Proud Co-Founder of Transition Town High Wycombe
Proud Member of the Low Carbon Chilterns Cooperative
Proud owner & retrofitter of Superhome 59
This website proud host of the High Wycombe Local Food Guide
Light up your life
Why devote an entire page of this web page to the humble light-bulb? As mentioned when we opened the Substitute Step, the electric light bulb has become a symbol of everything we hope we can do. It is simple, lasts longer and saves us money and carbon. It is a win, win, win situation. Yet, amazingly, way too few of us use them on the basis of their higher unit price to purchase. Prices may now be tumbling but for all the wrong reasons. We mass produce them in China and then ship them back to Europe vastly increasing their embedded Carbon.
Replace every light bulb in the UK with a CFL and we shut down one whole Power Station. Even so the cost of lighting is rising in terms of Carbon. 7.8 million tonnes a year in the UK and still going up. The reason? We like light. We are like a moth to the flame and we invent ever new ways to over-light our homes in very inefficient ways. Our friend the Compact Fluorescent Lamp (CFL) still only accounts for 7% of the market. Read on....
Moths to the flame...
The EU has now announced its intention to ban the incandescent light bulb by 2010 with the UK phasing out nearly all high-energy bulbs by 2011 for domestic use. Similar measures are afoot in countries around the world. Indeed the old joke about how many politicians it takes to change a light bulb has worn very thin in a few places. Still, it is all to the good. It is estimated that the EU phase out will save £5.4billion GBP in energy costs and 20 million tonnes of carbon. A similar ban in Australia should save 800,000 tonnes there annually.
Each UK home has, on average 23 light bulbs and our thirst knows no quenching. Electrical consumption for domestic lighting has doubled in the last 35 years and is expected to rise by another 12% by 2010. What is to blame? Well, halogen bulbs for one. Plus the modern craze for using lots of small inefficient halogens throughout a room so that we are flooded with light. We crave our light. It is seen as sophisticated and modern. Few people join up the dots between their use and electricity bills or their carbon output. Most of us have friends who leave lights on all around their houses all of the time as if there is no off switch. £180 million GBP is wasted every year in the UK due to lights being left on when not needed. That is 770,000 tonnes of CO2.
It is time for Post-Carbon Living to turn the tide. There is a new weapon at our disposal. It may not have quite pricked the public consciousness yet but the humble LED is our friend too. A few probably associate the LED with that little red light on appliances that indicate that it is on standby. Hence this is usually a negative association for the lower carbon enthusiast. However, the light-emitting diode can also be our friend. It is a piece of solid-state electronics that has been around for years but is slowly being refined for pure lighting duties. The reason? It is incredibly efficient as most of the power in comes out as light rather than heat. Sadly they tend to be very small but they can be clustered together for effect. Already the first LED bulbs are appearing in the shops as Halogen replacements for spot lighting. Some of you may have already seen the replacing the regular tungsten filament light bulb in handheld torches. This is an ideal use for them as it makes the batteries last much longer!
The LED has four times the life of the CFL. The life of a CFL is nothing to be sniffed at either (see "The CFL Revolution" - below). Already some retailers are starting to ONLY stock CFL's. Prices have plummeted making the economic case better and better each year. If one paradigm is surely to shift over the next ten years it will be this one. We will soon have forgotten Edison's invention altogether - like a bad nightmare.
The CFL Revolution
Your regular light bulb is known as an "incandescent" and is horribly inefficient. Just 5% of the energy is ever converted into light. The rest is released as heat. The CFL uses one-fifth of the power of the incandescent whilst lasting 12 times longer. Each one will save you £100GBP in their lifetime if used to replace one of those old-fashioned bulbs.
CFL's are now available for almost every mount, shape, size and application. (In fact the only type you cannot get are the pygmy bulbs although it is expected that LED's will cover all of that end of the market eventually.) CFL's came to the market in the 1980's. They are nothing more than a long fluorescent tube twisted or coiled into a smaller space. Actually it is a little more complicated than that. Some conventional fluorescent strips are really inefficient and yield a "G" rating in the UK. It isn't known why. Maybe someone can write in and tell us.
One CFL Supplier is now selling pre-packaged CFL Libraries. The way this works is that the Libraries are purchased centrally by the Community and then lent out to each person in turn. Everyone then tries each CFL for size around the different types of bulb mounts around their house. Hopefully, using them for a sort while may dispel most of the myths surrounding energy-efficient bulbs. When each borrower finds something they like they can then purchase these bulbs from a pre-prepared list. Click here to learn more.
What is more - there is a possibility that local Councils may have a budget for this sort of thing and can offer a Grant to purchase the Library. There are additional subsidy schemes from the Lighting Association that allows the most popular Bulbs to be purchased for only £0.40 GBP each (plus VAT). Our thanks to Chris Goodall for passing this information onto us. Post-Carbon Living will investigate further.
