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FUD in Great Britain

Discussion in 'Europe' started by GSP, Aug 27, 2017.

  1. GSP

    GSP Member

    Joined:
    Dec 28, 2007
    Messages:
    2,284
    Don't boil the kettle while charging your electric car because it will blow the fuse, National Grid warns

    Looks like another attempt to confuse the public and instill fears that home charging requires expensive service upgrades. This sort of BS is everywhere.

    Of course, there are many practical solutions to charge EVs with whatever your existing service is. No need to be afraid of making tea because your car is charging.

    Here in the States, I only use a single 240 V circuit to charge my Model S at 16 A. I have a timer to start charging at 10 pm, when the off-peak rates start. It is always nicey charged up in the morning.

    I have 200 Amp, 240 Volt single phase service at home (very common here) and could upgrade my 16 A charging circuit if needed, but it is not necessary.

    GSP
     
  2. arg

    arg Supporting Member

    Joined:
    Aug 22, 2012
    Messages:
    903
    Location:
    Cambridge, UK
    Yes, it's sad to see this stuff coming out with the National Grid giving it a spurious authority.

    There certainly are issues with capacity to be resolved, but the supply fuse really isn't the issue. Apart from anything else, the nature of fuses is that even if you were already taking 100% of capacity and then put the kettle on, the 10% overload would have no chance of blowing the fuse before the kettle boils and the overload goes away.

    The real issue here is that while the typical house here has at least 60A and often 100A supply, the distribution supplying an estate of houses will be based on only 2kW-3kW per house long-term average, with some allowance for short-term overload. Cables are all underground (except in rural areas) and we tend to have fewer, larger transformers than a US-style distribution, so upgrading to relieve this district-wide capacity constraint would be expensive.

    Fortunately, if you do the sums for average mileage per year, average number of cars per household etc. 2kW per household is actually just about enough for everyone to charge during the nighttime hours when demand is otherwise very low.

    But even with fairly low EV penetration there isn't enough capacity for everyone to just plug in when they get home (or to start charging at the start of the off-peak period). So we need automated demand management to spread the load. It's not clear that telling people to turn off their kettles is a useful step in that direction...
     
  3. miimura

    miimura Active Member

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    Aug 21, 2013
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    2,115
    Location:
    Los Altos, CA
    Robert @ Fully Charged also addressed this nonsense article and I had already thought about his main point - the article talks about 11kW charging and assumes that a load that size is put on a single phase service. In reality, 11kW EVSE are only used on 3-phase service which almost always has more total capacity. I'm pretty sure the most draw you will find on a UK single phase EVSE is 7.6kW (32 amps). That obviates the problem of charging on a 60 amp single phase service and boiling a kettle at the same time. Besides that, there are technological solutions that can be applied to this problem like EVSE that monitor the total draw on the service and throttle down when the service draw is nearing capacity. Somebody was intentionally throwing shade on EVs with that article. That much is clear.
     
  4. Cobos

    Cobos S60 owner since 2013

    Joined:
    Jun 22, 2007
    Messages:
    1,318
    Location:
    Oslo, Norway
    Having driven my Model S around 45000km only through home charging I'd say you don't need more than that. I've got a 16A 240V standard schuko plug as my home charger. As it only pulls 13A that's a far cry from 11kW. I'm perfectly fine with that speed.

    Cobos
     

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