on Nov 22nd, 2006
Light of my life
According to the International Energy Agency (IEA), “19% of global electricity generation is taken for lighting— that’s more than is produced by hydro or nuclear stations, and about the same that’s produced from natural gas.”
Most people will now be familiar with CF or compact fluorescent light bulbs and the environmental benfits they bestow - they last much longer (roughly 10x) than conventional tungsten bulbs, they run cooler (so more power is used to make light rather than heat) and consume less than a quarter of the electricity for the same illumination levels.
It all makes perfect sense until you look at some of the drawbacks;
- The colour ‘temperature’ of the light seems colder than conventional lighting, OK for kitchens and bathrooms but not ‘moody’ enough for some other areas of the house.
- They are bulky - in itself this is not a problem, but I do wish lampshade manufacturers would wise-up to the fact the CF bulbs need more space otherwise they end up protruding from the lamp and looking rather naff.
- They use small amounts of mercury and so care must be taken when disposing.
- They can’t be dimmed to set the lighting levels at their most appropriate for the situation (although dimmable models are coming soon aparently).
If you can forgive their deficiencies (and let’s face it, some are just because we are so used to other ways), they make perfect sense and are an easy way to help green-up your home or workplace. Whilst some may shrug off the colour temperature differences, it does have a significant psychological effect on people - studies have shown that shops with good ‘natural’ lighting (or natural-coloured lighting) can increase sales by up to 40%, so it clearly makes a difference!
If you don’t fancy the idea of CF bulbs, then another development is just starting to come to market and may be the ideal solution for everyone. LED (Light Emitting Diodes) have been around for 20 or so years, primarily used for warning lights on cars and appliances. They consume miniscule amounts of power and last typically up to 100,000 hours. But until now they’ve never really been bright enough for anything other than mini-torches and the like.
The latest generation of ‘Power LEDs’ are set to change the lighting market considerably, and in a stroke, make it greener too. ‘Power LEDs’ don’t produce heat because they don’t emit either infra-red light or ultra-violet light (which also means they won’t fade the items they are illuminating) and hence you see the colours of objects exactly as they are in daylight. They can also be dimmed without altering the colour.
So how bright are they? Well, a 40w incandescent bulb emits 175 lux (a measurement of brightness) at 50cm, a 10w halogen bulb emits 50 lux, whilst a 1w (yes one watt) ‘power LED’ emits 375 lux at the same distance - that’s pretty incredible!
Don’t confuse ‘Power LEDs’ with a lot of the cheap and naff imported rubbish found in some DIY and lighting stores at the moment - the cheaper stuff (like most LED torches) uses an array of ’signalling LEDs’ which are anything from 10 to 45 times less bright than the new ‘power LEDs’.
Power LEDs are starting to become available now and should make a huge difference to the way we look at task and background or effect lighting and the accompanting energy usage. They will also appeal to people wishing to live ‘off the grid’.
There’s one final issue about lighting that I have been thinking about - when you leave a room, it makes sense to turn out the light. But what if you think you may be popping back in a few minutes - is it more efficient to leave the light on or turn it off and then on again when you return? Well here’s one answer I found;
Standard incandescent: turn off even if you leave the room for just seconds. Compact fluorescent: turn off if you leave the room for 3 minutes. Standard fluorescent: turn off if you leave the room for 15 minutes.
Further Information:
Treehugger: How to green your lighting
Glen Hunter
Illumineer
This power led light sounds very efficient. The heat from halogens is enormous, we used unfashionable strip lights in our new kitchen, due to the economy and much better spread of light. But the power led light would look as neat as the halogens without the heat and with more spread of light. I hope they are not excessively expensive, as I would like to try them.
[…] Of course, there is another alternative. That is to reduce the amount of power you consume. We have so many electricity consuming gadgets (are they really all necessary?) and devices which are left on standby (for standby read – still consuming electricity) that simply making an effort here will reduce our personal electricity consumption. We can make further efforts by purchasing energy saving lightbulbs (and switching off lights when not needed), purchasing energy efficient appliances and much more (most of which is fairly obvious). […]