enkitec said: > An alternative to CFL and LED is emerging: > http://www.vu1.com/ > http://www.vu1.com/ESLupdate/default.htm Russell McMahon says: It looks to have potential BUT it is nowhere as near a complete and cut and dried solution as they would have you believe. Quite a lot of their video statements come close to lies. They are certainly selling FUD. Whether they get to sell bulbs is to be seen. I'm not a CFL apologist, but when somebody attempts to mislead re their characteristics I get interested. I am to some extent an LED apologist, but am mainly interested in seeing accurate technical comment made. This comment is probably longer than the issue is worth for most people - but lighting technologies are of special relevance to me at present. By all means show me a new 90% efficient means of converting electrical energy to broad spectrum light energy :-). ___________ STOP PRESS: Written last: Just found spec here: http://vu1corp.blogspot.com/ These show some very strange interpretations of the claims made: > 30 lumen/Watt TARGET is surprisingly low Dimmability to 20% (= full dimmability?) Life > 6000 hours (compare with LEDs from reputable 'Big 5' makers) Instant on = < 250 mS (!) No XRay, No UV Wattage < 20W. > 50% less heat than from 65 Watt incandescent. [That claim may have come from bad proof reading - I'd certainly hope so]. CRI of 90 is good. _________________ - THEY say that mercury content is the main CFL problem. It's been suggested that when you consider the mercury content of a good quality CFL bulb against the mean mercury output of power generation required to drive equivalent incandescent bulbs then there is a significant mercury reduction. ie coal burning and other generation systems releases mercury into the atmosphere. Coal is not the world's most shining energy source at present :-). I don't know the true result BUT this shows that there can be more to evaluating such claims than may at first be apparent. As an infant I, and many other babies, bit a mercury thermometer and swallowed the mercury. Presumably it was subsequently "eliminated". No known harm (or it may explain me now ;-).) Broken CFL cleanup drill is bizarrely severe. comforting but beyond realistic. Do it by all means if you care. BUT a fully shattered broken CFL while running would be best 'avoided" till the mercury condensed. - Their claims re colours, colour change with time, light quality and similar between CFLs, LEDs and ESL are extremely suspect. You can make poor low life poor spectrum CFL and LED products. Or, rally very good ones. ESL relies on phosphor luminescence and their claim re better spectrum would need to be checked. A modern phosphor LED DOES have a poor two peak spectrum due to the mixing of the LED blue with phosphor yellow - but better can be achieved. Recent moves to higher power RGB LEDs in commercial use and you could easily go to 4 emitters if desired. - The needs for lumen maintenance and CRF matching are very well known by the lighting industry and can be addressed as well as you want to pay for.. So - If ESl was super cheap and super efficient then the need to move towards premium CFL & LED solutions may affect competitiveness BUT the claimed target ESL efficiencies are extremely modest compared to either LED or CFL. A good higher wattage CFL will run in the 70-80 lumen/Watt range. A good tube fluorescent exceeds 100 l/W. A good modern high power LED is 100-110 l/W and the best LEDs (like the ones I am using :-) )are in the 120-140 l/w range. ESL says " ... For energy efficiency,Vu1 is targeting to be two-thirds more efficient than the incandescent bulb..." which is extremely low by LED or CFL standards - an incandescent is in the < 20 l/W range so they are aiming at 30-40 l/W - The above makes their claim about the basic technology of LEDs making them energy inefficient, and thus hot, so much hot air. A top class white LED currently radiates about 1/3 of its energy input as light !!!! and this figure will increase/ LEDs do indeed employ large radiators and do have heat dissipation challenges, but the spin put on this makes the fact seem different than it is. - They provide a list of CFL and LED 'disadvantages' but mix the two together and fail to note that LEDs effectively do not have twp of the 3 listed. ie LEDs have instant startup and for practical purposes are 100% dimmable. (ie it doesn't matter what the LED does to produce the optical result - it's what you see that matters. A LED can be dimmed as deeply as you wish by PWM ing.) They also imply that LEDs have a massive recycling problem and that ESL somehow doesn't. Current compact high energy LEDs have substantial radiator structures - but these can have net disposal value and do not need to be a recycling overhead. They also imply that LEDs have a mercury problem. - The ESL unit *apparently* uses a high temperature glass envelope to radiate unused energy, but one wonders about the energy transformer which produces the electrons which drive the electroluminesence. - And the cost of what probably involves driver electronics (presumably with no mercury content). - And one might wonder whether there is an actual electron beam in there and, if so, what sort of voltages are involved and whether XRay generation may be an issue. (I don't know). - The video footage of light bulbs in production was impressive - but the prototype light on the bench did not seem to match the production images wrt completeness or what you'd expect to see in a demo - I suspect the two may have been 'creatively linked'. And more ... . So: ESL MAY prove to be a promising lighting technology and MAY have advantages over LED and CFL, but, given all the issues I've noted, if I was an investor I'd probably be looking elsewhere at present. Russell McMahon -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist