be fitted into traditional pendant light fittings containing bayonet, cap or Edison screw lamp holders.
But aren’t they really expensive? Granted, they’re often several times the price of other bulbs, but LED lamps are highly energy efficient and have very long lifetime expectancy, meaning they are far more cost-effective in the long run.
LEDs – the Wise Choice for a Brighter Future
LED light bulbs have a longer life span
When looking at the average life span of LED, conventional incandescent and CFL light bulbs, it is crystal clear to anyone why LED lighting is by far the best solution. An average CFL’s lifespan is approximately 8,000 hours, whereas incandescent light bulbs only light for about 1,000 hours. LED technology, on the other hand, has an average lifespan of an impressive up 45,000 hours or more. This means that if you used the light for six hours a day it would last over 20 years – quite possibly longer than you might live at the property!
LED bulbs help you save money on your electricity bills
LED lights use less watts per unit of lumen generated. Therefore, they are not only much longer-lasting in lifespan but also lower your electricity bill providing 100 or even up to 200 lumen per watt. CFLs, in contrast use about twice the amount of watts and incandescent light bulbs around 10x as much power with only ca. 18-20 lumen per watts. In a home or residential setting, this difference in lifespan and efficiency between incandescent lighting and LED lighting helps you to significantly reduce your electricity bill.
LED lights are non-toxic and greener than other alternatives
Apart from the compelling differences in efficiency, lifespan and therefore also electricity cost, LED lighting is also the greenest solution available on today’s markets. For one, LEDs, in contrast to CFLs, do not contain the highly toxic mercury, which is harmful not only to the environment but also to your personal health.
LED lights are free of toxic materials and are 100% recyclable, and can help you to reduce your carbon footprint by up to a third!
Most important for issues regarding global warming and environmental change, LED light bulbs release substantially less CO2, sulphur oxide and nuclear waste. Taking into consideration the increasing threats of global warming and the effects of CO2 emissions on our planet and personal health, it goes without saying that LED bulbs are by far the greenest lighting solution so far.
How Else Can Lighting Choices Help Save Money and the Planet?
- Use multiple switches
When installing lighting in a large open-plan space, install multiple switches to cover the different areas. That way you can restrict your use of lighting to the area you want to use.
- Install motion detectors
When installing security lighting outdoors, make sure the lights have built-in motion sensors or timers so they only operate when needed.
- Keep lights clean
A dusty light bulb or a dirty lampshade can obstruct as much as half the light. Dust the bulb and wipe or wash the shade regularly.
- Be natural
Install skylights in darker rooms or as natural downlights in work rooms such as kitchens. If you’re buying or building a new house or apartment, or are undertaking a renovation, position the rooms and spaces where you spend most time during the day to the north or northeast so they capture the lion’s share of daylight.
- Turn off the lights
Unplug appliances as soon as you stop using them. This advice is as old as electric lighting itself, and is still the key to saving on use and costs.