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Kevin Bullis is Technology Review’s energy editor.

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Thursday, April 02, 2009

GM Volt to Allow Smart Charging

The plug-in hybrid could communicate with utilities to optimize power use.
Credit: GM

In a conference call on Thursday, GM hinted that it will be implementing a system that will allow two-way communication between the Chevrolet Volt's battery charger and electric utility companies.

One of the big potential problems with plug-in hybrid vehicles (cars that can be recharged by plugging them into a wall socket) is that if they're ever widespread, and people plug them in all at the same time, it could overload the electricity grid.

But with the right equipment, plug-ins could actually be good for the grid. If the chargers had timers that put off charging until the wee hours of the night, the cars could make use of excess power-generating capacity on the grid. If the cars could communicate with each other, they could automatically stagger their charging, spreading out the load. And if they could communicate with utilities, they could charge when the utilities have extra power and stop charging if demand gets too high, helping to smooth out demand and prevent blackouts. There's even a plan eventually to allow cars to deliver power back to the grid to help with peaks in electricity demand. Such smart charging could make it possible to incorporate more renewable energy, by helping to make up for the variable nature of wind and solar power.

Tony Posawatz, the vehicle line director for the Chevrolet Volt, confirmed that the Volt due out in November 2010 can be programmed by owners to charge at different times. The other stuff will require more complicated equipment. Without going into details, Posawatz said that GM's OnStar system can allow for communications, making other equipment, such as smart electricity meters, unnecessary. At this point, it's not clear what exactly the OnStar system will allow, or what will be available with the first version of the Volt, but Posawatz said that case studies are being conducted, and he suggested, by way of a rhetorical question, that the system could communicate with utilities. That could allow for much of the smart charging that could help stabilize the grid. The possibility of cars delivering power back to the grid, however, will have to wait, he said.

Comments

  • Volt Demise
    So why would Obama tell GM to dump the Volt, and to remove the CEO who championed Lithion Ion batteries for the Volt?  When government takes over business, we're doomed.
    Rate this comment: 12345

    RD
    04/03/2009
    Posts:125
    Avg Rating:
    3/5
    • Re: Volt Demise
      um...he didn't tell them to dump the volt. He did say that their business plan wouldn't allow the company to survive long enough to produce the volt, but that's the result of losing over $80billion over the last few years.

      As for Obama asking the guy who lost $80billion to leave...look, whatever he was doing right with the volt was clearly overwhelmed by what he was doing wrong with the, um, WHOLE REST of the company. If the company dies, there is no volt.

      And since the US govt is now (or will be soon, not sure of purchase timing) a majority shareholder, the idea of a representative of a majority shareholder asking for the resignation of a CEO who has lost net worth and market share over his tenure as CEO, and is on a multi-year tear through $80 billion - well that's hardly unusual, is it? Isn't that exactly what you'd expect from an institution concerned about losing a large investment?

      The real surprise is not Rick Wagoner's resignation but the lack of resignations on Wall Street - but that's Geithner's doing, I suspect.
      Rate this comment: 12345

      cripdyke
      04/03/2009
      Posts:19
      Avg Rating:
      3/5
  • Don't make the cars stupid
    Communication between the charger and grid isn't going to make electric use intelligent-- it's communication between the car (or appliance like washing machine) and the driver that matters most.

    All this talk about smart grids these days seems excessively complex. Just put the charge control settings in the car-- not necessarily the external charger, so you can plug in anywhere. A dumb car would be like your battery charger-- you plug it in and it charges at full speed till full. Hopefully, GM, Toyota, etc. won't be that stupid. No communication is required-- just allow the car to keep track of the electric rate (or niceness) by time of day and the charger can turn on at the right times. When the car is turned off, the display could switch to an "add charge" menu, and the driver could press a button to activate charging if needed, and maybe indicate how long the car will be parked. There could be a default, e.g. wait until overnight unless a button is pushed. It's better to put this in the car instead of trying to get drivers to understand the intricacies of each charger. (I guess a control panel could be added near the charging port on the car, but it seems like reusing the inside controls would be cheaper.)

    If I were a GM designer I would try to get GPS a standard feature-- then the car would know if it's at home or somewhere else and that could affect the default charge (e.g. just enough to get home, or overnight if at home). A smart GPS could calculate how much charge is needed to get you home, then add that amount during the day then wait for overnight for a full charge. If the driver puts in the destinations and leave/arrival times, the car can work out peak use charging required. [If the car plugs into a high-power charger with some communication, then presumably an ID on the charger could indicate being at home, so a GPS isn't really needed.]

    The real issue with smart grid is standardizing the communication method. An internet connection would support whatever could be worked out, but for radio broadcast and 2 way communications (for second-by-second load control) a standard method really needs to be agreed upon. Patents and proprietary technology could be a barrier. The OnStar network could be a way around the standard communications, at least for GM cars, but how many proprietary networks are we going to have to deal with?

    Two way communication between charger and grid could eliminate some spinning reserve generation capacity. But 2 way communication isn't really needed. The utility could just broadcast a message like "Please try to reduce use by 0.1% over the next 2 minutes" then chargers, etc. could cut back by .1% or turn off with 1/1000 chance. The grid could measure the response, then ask for more after it senses the amount of variable load currently attached. When time-of-day rates change, there would need to be some transition times, e.g. "turn on with 1/10 probability" so all the appliances don't switch on at once when it hits 1am or whatever.
    Rate this comment: 12345

    carlhage
    04/03/2009
    Posts:27
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    4/5
  • charging stations
    Solar charging stations with shaded parking structures and a smart charger (http://www.coulombtech.com/)
    will prevent any grid problems.
    albert@solutionsforpower.com
    Rate this comment: 12345

    solar-guy
    04/06/2009
    Posts:1
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