Comments on: An Inconvenient Truth: A Call to Action

By: Craig Hughes

Craig Hughes — Wed, 21 Jun 2006 19:57:45 +0000

The spectrum of the current lights is not bad -- the only real problem is total lumens, but that's improving quite rapidly: http://gizmodo.com/gadgets/gadgets/ultra-high-efficiency-led-created-182241.php Of course, the other important element beyond lumens/watt in a single LED is how tightly you can package them and not have the whole thing melt. As for availability, that's also definitely an issue today. The LED array manufacturers are clearly going after the commercial/industrial markets first, with custom fixtures and not just simple bulb replacements. But you can start to find bulbs online now, particularly the low-voltage replacement bulbs. And since they just basically don't burn out, having local availability at the hardware store to get replacements as they burn out is less important. When they start getting dim, get online and place your order. Heck, get ground shipping instead of next-day, cos the bulbs will still be working next week.

By: Ryan McIntyre

Ryan McIntyre — Wed, 21 Jun 2006 16:43:20 +0000

Craig, thanks for the info on the CF bulbs startup power draw, I wasn’t aware of that. I too plan to put LED lighting in my house as soon as it is bright enough (and hopefully the spectrum will be more pleasing too).
Clearly LED is superior to CF in terms of lifetime and lower power draw, and is about 10 times less power-hungry than typical incandescent bulbs, where 90% of their energy goes to wasted heat output (which then drives up cooling costs). The only reason I didn’t mention LED as a lighting option is they aren’t yet widely available. My local hardware store stocks plenty of CF bulbs, but no LED bulbs.

By: Andrew Fife

Andrew Fife — Wed, 21 Jun 2006 07:28:12 +0000

Funny, I saw the movie recently also but I felt it did a terrible job of providing the audience with action items. Why wait until the credits are rolling to start making suggestions and why use such vague suggestions as "drive less." People are not going to drive less as a result of the movie, but more specific advice such as "consider purchasing a car with 30+mph fuel economy" might affect someone's next purchasing decision. Also, the movie gave me the distinct impression that its ultimate goal was launching Gore's next political campaign. Anyway, I've written more of my thoughts on how the movie could have made a stronger impact here: http://andrewbfife.blogspot.com/2006/06/al-gore-creating-more-convenient-truth.html

By: Craig Hughes

Craig Hughes — Tue, 20 Jun 2006 23:13:07 +0000

And on the cars topic. Why is there no such thing as a diesel (about 2x the efficiency of gasoline) hybrid (2x the efficiency of throwing away your breaking energy) station wagon (about 1/2 the mass of the typical SUV) from any manufacturer in the world?
As a bonus of course, a diesel engine would mean that you can provide primary power to it from fully renewable energy sources, like palm oil.

By: Craig Hughes

Craig Hughes — Tue, 20 Jun 2006 23:09:05 +0000

My understanding is that compact fluorescents are close to a wash in most home-use scenarios, due to a high startup current draw which then goes down when the starter shuts off; since most domestic lights are turned on, left on short time periods, then switched off again (unlike, say office lights, which tend to run longer), replacing regular incandescents with compact fluorescents really doesn’t net you very much in a residential deployment. Though the bulbs’ lifetimes is generally a lot longer than regular incandescents, though again frequent on/off will wear out the started before the bulb itself dies.
By contrast, LED-based bulbs seem to be really good. Better steady-state consumption than compact fluorescents by about 2x lumen-for-lumen, and they don’t have the hideous startup power draw. They also have great lifetimes, fading over time rather than burning out, such that arrays from companies like Lamina Ceramics last about 50,000+ hours to 50% brightness. High-end CFs are typically rated for about 10,000 hours MTBF.
They’re not terribly easy to find right now in “white” colors, but plug-in replacement bulbs for both regular screw-in and low-voltage standard sockets are starting to appear. They haven’t yet been able to get the bulbs up to the higher-end brightness levels, so you’re limited to the equivalent of about a 60W incandescent or so (less in the smaller low-voltage packages). We’re designing the lighting in our house to ensure that’s not a problem, even if they never manage to figure out how to get brighter. It’s pretty rare that you ever need more light than a 60W incandescent bulb in a standard fixture indoors.
Oh, and as an added bonus, the sigma on the MTBF (or MTB 50% dimness in this case) is nice and narrow, so you won’t likely have many bulbs getting super dark before they’ve run for 50,000 hours, where with CF bulbs, you likely will have some which burn out inside a year and need replacing.
Note that most of the above is based on only partial information — it’s very hard to actually get real data on much of this stuff. But here’s a good link:
http://www.nema.org/prod/lighting/solid/upload/NGLIA-fact-sheet.pdf
Page 5 is the good stuff comparing fluorescent to solid state.
Othere environmental concerns: mercury in the CF bulbs means that you need to take special care when disposing of them. I don’t have anything which tells me what all nasty stuff might be in the LED arrays which doesn’t want to end up in landfill/water supply somewhere, but I bet there’s some decent amount of tasty rare-earth goodies in there. But in any case, coal-fired power stations are by far far far the largest emitters of mercury in the environment, so concerns about mercury will be dominated by just reducing power consumption.
Other generic concerns:
CF bulbs produce non-insignificant noise on the power lines. Depending on what else you have hanging off your home grid, you might need/want to filter. If humming switches bother you, CF will possibly be annoying if deployed house-wide.
CFs can take about 30 seconds to reach full brightness, which is annoying in places like bathrooms.
CFs have ugly colored light. This is remedied somewhat by having a decent phosphor blend on the bulb, but these bulbs generally have worse power characteristics, and the 30-seconds-until-fully-on aspect means that even these specially-coated bulbs only generally really look good once they’re fully on.
CFs flicker at 120Hz, again, this can be mediated somewhat by painting more/different phosphors on the bulb, at the cost of more power loss, and to my mind, even the “good” CFs still flicker unacceptably if they’re the only light source.
You can’t dim a standard 2-pin CF bulb. Dimmable CFs generally depend on a fixture which is purpose built for them.