There has been much talk about regerative braking on PF lately. With that in mind, this article in today's Washington Post caught my eye. It talks about Otis Elevator's newest design which the article claims is 75% more efficient than conventional elevators. http://www.washingtonpost.com/sf/br...energy-efficient-elevators-are-imperative/#!/ How did they do it? The (non technical) article says via improvements in lighting (I guess LEDs), less friction in the cables due to cable design, and regenerative braking. I would love to learn what fraction of the savings came from reduced friction, but the article doesn't say. Note that this reganerative braking scheme has all the advantages. The motors, and the drive electronics are needed anyhow, and the load to be served by regenerative power is within the building. The energy does not need to be stored, nor negotiated for sale to a third party. Most interesting is a bar graph showing where the energy was spent in the newest elevators compared to conventional ones. The savings in lighting and drive power are obviouis. But control systems dissipation actually increased, and now appears to account for 2/3 of the energy consumption. I smirk at the irony, becuase that opens the door to future critics who might attack the wasteful smart control systems as energy hogs. You and I know that this is a good thing, but politics does not follow logic. What about Moore's law? Be careful. The smart microchips will not be dissipating all that energy, it must be the high power electronics. I don't think Moore's law applies to power electronics. However, improving the efficiency of power elecctronics might be a fruitful field of reasearch in coming decades.