back to article Uncle Sam's boffins stumble upon battery storage holy grail

According to the head of ARPA-E – the research arm of the US Department of Energy – a number of breakthroughs in battery technology have been achieved, with huge implications on the use of renewable energy and electric cars. Speaking at an ARPA-E event in Washington DC this week, director Dr Ellen Williams told an interviewer …

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  1. Doctor Syntax Silver badge

    "Which in real terms would mean cars travelling 300-500 miles on one charge for less than $10 – a fifth of the price of gasoline."

    It's not just a matter of range and cost. It's also a matter of how quickly you could get the energy into the car. Can they achieve a charge rate equivalent to a petrol pump's delivery rate and as simple to operate?

    1. Steve Knox Silver badge

      At highway speeds, 500 miles is 6-7 hours. After that much driving you should be taking at least an hour break anyway.

      Also, electric vehicles can be charged at home, which (for most of us, anyway) can't be said of petrol-powered ones.

      It's a different rhythm, certainly, but in many ways more efficient.

      1. Pompous Git Silver badge

        Also, electric vehicles can be charged at home, which (for most of us, anyway) can't be said of petrol-powered ones.

        Having run out of petrol on a number of occasions and had to thumb a ride to the nearest service station with a petrol container, I'm wondering how you get the vehicle home for a recharge. Bet the missus refuses to carry the battery for you when the nearest is a few hundred kilometres away. And for what it's worth I've "recharged" petrol vehicles at home before from the aforementioned petrol container.

        1. Fred Flintstone Gold badge

          Regenerative towing?

          I'm wondering how you get the vehicle home for a recharge

          I have seen Tesla's towed, but I'm wondering if towing wouldn't be one way to get some charge back into the batteries (slowly, of course, or it would be hard to tow). Regenerative braking without the braking, so to speak.

          1. Trevor Gale
            Joke

            Re: Regenerative towing?

            That'd give a new interpretation of 'one for the road'... (legally!)...

            Colin: "Sorry mates, can anyone help me, me battery's gone right flat?"

            Joe: "There's little blue pills you can get for that mate!"

            Colin: "No, I don't mean that, I just need to get home."

            Joe: "Ah, you don't want to keep that sort waiting!"

            Bob: "Hey, Colin, I can hook you up okay, gotta be on my way anyway. How far?"

            Colin: "It's 15 miles home but if that's too much it's only 10 to my bit on the side."

            Bob: "No problem mate, I've got some ropes in the back and 10 miles ain't too far."

            Colin: "Ta, don't get me wrong, I've already pulled but we're not into the kinky stuff".

            Bob: "Oh okay then, I can get yer home, 6 pints of the high-octane stuff okay?"

            Colin: "Yeah fine, I'll bring it round tomorrow. Tell me better half we've been playing golf ok?"

            Bob: "Yep, no worries. Ya can bring a funnel with it yes?"

            Colin: "Yeah. It's all the 'extra commuting' that's done it, never had to get a pull before though."

          2. Robert Helpmann?? Silver badge
            Headmaster

            Re: Regenerative towing?

            I have seen Tesla's towed...

            What's a "towed"? Is it related to what the French call a "crap-owed"?

        2. I. Aproveofitspendingonspecificprojects

          For what it would cost a simple bow up against the alternator could give you enough armpits to get to a station. And there is nothing to stop some boffin inventing a unicycle charger to fit a back seat. Then the spare passenger would be the back seat driver too.

          1. Vic

            For what it would cost a simple bow up against the alternator could give you enough armpits to get to a station. And there is nothing to stop some boffin inventing a unicycle charger to fit a back seat. Then the spare passenger would be the back seat driver too.

            Typical usable human energy output is somewhere around 60W.

            If the previous poster's 6KW average use figure is correct - and it feels somewhat low to me - that means you get approx 1 minute driving for every 100 minutes working (hard) at the alternator[1]. That is not viable.

            Vic.

            [1] Yes, I am assuming zero losses. i don't think it makes any difference to the core problem...

      2. uncle sjohie

        Since we don't have a driveway, and have to park in the street in front of our house, charging an electric car would mean running a cable from our house across the sidewalk to the car. And that goes for the majority of houses here in the Netherlands. I imagine that would give quite some health&safety risks, not to mention a whole new way for vandalism. And the people in those houses, constitute the bulk of car owners you need to convert to electric vehicles to make a serious environmental impact.

        1. 1Rafayal

          Put an extension (underground) to the street with a locked cover on it?

          I know it's not perfect, but if someone really wanted an electric car this would make things a lot easier.

          1. I. Aproveofitspendingonspecificprojects

            Socialism

            A dirty word for Amercan'ts but in Europe we have been using it to get things done for centuries.

          2. Whiskers

            Street charging

            >> Put an extension (underground) to the street with a locked cover on it?

