19 Feb 2008
Another thought about lighting. CFL's (compact fluorescent lamps) still use around 10 W of electricity, take a while to 'warm up' to full brightness and have a life expectancy of around 1500 hours. Thus the life expectancy and energy usage are improvements over traditional incandescent bulbs.
However, I think LED lighting might have a big part to play in the future too. LED performance seems to be on the up in terms of brightness and colour ranges (i.e. from cold hard white for shops through to warmer tones for domestic use), whilst maintaining the stunningly low energy consumption - less than three or four Watts for a 35 W equivalent bulb and outstanding life expectancy (in excess of 50 000 hours!). They're harder to break too.
LED torches seem to have gone from strength to strength in the UK over the last few years. Although LED lights aren't a silver bullet for our lighting requirements, they certainly hold some serious promise - especially for developing countries where energy is scarce and often reliant on battery storage.
20 Feb 2008
Duncan, regarding your point 3. The mercury in CFLs is an important consideration. There is an excellent description of the environmental and energy issues surrounding CFLs on wikipedia, here: http://en.wikipedia.org/wiki/Compact_fluorescent_lamp
Hope that helps!
19 Jun 2008
We have CFL lights in our kitchen to replace the 13 GU10 downlights.
They give a HUGE power saving but do take a while to warm up and arent quite as bright as we'd like - about 25-30W equiv.
LEDs are still very expensive - even importing direct from China. There are very ew IF ANY places you can go to see them before buying.
Also they dont work with dimmers.