USB To Power Home Lighting?

Power delivery over a USB interface has been a frequently discussed subject on this blog, since I first called USB the Universal Supply Bus back in 2006. And the story keeps evolving! USB 3.0 gives us not only the 5Gbps data speeds, but up to 100 Watt (20V, 5A) of power too. At this year's CES (back in January 2014) DisplayLink and ROHM Semiconductor demonstrated a universal USB dock capable of charging a laptop via the USB Power Delivery standard interface rated at 100W (10x what is possible today with USB 2.0).

While this will make a 1-cable universal docking come true, the 100@ USB Power Delivery potentially has much further reaching potential. Such as being a standard in Home Lighting.

Yes, your home may soon be running a USB bus to the lights. While 100W for lighting may not seem a lot, it actually is. We've been used to judge 100W by what a single incandescent or halogen light bulb can consume. But they are things of the past. LEDs are typically 10x more efficient. So 100W for LEDs is what 1000W was for incandescent lamps. And that is a lot!

Standard electrical wires are capable of carrying up to 15 Amperes. At 110V this is about 1500 Watts. At 20V it is 300 Watts, so switching from 110V AC to 20V DC, we can run 300W worth of LEDs over the same wires. Getting rid of transformers in every LED lamp (think how much copper and heat / bulk can be saved!). Really powering LEDs with 110V AC (or 230V AC in Europe) is a stupid idea.

Also it is much simpler to make backup power supply rated for 20V. It would be just a couple of cells. With such backup, demand / response actions, reducing the load on the grid during peak times would be much easier to implement. So it may happen your 20V DC lighting system will be sponsored by your electricity provider. There are already companies working towards this vision: NuLEDs (http://www.nuleds.com/), LumenCache (http://lumencache.com/), Redwood (http://www.commscope.com/Solutions/Enterprise-Solutions/Intelligent-Building-Solutions/Intelligent-Lighting-Solutions/). But all these systems are proprietary in a way. USB Power Delivery, with a potential to become a widely adopted standard, can change the landscape of Home Lighting.