As a participant volunteer in the Pecan Street Project – a smart grid demonstration project which includes Mueller, Austin in it’s five year study, I invited some folk into my home tomorrow to test ZigBee. Until today, I had no real idea what that meant.
In technical terms it’s a “specification for a suite of high level communication protocols using small, low-power digital radios based on the IEEE 802.15.4-2003 standard for Low-Rate Wireless Personal Area Networks (LR-WPANs)”. Thanks wikipedia. What that means is alarmingly simple – it’s a standard way for your light bulb to talk to a light switch, no matter who has built each.
“Isn’t that what wires are for?” I hear you ask. Well, in a traditional sense, yes. If you want to do something a little more fancy then you could use one of the ZigBee standards – e.g. ZigBee home automation. If this is all a lot of gobble-de-gook at this point, let’s look at an example.
Say you want to monitor how much energy is being used by a specific power outlet / plug socket. Which you may very well want to do if you’re trying to pinpoint energy usage in your home and find ways to reduce unintended or unwanted usage. You attach a ZigBee Smart Energy plug socket from one manufacturer into your electrical supply. It sends information to a small energy portal which also collects electricity tariff information from your utility provider. You see a simple chart showing usage and cost information for each socket on the portal. Simple!
On your portal, you notice that you’ve inadvertently left the lights on in three rooms, which your ZigBee Home Automation occupancy sensors tell you are empty. You tap the portal and the ZigBee controlled lights are all turned off. Or say you notice that you’re currently in peak summer pricing time from the utility company, and you have all three zones of your HVAC system set to cool, and your plug-in hybrid car is about to charge. You might elect to turn off cooling in the downstairs portion of your home as everyone is hanging out upstairs, and draw energy from your car rather than charging it to avoid peak tariffs.
(note: Austin Energy right now doesn’t have different Time Of Use energy rates, though it does have different tiers of energy pricing – different prices per kWh for different bands of monthly consumption. Both Austin Energy and the Pecan Street Project are investigating Time Of Use pricing).
So when I started this article, I was talking about a set of high level protocols called ZigBee. They allow device interoperability from long battery life devices connecting to one another over a short distance, such as in a building or home. I then got a little carried away talking about using energy from your car to power your HVAC, for one simple reason. It’s like having the internet for the devices in your home. Which kind of excites me.
The article here represents the views of the author and not Austin Energy, The Pecan Street Project or pretty much any one else.
Garreth Wilcock is an Austin EcoBroker®
Specializing in: New Green Homes.