When plug-in vehicle (PEV) companies went looking for a way to talk to devices in the home, they found one right on the wall.  Automakers have begun to adopt the HomePlug GreenPHY standard, which enables smart devices to communicate with one another over power lines. 

Recently, Ford and GM joined European companies Audi, BMW, Daimler, Porsche and Volkswagen in pledging to support HomePlug GreenPhy in future vehicles.  Once compliant chips are embedded into vehicles, powerline communications (PLC) will enable them to share information about their required charge rates, their unique vehicle ID, the battery’s state of charge, and when a full charge needs to be completed.  Using HomePlug Green enables these messages (as defined by the SAE, IEC and other standards groups) to be sent to electric vehicle supply equipment (EVSE) or through a standard 110v outlet and to smart meters or other devices in the home.  Once in the home, the information can be shared with any other device through a variety of networking communication options, such as via Zigbee or WiFi. 

Benefits of the technology were outlined during November’s HomePlug conference in San Francisco.  Since each vehicle will have a unique ID, PLC can be used to bill the vehicle owner’s utility account for their electricity use without the need for a sub-meter or an RFID card.  So no more worries about leaving something in the tip jar if you want to plug in at a friend’s house, and multi-unit dwellings will be able to charge each EV owner without adding infrastructure.  HomePlug GreenPHY, which is a leaner but compatible subset of the HomePlug AV standard with a few extras added in, will enable buildings to manage their loads more effectively by understanding which devices are consuming power, and in cases of high demand, slowing down charging while keeping essential devices fully powered. 

This standardization has a downside for EVSE companies, which have been silent since the standard first came about a year and half ago.  (At the conference I asked the EVSE companies in the room to raise their hand if they had announced HomePlug GreenPHY support; no hands went up.)  Setting up their own authentic and payment systems has been integral to the business model, and HomePlug makes some of that intelligence in an EVSE redundant, though they can incorporate technology into their products and pass along the data to the homeowner or utility. 

In the long run, you can expect some home energy management companies and home area networking companies to incorporate the PEV information into their management services, so the vehicle’s energy history and costs can be displayed via the web or any other interface.  Theoretically, the HomePlug GreenPHY standard could be used to download music or movies to the car’s infotainment system during a charging session, should the automotive OEMS choose to go that route. 

Currently automakers are waiting for GreenPHY chips that they can test to put into vehicles, as so far only chip companies Qualcomm Atheros and Greenvity Communications are developing GreenPHY chips.  We should expect more of their competitors as well as EVSE manufacturers to get on board soon, and for automakers to have chips in their cars by the 2013 model year.