Feedback: Reversing the Electrical Flow

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By earsz (Contact - View My Woyano)
Published Sun 29 Jul 2007, 220 Views, 5 Comments

by Larry E. Hall
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

OK, you're feeling really cool and smart with your purchase of a plug-in hybrid-electric vehicle (PHEV). Your daily round-trip commute to work is barely 30 miles so, recharging the batteries overnight gives you some change back from a ten dollar bill for the weekly cost of electricity. Plus, since you drive entirely on electric juice, there are zero emissions coming out the tailpipe.

Wowzer, what a feeling! But wait, there could be more euphoria in the offing.

What if the local power company was willing—maybe even anxious—to pay you to draw some of the stored energy from your PHEV's batteries while it was parked during the day? Hey, that would reduce the cost of operating the car even more.

That's exactly what Professor Willett Kempton of the University of Delaware and his colleague Dr. Steven Letendre from the Green Mountain College in Poultney, Vermont, came up with in 1966.

Called vehicle-to-grid (V2G) technology, the idea is to take advantage of the electrical storage capacity in the vehicle's battery during hot afternoons when demand is highest and most costly to avoid blackouts. During these periods, energy is worth several times more than overnight when vehicles recharge. It is also possible to provide power to a home or businesses on occasions of high electricity demands to avoid high energy prices and help prevent outages.

Kempton and Letendre's idea isn't just a theory presented in a technical journal. In April, California utility Pacific Gas and Electric Company showcased the first-ever utility V2G technology demonstration. The prototype PHEV was a traditional Toyota Prius with an added Lithium-ion battery. PG&E reversed the flow of energy from the vehicle back to an electrical outlet, then ran several lights and appliances to show how V2G could benefit its customers.

The really big potential of using V2G, however, will come from integrating the technology with renewable energy and thereby reducing harmful emissions. During times of maximum demand, electrical utilities have to buy power from expensive and less efficient fossil fuel power generating sources.

PHEVs will charge their batteries at night when energy is inexpensive and is generated with a larger percentage of renewable resources. When demand is high the next day, instead of turning on a fossil-fuel based generator, the utility can purchase the renewable energy stored in the vehicle batteries.

There are numerous hurdles in the path of V2G, not the least of which is the cost of developing and integrating the technology into the automotive and electrical generation industries on a wide scale. But, because V2G has the potential to radically change both the utility of vehicles and the ability of cities to meet peak electrical demand with significantly lower costs while reducing harmful emissions, don't be surprised if the hurdles are overcome sooner than later.



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Category: News, General
Tags: environment, electricity, utilities
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    5 Comments

  1.  
    jbravo ~ 10 months ago
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    I had heard of this idea with respect to battery banks in solar power setups. I never thought of using the batteries in electric vehicles, though. Awesome idea! Work places and comsumer businesses should eventually have the capability to plug these things in. That way, benefits can be achieved when you're away from home as well. Of course, you'll have to have a way to limit the amount of power that may be drawn from your batteries so you can still get home!
    [ reply ]
    1.  
      clemmati ~ 10 months ago
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      I'd heard of it in the context of solar power panels; a surplus can be stored in batteries or sent to the National Grid, and there's been some talk of its being sold to the National Grid. This idea seems similar -- and it makes an awful lot of sense.
      [ reply ]
      1.  
        earsz ~ 10 months ago
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        Locally, homes with utility power lines and with solar panels that produce excess power may feed that power back to the utility and receive a credit against the monthly bill. That in turn may offset some of the utility's needs during peak demand periods. The process would be the same with a vehicle, except that ultimately there could be a lot more vehicles than houses feeding back into the system.
        [ reply ]
        1.  
          earsz ~ 10 months ago
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          I somewhat misspoke. The way it works is, oversimplifying: the residential solar power supply (all or part but consistently) is fed to the utility, and that amount is credited agaisnt the total electricity used, reducing the bill. At present, cash subsidies from the state of Arizona, the feds and at least one local utility (there are two serving this area) will reduce the cost of a $21,000 installation to a net of $9,000. Recovering that $9,000 through electricity savings is figured to take 23 years.
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          1.  
            clemmati ~ 10 months ago
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            Ah -- I didn't know it happened there. There are subsidies here too and the period of recouping the outlay is similar.
            [ reply ]
            1.  
              22 votes thumbs up thumbs down
              This is my two cents...

                 
              Hey you know AdGuy always gets the last word! ;)

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