            I know it's not perfect, but if someone really wanted an electric car this would make things a lot easier. <<

            That presupposes that the resident's car will always be parked in the same place. In many towns and cities one is lucky to be able to park within a few minutes' walk of home, and rarely on the same spot.

            Charging points that accept money or smart-card payments would work, but require that more or less all streets where parking is allowed have them installed. That would be a massive capital investment.

            Quite apart from the matter of actually generating the electricity to charge all those cars.

          3. Vic

            Put an extension (underground) to the street with a locked cover on it?

            Few roads round here have any ownership of parking spaces - you leave the vehicle where you can. That means I can't always park in the same street as my house, let alone alongside my putative charging point...

            Vic.

        2. Anonymous Coward
          Anonymous Coward

          @uncle sjohie

          This is one thing that so many of the advocates promote. They presume that everyone lives in a 2 car garaged suburban household.

          Take the UK Victorian streets, it's not uncommon to have to park 20m down the road, or on a completely different street altogether, forget about allocated parking, not going to happen, not enough space.

          What about tower blocks, converted factories, flats and so on?

          1. 1Rafayal

            Re: @uncle sjohie

            I guess all these people living in places that are not convenient for electric cars will need to live with the social stigma.

            At least until some SJW starts campaigning for "basic human rights"

            1. Anonymous Coward
              Anonymous Coward

              Re: @uncle sjohie (and others)

              Yes there are lots of people for whom home charging isn't the answer. It's a shame, but it's not insurmountable, shirley?

              Why does the vehicle need to be recharged at home? Why not at place of work, or shoppers car park, motorway service station, whatever? All these places can have fast chargers, quite a few of them already do here in south Birmingham, home in the 1980s to Lucas Chloride Electric Vehicles (sodium sulphur battery on Bedford CF Transit-class van) and in the 2000s to the LDV Maxus Electric (lithium ion powered Transit-class van):

              http://www.ldv.co.uk/electric_maxus.aspx

              Maybe this time round electric vehicles might actually catch on.

              1. Domquark

                Re: @uncle sjohie (and others)

                The car is a personal transportation device. The idea of which, is that you can use it whenever you want. Going backwards, and being restricted by charging times and places, and you are now removing that freedom. Given that, you might as well save yourself a fortune and get public transport instead.

                1. Anonymous Coward
                  Anonymous Coward

                  Re: @uncle sjohie (and others)

                  "being restricted by charging times and places"

                  Many people already go to the supermarket, or workplace, or retail park, anyway.

                  "save yourself a fortune and get public transport instead."

                  That'll really go down well with people that "don't want to be restricted". Especially those not on a usable public transport route, but who already drive to supermarket, workplace, retail park, etc.

                  1. Domquark

                    Re: @uncle sjohie (and others)

                    "Many people already go to the supermarket, or workplace, or retail park, anyway."

                    Yes, but how many places have charging points? And two out of three examples you have given are shopping areas - how are they going to pay for the installation? Oh, of course, they aren't - YOU, the customer are! Expensive retrofits of high current charging points will ultimately be paid for by the shopper.

                    As a point, my local Costco has electric charging points. I have NEVER seen these being used.

                    "That'll really go down well with people that "don't want to be restricted". Especially those not on a usable public transport route, but who already drive to supermarket, workplace, retail park, etc."

                    And the moral is - don't get an electric car!

                    1. itzman

                      Re: @uncle sjohie (and others)

                      My supermarket already has charging points

                    2. KeithR

                      Re: @uncle sjohie (and others)

                      "And the moral is - don't get an electric car!"

                      It's probably a big ask - but could you make your "moral" have SOME semblance of relevance to the point you were answering?

                      1. DougS Silver badge

                        Wow so many objections to electric cars

                        Because it won't work for ME. So progress should stand still until we can make it work for everyone? Please disconnect your broadband and go back to dial up, because there are people who live in rural areas for whom modern broadband isn't available. You can sign up against once the entire world has been wired for broadband, and then I'll be happy to wait for electric cars until we can solve YOUR problem of "but I park in the street down the block not in a garage".

                        Just because some people charge at home doesn't mean everyone must. In fact it probably doesn't make sense to charge at home unless you have renewable energy. i.e. solar panels on your roof with a home battery that can store the excess to recharge your car at night. Otherwise it is going to be much cheaper to recharge your car on power that's billed at lower commercial/industrial rates.

