Being in the Energy field I get all the sales people knocking at my door. The new item up on the block is LED lights. They have been used a long time now in flash lights and is not a bad application. Traffic signals is the current fad.
On traffic signals significant savings are being made we can reduce a typical four way crossing from 2800 watts to 250 watts. The issue we see in the new technology is the real lack of heat to de ice them in the winter. Southern Ontario is the least effected by this as we get far less snow then our brothers to the north. I do not know if many norther cities are do mass conversions. One proposal I put to the manufactures is the installation of small heater wires like the ones used in a car rear window. The issue is to know when snow is covering the lamp head. I am sure they will come up with something.
More recent say since Dec 2007 are the street light proposals to place leds for the yellow Low pressure sodium lamps. Again the fear of snow cover is an issue and more so with a street light then traffic signal. I have seen a few installations in the Toronto area but do not feel they are very cost effective as of yet. The issue is not the cost per lumen but the lack of light spread on the ground below. Far as I can tell one needs 3 for every 2 existing sodium light thus the cost is prohibitive as well as cosmetics.
I have been told buy the "experts" in lighting (Most seem to be sellers of light product!) that I do not know what I speak of. So to my delight I found this following study completed by the USA Department of Energy.
https://www.netl.doe.gov/ssl/PDFs/EmergingT...eetLighting.pdf
Main page where I found the study.
https://www.netl.doe.gov/ssl/techdemos.htm
So perhaps in time with some more new advances this technology will become more feasible. Till then we get yucky orange lights. FYI for you in the warm climates the yellow lamps are great aid in the winter as they light the road better for snow storm driving.
In your house I would recommend the led replacements for the metal halite lamps. They produce far less heat and use less energy but are very expensive still. I like them for under cabinet work as I have seen far to often scorch marks from metal halide lamps in wood furniture.
My two cents for what its worth.
We have some of the LED street lamps in our city being tested as to whether they want to switch all of them to the LED or to leave it at the yellow lights. I like some of the LED lights they have been coming out with. I am thinking of putting some under the counter lights in my kitchen to make better use of light in the kitchen itself. I am slowly replacing my lights in the house with those newer florescent type of lights instead of the incandescant bulbs of old.
Do you find the light distribution the same as the other fixtures and did the snow build up on them causing them to stay on? Sounds silly but these issues have been report in some cases.
I like the color of the led lights and I fully expect the costs of them to drop significantly in the next few years. I just ponder how much they will drop given the 40 000 plus hours they are given for a life span.