Originally Posted by echinatl
You mentioned that the city bypassed potential electricity savings when they upgraded 25 years ago by upping the wattage to the same wattage that the previous lights used (same wattage, but more light), and then you mention that the city is on track to make the same mistake. Could you tell me what the wattage is for the lights pictures in the article? It's really hard for me to believe that the new LED lights use anywhere near as much electricity as the old lights, no matter how bright they are.
i posted a response to this on reddit, but it's generally the same subject, so please forgive me for copy-and-pasting
"Keep in mind that street lamps are not incandescent bulbs. HPS lamps, which are the current technology, give out about 100 lumens per watt, which are what LEDs generally perform at. The problem is that most of that light is scoptopic, meaning it only stimulates the rods, not the cones, in human eyes. The energy savings come from the increase in photopic, or normal, light that LEDs put out. So to say it's an order of magnitude more efficient is not entirely true.
If Atlanta decides to install LED fixtures that put out more lumens (which do not distinguish between photopic and scotopic), they will indeed consume more energy than the current fixtures."
Also you touch on induction lighting, and note that the city hasn't given reasons why LED was chosing over induction. You don't need the city to comment on the why, because induction lighting flaws are widely known. Induction lights contain mercury (complicating disposal), and generally reach 65% brightness after 60,000 hours (most LED's used in street lighting reach 70% brightness after 100,000 hours). This is the reason they are so bright to start, because they will dim. If induction lighting was used it would also be really bright in the begining.
Early on induction lighting was much cheaper, but there have been faily dramatic advances in LED tech over the past 3 years which can give them the edge. I'm not saying LED wins over induction every time, but they're so close it's kind of a wash now.
i generally like induction lights because they look nicer. also, there have been advancements in the induction lighting field; however, they have not made it to street lighting yet. one example is tesleon technology, which bosch helped developed— they have increased lumens per watt to over 100, and have drastically reduced the dropoff in brightness. another example is the 'finally' light bulb company that is introducing induction bulbs for home use later this year.
i don't think induction technology is over yet, but it seems to me that neither technology has really reached its potential yet. it could be that replacing lights at this point is jumping the gun; perhaps we could get lights that are much more efficient than they are today in another 5 years.