A few months ago, I barely gave lightbulbs a thought. I never worried about start-up times, lumens per watt and colour spectra, or questioned whether I could find a suitable bulb for my most awkward sockets at home. The most exciting bulb-related thing to have happened to me was a late introduction, in my mid—20s, to recessed halogen spotlights.
Now, it’s bordering on an obsession. Everywhere I go, every room I enter, I find myself calculating the wattage of the lights. From my dentist’s chair last week, I noticed at least a dozen 50—watt halogens embedded in the ceiling and a smattering of fluorescent striplights (in addition to that super—bright lamp trained on my face). From my desk at work, I can count 160 striplights and 50 individual lightbulbs — some energy—efficient, many not, all switched on while it’s bright and sunny outside. In a tiny clothes shop in Bristol, in the west of England, I counted 50 boiling hot, 35—watt spotlights all pointed at walls or into clothes — and that was just in the first half of the shop. All that electricity being wasted as heat; all those extra carbon emissions . . . My mental maths makes me scowl a lot these days.
I’m not the only one with a bee in their bonnet about bulbs, of course. This year, newspapers and comment blogs have overflowed with (mostly angry) pieces about our gradual switch to greener lighting and, in particular, the parallel demise of traditional incandescent bulbs — now gradually being banned across Europe, much to the irritation of Euro— and climate change—sceptics everywhere. Lamenting the death of the incandescent bulb is as daft as complaining about cars becoming more fuel—efficient, or deciding you want a course of leeches instead of paracetamol to deal with a headache. Even if you don’t buy into the climate and energy—saving argument, it makes sense to ditch incandescent bulbs purely on the grounds of the money you’ll save on electricity bills.
My own transformation began with an innocent question about my life, as I was finally getting round to auditing the carbon footprint of my home earlier this year. As part of a larger plan to green my house, I had asked Russell Smith of the sustainable building company Eco Parity to carry out an energy survey of my freezing, energy—hungry Victorian terrace home. He identified lighting as a major issue — the cost of powering the copious lightbulbs hanging from my ceilings and screwed or bayoneted into table lamps was spiking up my energy use and, consequently, my carbon footprint.
Those incandescent bulbs were identical to the vast majority of lights in the vast majority of British homes. In fact, most of the world still gets its artificial lighting from these glowing filaments of tungsten housed in a glass—enclosed vacuum, a design that has been around, virtually unaltered, for more than a century. In our climate—aware times, they represent an indefensible energy burden: up to 95% of the electricity each bulb draws is wasted as heat.
In total, lighting accounted for 28% of my home’s energy use and more than half the electricity bill. I was producing around 1.5 tonnes of CO2 every year just with my lights. This had to change. I had always known that swapping incandescent bulbs for more energy—efficient compact fluorescent lights (CFLs) would be one of the easiest ways to cut my carbon footprint, but I’d never actually quantified what this meant for me. CFLs, a miniature and more sophisticated version of fluorescent striplights, last around 10 times longer than incandescent bulbs and use up to 80% less energy.
Over the next few months, I spent (probably too many) evenings, weekends and lunchtimes hunting out and testing different energy—saving bulbs, each representative of even more cutting—edge lighting technology than the last. I got frighteningly familiar with terms such as GU10, R50, E14 and E27 (the technical labels for different shapes of bulb and socket — look, I did this so you don’t have to). And I saw the future too, in super—bright light—emitting diodes (LEDs). Familiar in car dashboards and bicycle lights, they smash all records for energy efficiency. In a few years they will be all over your home too, and with none of the perceived stigma of CFLs.
By the time I emerged from this trek through the light side, my whopping 1.5—tonne CO2 habit had dropped to less than 150kg per year. Think what would happen if everyone made such a cut. According to the UK’s Energy Saving Trust (EST), lights account for around 20% of the electricity bill in an average home. Britons spend around GBP2.3bn each year on electricity to run their home lights, and if everyone switched their old—style lights to energy—saving alternatives, the electricity saved in a single year would run the country’s street lighting for four and a half years, or provide electricity for every house in London for nine months. If every UK householder replaced just one 100—watt incandescent bulb with an energy—saver, the carbon saved would be equal to taking 200,000 cars off the road for a year.
Governments, too, have realised this is a quick win. At the beginning of this month, incandescent lightbulbs rated above 80 watts were banned across the 27 countries of the EU. Next year, bulbs over 65 watts will be banned, and so on in the following years until incandescents disappear entirely by the middle of the next decade. Bans have also been announced in countries around the world from the US and Australia to Brazil, Turkey and Malaysia.
