EPRI’s Chhaya: Smart EV Charging Ready to Launch

By · August 14, 2013

EPRI’s Chhaya: Smart EV Charging Ready to Launch


Getting grid operators and automakers – powerful industries that have historically been staunchly independent with little reason for dialog – to work together on the integration of plug-in electric vehicles (PEVs) into the smart grid has been the mission of Sunil Chhaya, the senior manager of OEM PHEV programs for electric transportation at the Electric Power Research Institute (EPRI), since 2007. I spoke with Chhaya to get a preview of his upcoming talk on the topic of the smart charging of PEVs at Plug-In 2013. The annual Plug-In event, which this year runs from September 30 to October 3 in San Diego, provides a unique opportunity to connect with the leading figures in the PEV, utility, and charging infrastructure sectors. Below is an edited version of our conversation.

Navigant Research: Where is vehicle charging occurring and why is it important to develop technologies that can make it smart?

Sunil Chhaya: Both EPRI research and actual operational data from automakers indicate that 60% to 70% of charging occurs at home, which means that anything that you can do to shift load when the cars are parked overnight will be beneficial to the power grid. While low-power charging at 120 volts (or 3 kilowatts or less) is not a significant burden, at rates above 4-6 kilowatts, the potential impact on local power distribution gets interesting. At 8-10 kilowatts, it becomes necessary to pay careful attention to how it is managed. This means you need to have direct communications between utilities and the vehicles. We are working on how to leverage technology that exists on the utility side and how to connect that to telematics and other systems in the vehicles at as little incremental cost to the vehicle owner as possible.

NR: What information is it necessary to share and what standards are being developed to enable the power grid and vehicles to communicate?

SC: We have been focused on enabling sharing of the electricity rates (the cost to customers), as well as the signals from utilities that can enable peak load reduction to avoid distribution system stress or critical peaks. The Society of Automotive Engineers (SAE) has been active since 2008 in creating a family of recommended practices around information and method of communications, in the form of the J2931 (HomePlug GreenPHY) and J2836/J2847 family of standards. There has been coordination between SAE, JARI (Japan Automotive Research Institute), and IEC (International Electrotechnical Commission) that will allow harmonizing of global standards. In terms of physical media, we have been working on power line communications (PLC) and the HomePlug GreenPHY standards. HomePlug GreenPHY is already starting to happen in PEVs in the United States and Europe, as every PEV (whether charging from an AC or DC supply) in Europe and every company that offers DC charging in the United States on its vehicles has to include it along with the SAE Combo Plug standard.

There is also interest in taking advantage of the Smart Energy Profile 2 (SEP2), which uses Internet-based protocols so that the communications protocol can ride on any Internet network, whether it’s wired or wireless, including Wi-Fi, Ethernet, HomePlug, and ZigBee. SEP2-compliant equipment can connect using any Internet connection, including cable broadband or wide-area wireless, and ultimately down to the PEV.

NR: Can a single connection be used for all grid-to-vehicle communications, or are there benefits to using one system or another?

SC: The utility industry is diverse, and in many cases, utilities are just getting started in implementing many of these standards. This means that a one-size-fits-all (for a single communications path) approach is not practical. We recommend an all-of-the-above approach that is open standards-based, so that utilities can choose whatever interoperable technology works best for them that can be bridged to their existing technology. The customer doesn’t care about the underlying technology; they just want it to work.

NR: What has been the progress to date on developing fully functioning smart charging systems?

SC: We are now in our sixth year of working with car companies on pilot projects. We have been working with Ford, GM, and Chrysler on implementing the standards-based technologies. Soon we will begin working on a large pilot with 300 PEVs in a commercial fleet that is implementing SEP2 and HomePlug GreenPHY and connecting to AMI (advanced metering infrastructure, used in smart meters), broadband, and telematics systems. We are starting a project with eight of the major automakers to unify the communications approach across the industry.

NR: Most EV supply (charging) equipment (EVSE) is already smart, so why is communicating with the vehicles necessary?

SC: Utilities like EVSE because they are fixed and are easy to manage by utilities or anybody. But a link is missing here – this ignores the customer, and the customer is the one who has to drive someplace. The system has to have the customer’s input so that charging can occur in a timely manner while factoring in grid stress. Some charging stations allow for immediate charging, which may require customers paying a higher electricity rate. The simplest approach is to let the customer set up his/her preferences in the car. We are seeing most automakers enabling this feature.

NR: Are utilities ready to enable the smart charging of any PEV?

SC: Utilities have had traditional pricing tariffs for PEVs and the demand response programs primarily targeting commercial and industrial (C&I) customers. We are now starting to see action, as requests for proposals are being issued for developing load management programs based on open standards such as OpenADR. Many utilities have been piloting smart charging for some time. They are learning what scales, what is cost-effective, and what gets the job done. Utilities are taking a holistic approach, determining that perhaps the responsibility of whether only to manage just the charging of the car, or also manage consumption at the household level in the form of the kilowatts that are being consumed. They are still developing the programs that enable the customers to have the final say in how this is orchestrated.

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