GFCI has no influence on backfeeding, except when a ground fault triggers it and it disconnects. I agree that L1 power is sufficient for charging EVs most of the time (I am 99.9% L1 charge user) My only concern is if the grid support can be delivered through L1, in other words - can an EV give a meaningful support to the grid if it is limited to 1.5kW? The other concern is that most L1 outlets are shared (I mean: more outlets on the same circuit breaker) whereas a backfeeding generator preferably is on its own breaker to avoid that you can draw power power from the *other* outlets than that the breaker is protecting - there is a small risk of burning up the wires without the breaker triggering if the backfeeder if giving a steady stream of power (most notably this occurs with solar, that is why an inverter is typically always on a separate circuit with no other loads connected to the same circuit). Since I have no clue about the typical power levels involved with grid stabilization, I leave my first concern unanswered - hopefully someone else can contrtribute meaningfully to that one.
Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: cwa...@proxim.com Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 -----Original Message----- From: EV [mailto:ev-boun...@lists.evdl.org] On Behalf Of Haudy Kazemi via EV Sent: Friday, June 06, 2014 10:44 AM To: Robert E CIV USNA Annapolis Bruninga; Electric Vehicle Discussion List Subject: Re: [EVDL] V2G at L1 is practical On 06/06/2014 09:41 AM, Robert E CIV USNA Annapolis Bruninga via EV wrote: > Subj was: RE: [EVDL] EVLN: E-school-buses$aveschooldistrictsmillions > >>> I just think the fluctuation in loads is substantially more predictable >>> than the number of vehicles plugged in at any one time. > Which trigger my 2 cents: > > V2G will never be practical unless vehicles are plugged in all day. > And if they are pluggedin all day, then they only need 120v L1 15 amp > service. > Already, we know that 97% of charging-at-work is satisfied with L1 charging. > > So in order for V2G to be able to take advantage of all the demand-load of > millions of EV's and/or to also take some charge, the focus has to be on > low-cost L1 approach, not expecting EVERY EV (by the millions) to have a 50 > amp L2 service and to sit there blocking it all day long. That is simply > unsustainable at the quantities needed. Millions of L1 outlets is possible > and practical. > > But providing at least demand-response at every L1 outlet in a parking lot > is as easy as hooking up a water-heater or Airconditioner utility disconnect > and giving the utility immediate control over that load during the day. > This is not only dirt cheap, and practical, it eliminates the #1 issue with > V2G (NFMB, Not From MY Battery!). > > Sure it gives up 50% of the promise of V2G (and all its NFMB issues) but the > other 50% is the low hanging fruit, that is PRACTICAL at SCALE is simply L1 > charging-at-work with demand response control of the outlets. > > Bob Bruninga, PE > EVADC > V2G is a type of backfeeding; 120v L1 outlets protected by GFCIs probably won't work very well for this, but dedicated 120v outlets exempt from upstream GFCI could. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