The Two Compared
The old fashioned filament incandescent light bulb was patented by Thomas Edison in 1880. It works by passing electricity through a filament made of tungsten. This heats up inside a vacuum tube that prevents oxidisation of the filament, ie, it won't burn out. The filament heats up and gives off light (although mostly just heat). The original Edison bulb had a lifetime of 1500 hours although, for some reason, the modern retail bulb only lasts 1000 hours. The lower life is probably caused by the way it is manufactured. The materials are cheaper and don't last as long as they could. In essence it has built-in obsolescence. It was made to be disposable. This suits the manufacturers just fine as it makes you buy a new one.
What of the CFL's detractors? Sure, the CFL used to be expensive, but not anymore. They used to be limited in what mounts they could be used with, but no more. Time was that you couldn't use them with dimmer switches. Now you can. They used to buzz, but not anymore. They used to be slow to start and slow to warm up. This was true ten years ago but most modern CFL's, and most brands, light up instantaneously to near full brilliance. (Although this is still not universal. Our research suggest some types & brands have a long way to go on this front.) The Society of Light & Lighting told the BBC recently that "they flicker less and warm up faster. Nor should people worry that they contain mercury, as it is a very small amount."
So, what criticisms remain? Often the claim that they are not as bright as old light bulbs is largely a matter of perception. Since they take a few seconds to reach maximum brightness then the human eye & brain can be fooled. We simply don't notice when it reaches full brightness. We just notice that it is not as instantly bright as an old fashioned bulb. However, there is more to it than this. The Lighting Industry Federation say that the claimed brightness equivalent on the maker's packaging is compared to equivalent soft white light bulbs. If you always had those at home then you are less likely to notice the difference. However if you used clear bulbs then they were a bit brighter hence this is not a valid comparison. Whilst the European Commission say that the equivalence can be calculated by multiplying the wattage by four the US Lighting Research Center suggests multiplying only by three. This second piece of advice contravenes our "Powerdown" principle. So, if in doubt, choose the lower wattage. We recommend task lighting for those fiddly jobs and for reading.
CFL output also varies with temperature and time. They may get up to 20% dimmer over time it is claimed but we can't find the evidence for this. Counter-intuitively it is also claimed that CFL's get dimmer the hotter they get. So, for example, recessed ceiling lights get hotter than those dangling in air, so may be 10 to 20% dimmer at operating temperature.
What about lifetime claims? Our experience is that, if you buy a lot of CFL's (particularly cheap Supermarket ones) then some of them will fail quicker than you expect. The advertised 10 year lifespan is only an average. So, on average, half will not last that long! Also the average is only calculated on the basis of switching the CFL on for three hours per day, then switching it off again. However, if your CFL gets lots more usage, and is switched on and off more regularly, then it will not last that ten year period. However, all things being equal, CFL's do last far longer than TFLB's.
What about energy efficiency? Normally a 5-to-1 ratio is claimed by manufacturers. However this is the optimum. It is "up to 80%" more efficient. An EC spokeswoman admitted that it could be as low as 60% in some circumstances. Either way it makes no difference. Even given the worse-case-scenario the Building Research Establishment reminds consumers that CFL's are still better than old TFLB's. What can get forgotten in the simplistic calculations are that old TFLB's got very hot so helped to heat your home in winter. This, of course, is completely wasted in summer time, plus, don't forget that Electrical Heating is currently more carbon-intensive than using Gas. The bottom-line is that engineers prefer to use a more conservative figure of 70% when crunching the numbers on CFL energy efficiency.
Don't be tempted to believe that burning candles is somehow more efficient than a light bulb. Apart from the obvious fire hazard a candle is 357 times less light-efficient than a CFL and 71 times less efficient than a regular incandescent bulb. Most of the energy is heat. Great if you are cold. Another surprising fact about oil is that generating electricity from oil to power a CFL actually produces up to 450 times more useful light than burning that oil in an oil lamp. Burning any type of oil or wax for light is terribly inefficient.
Natural Light as an alternative
Who would have thought of that? Obvious really when you think about it. Why reach for the light switch when the sun outside is far brighter than we could ever need? Windows to the south will give plenty of light but more glare whilst those to the west are best for that evening mood light. Natural light can relieve headaches, fatigue, stress and hypertension caused by artificial light.
As an aid to enhancing your use of natural light try painting your home interior with very light colours and use as many mirrors as you can get away with. Avoid obstructing your windows with net curtains, drapes or ornaments. Indeed, de-clutter all of your house and let the light flood in.
How about this as an alternative? The "Sun-Pipe" is a devices invented, marketed and installed by a company called Monodraught in the UK (there are alternatives - give it a 'Google'!). It is a one of a number of clever lighting and ventilation devices designed to use the power of the sun and wind to bring air and light to the interior of buildings. Arguably these used to be called 'windows' but the sunpipe is slightly more sophisticated in that it can channel light down a reflective tube so that it can be directed deep inside a building. For example it can go through an unoccupied roof space to the room underneath. Learn more at www.monodraught.com.