LED vs. CFL vs. Incandescent

This article I read on edn.com, while it contains nothing I haven't read elsewhere, is a nice summary of the whole migration toward LED lighting. I hope to see LED lights that approach the efficacy (efficiency in terms of lumens per watt) of a good fluorescent light (around 100 lumens per watt). One named in the article was getting closer (about 80) and I've heard of laboratory tests of prototypes that are in the neighborhood of 150 (yes!).

I still want to see an intelligent way to retrofit existing dimming bulbs with dimmable CFL and LED fixtures. I think a bidirectional communication protocol between the bulb and the dimmer might be a way to do it, perhaps over the existing power line. The problem with that method is the extra cost, complexity, and reliability of adding that hardware to the bulbs and the dimmers. A dimmer would probably need to detect the connected load, and either use traditional dimming (for regular bulbs) or leave the power fully on and communicate the dim level, letting the ballast at the load control the brightness.

Perhaps the communication can occur by doing phase cutting, much like regular dimming, but use a 95% brightness level for one digital level (zero or one) and 100% brightness for the other value, and use, in effect, a serial data stream over the power line.

Long term, however, low or medium voltage DC power to the lighting loads, with digital control at the point of load, would be more efficient and have fewer points of failure than the current methods.

Just a few random thoughts. I hope to come up with a more coherent post in the near future. It's been a very busy few weeks, so I haven't been able to write a more organized, thoughful post than this.