Friday, December 14, 2007

Going Green: Vampire Devices and Zigbee

The xchange magazine article titled Telecom's 40 Shades of Green that I referenced on Wednesday includes a small section on "vampire devices". Vampire devices (also referred to as parasitic devices) do not have off switches and include products like DVD players, recorders and game systems. Have you ever walked around your house at night, counted the number of LEDs glowing in the dark and thought about the amount of power they were sucking up? Wouldn't it be great if you could turn some of them off and save a little power? It may not be just a "little power" - the U.S. Department of Energy estimates 5% of all electricity used in the U.S. is consumed by devices in standby mode and predicts this will increase to 20% by 2010!

One technology that has some energy saving potential is Zigbee. Zigbee is a Wireless Personal Area Network (WPAN) technology based on the Institute of Electrical and Electronics Engineers(IEEE) 802.15 specification. Zigbee operates at 868 MHz, 902-928 MHz, and 2.4 GHz and allows devices to communicate up to around 50 meters away at up to 250 Kbps. Zigbee was designed to maximize power - battery powered devices using Zigbee can sleep for hours or days. According to the Zigbee Alliance, ZigBee is the only wireless standards-based technology:

- that addresses the unique needs of remote monitoring & control, and sensory network applications.
- that enables broad-based deployment of wireless networks with low cost, low power solutions.

- that provides the ability to run for years on inexpensive primary batteries for a typical monitoring application.

The ZigBee 1.0 specification was ratified in December 2004 and we are starting to see Zigbee products come to market. Greenswitch, a wireless energy control system company, has a good video clip from Ed Begley, Jr's show Living with Ed posted here. In the clip Ed describes how the Greenswitch's Zigbee system can be used to control light switches, wall sockets, air conditioning, heating, etc systems. You'll also find 6 short videos on the Greenswitch site describing a step by step home Zigbee system installation.

Update, 12/18/07:
Mike Q sent along a link to a great Vampire Energy diagram that estimates how much energy is being comsumed by common devices when they are in standby mode. Here's the link:

Thanks Mike!

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