Not everyone is happy, though. According to their detractors, CFLs give out cold light, take ages to warm up, and might even make you ill. “Nearly all of our work seems to be trying to batter these myths down,” says James Russill, a lighting expert at the EST. “There are a lot of wrong perceptions about energy—saving lightbulbs. In the early days, as the technology was developing, there were issues with warm—up times, general light output and their size. These are still at the forefront of a lot of people’s minds — but the modern technology counters all of these problems.” It’s not as if the incandescent bulb hasn’t had a good run. Invented in the late 19th century either by Joseph Swan or Thomas Edison (depending on which side of the Atlantic you live), the first designs generated light by passing electricity through a carbonised filament of bamboo; when this got hot, it would glow orange. The longer the filament, the more light came out, so to ensure bulbs remained a practical size, later versions used long strips of bamboo curled into tight coils.
By the start of the 20th century, tungsten had replaced bamboo because it was the material that survived longest at the hottest temperatures. The coiled filament was curled upon itself to create an even brighter filament — the so—called “coiled coil” — and placed in a vacuum or inert gas to give the filament longer life. And that, largely, is how incandescent lightbulbs have stayed for more than a century.
Fluorescent lights, meanwhile, first appeared more than 80 years ago. By passing electricity through mercury gas, they produce lots of ultraviolet light that is absorbed by a phosphor chemical lining the inside of the glass tube — the phosphor then re—emits the energy as visible white light. A fluorescent tube is more expensive to make than an incandescent lamp, but the process it uses to make light is at least five times more efficient. (The efficiency of a lamp is measured in the amount of light, measured in lumens, produced per watt of power it uses: an incandescent light produces around 10 lumens per watt, halogen spotlights push that to around 20, while modern fluorescents produce 50—60.) Fluorescents swamped offices and factories in the 50s and 60s, yet inefficient incandescent lights remained popular in homes, largely thanks to their warm yellowish light. And things would have stayed that way if it wasn’t for a development in the phosphor chemicals in fluorescent lights in the 70s.
“Instead of producing one phosphor that produced white light, we took three — green, red and blue — and mixed them to get white,” explains Mike Simpson, technical and design director of Philips Lighting. “One of the spin—offs was that these were less sensitive to heat so you could run them hotter, but they also gave much better colour quality.” It also meant manufacturers could modify the colour of the light coming out of fluorescent tubes, and make them thinner. By 1980, the first compact fluorescent lights were being made by bending thin tubes double and putting them into a glass container, much like a jam jar, attached to a bayonet socket base. “Back then, you’d take out a 100—watt incandescent and put in a 20—watt fluorescent,” Simpson says. “Everything that has happened in the past 20 years has been to make it smaller and more efficient.” At home, I had a mixture of incandescent bulbs rated from 20 to 100 watts. The kitchen alone had seven reflector bulbs at 50 watts each, the upstairs bathroom had another four at 40 watts — in total, I had at least 1,500 watts of lighting around the house.
Replacing the main light in each room was simple: these days, there’s a whole range of cheap, reliable CFLs. The colour of the lights wasn’t even an issue (if it matters, you can often choose how yellow you’d like the light to be) and the start—up time for my new lightbulbs was near—instantaneous.
More problematic were the downlighters in my kitchen and bathroom. There seemed to be fewer low—energy options, and it took a lot of digging to find suitable spotlight—shaped bulbs. I eventually found some made by the low—energy lighting company Megaman on specialist lighting websites (although I have since seen the same bulbs at DIY stores, and they are becoming more available at mainstream stores and supermarkets).
The difference the new lights has made to my carbon footprint and my wallet is clear: from 1,500 watts of lights in the house, I now have around 150 watts doing the same job. By removing 90% of the lighting power, I have reduced my monthly electricity bills by around 60%.
So is that the end of my lighting story? Not quite. Where CFL technology was 20 years ago, another lighting technology is ramping up to further reduce our energy bills. LEDs have been around since the 60s, producing light by passing electricity between thin layers of different semi—conductor materials. Until now, they have only been useful as indicator lights on telephones, car dashboards and dot—matrix displays. They are costly, used only to be available in certain colours (reds or oranges, typically), and weren’t bright enough for lighting entire rooms.
In the mid—90s, however, Japanese scientists invented the first blue LEDs. By coating these with a phosphor, LEDs could finally produce white light, prompting the big electronics companies to accelerate their development of LED bulbs. Philips recently produced a 3—watt bulb that has the same light output as a 35—watt halogen incandescent bulb — it is expensive (GBP25), but Philips claims it will last for 15 years. Factor in the amount of electricity the bulb will save and, overall, it could turn out well for your pocket and the planet. If all of the UK’s domestic lighting was switched to LEDs, the electricity burden for lighting could be 10% of what it is today.
Like all technology, LEDs will no doubt get better and cheaper. Is it too much to hope that, within a couple of decades, all the lighting in one house will use the equivalent energy of a single incandescent lamp today, bringing the carbon footprint of lighting our homes to virtually nothing? At least that would stop me scowling at shopkeepers.