                        So how you do get those rates? Charging at a 'gas' station, or better yet automated battery swapping or best of all swapping of liquid electrolyte. Charging when parked at work. Charging in the street at home or when shopping, in designated parking spots equipped with charging that automatically bills you (the plug includes data lines so the car can ID itself to the charging station and handle those details)

                        As for the "where do we get all the power to charge all these cars, that will mean a demand for much more electricity than we can generate today". Fortunately we aren't going to replace all cars with electrics in a period of a couple years, so we don't have to worry about that. Even if we did, if ARPA-E really can do utility scale electrical storage your utility will build a few huge tanks to act as "batteries" and instantly double (or triple in hot areas of the US) their electrical generating capacity because they design based on peak load while average load is far lower. With storage they no longer have to match generating capacity to demand, so their daily output capability is greatly increased.

                        1. Anonymous Coward
                          Anonymous Coward

                          Re: Wow so many objections to electric cars

                          Nicely summarised sir. Some people might wonder if the dear departed Lewis Page had attracted a particular kind of audience round here, of the "I'm all right Jack" kind.

                          Incidentally, with reference specifically to the USA, I've seen plausible-looking papers that suggest that because the USA is significantly bigger than any weather system, you can supply the USA from wind power alone, and it's cheaper than any foreseeable approach involving storage. "All" you need to do is (a) install massively more wind turbines than you would otherwise have (b) install massive inter-regional interconnects so that windy areas can supply becalmed areas.

                          Wish I could remember where I saw it :(

                          The UK (and indeed most of Western Europe) is smaller than a weather system and therefore doesn't have this possibility.

                          1. Voyna i Mor Silver badge

                            Re: Wow so many objections to electric cars

                            ""All" you need to do is (a) install massively more wind turbines than you would otherwise have (b) install massive inter-regional interconnects"

                            The US problem (the same one we have with our railways) is the fragmentation of the electrical system, meaning that for this to happen an entirely new generation of lawyers would need to be churned out just to deal with the negotiations. Is a trans-continental supercooled underground DC line cheaper than a nuclear power plant?

                            The other problem with transcontinental windpower is the same as the one you get with, for instance, a float glass plant; you have to invest a huge amount of money before anything happens. It isn't worth building the DC line till you have enough wind turbines in North Dakota, say, but nobody will build the turbines till there is a prospect of income.

                            The Chinese, with their command economy, might do it, but capitalism does make long term large scale projects extraordinarily difficult.

                            1. Anonymous Coward
                              Anonymous Coward

                              Re: Wow so many objections to electric cars

                              "capitalism does make long term large scale projects extraordinarily difficult."

                              Capitalism arguably managed OK(ish) for quite a long while.

                              What is now in power in the US and the UK (maybe increasingly in Germany and elsewhere) isn't really capitalism as such, it's corporatism. Not really the same thing, not really interested in anything medium or long term, not really interested in anything with a benefit to wider society (cf the Quaker-founded industries in the UK, and in the US, Andrew Carnegie and his free libraries in many parts of the world, and...). If it was capitalism many global banks would be gone by now, as would the American-owned auto industry (who remembers TARP) and so on.

                              The big banks currently consider their "long term" reward schemes as based on something like three years. Right.

                              It's not going to end well without a few changes at the top.

                              "a float glass plant; you have to invest a huge amount of money before anything happens"

                              Unusual comparison, but as a long time observer of Pilkington Bros (RIP) and their successors, I see where you're coming from.

                              Pilkington had their "oh dear, what do we do when energy costs increase" moment several decades ago, not surprisingly for an industry whose main raw material is sand and whose biggest manufacturing cost is energy for heat. This paper was presented in 1992, but they'd already been working on the subject for over a decade:

                              ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=167825

                              "Energy costs and energy crises imposed upon energy intensive industries are not exclusive to the recent past. The author puts energy efficiency in the flat glass industry in to an historic perspective. The way that the industry has reacted to recent energy price rises with managerial and technical measures is briefly described"

                  2. John Brown (no body) Silver badge

                    Re: @uncle sjohie (and others)

                    "Many people already go to the supermarket, or workplace, or retail park, anyway."

                    And most have two, maybe as many as three charging points and that;s often only because they were installed for free and make good PR. I wonder what capacity cable was installed for those two or three charging points? Can they add more or will more new cables need to be layed throughout the car parking areas?

                    It's a nice idea, but I can see it being a lot more expensive than most of us expect, especially if the take up of electric cars outstrips the installation of charging points. There's two at the local council Civic Centre. Whenever I'm there, their own pool cars are on charge but the points are signed as public charging points. They don't appear to be planning for any extras "because costs and cutbacks"

                    I do hope it all works out eventually but I foresee much pain ahead with range anxiety being added to with "where the fuck is there an available charge point" anxiety.

                2. KeithR

                  Re: @uncle sjohie (and others)

                  "save yourself a fortune and get public transport instead"

                  You don't travel to work in London by train, do you?

                3. David 132 Silver badge
                  Big Brother

                  Re: @uncle sjohie (and others)

                  The car is a personal transportation device. The idea of which, is that you can use it whenever you want. Going backwards, and being restricted by charging times and places, and you are now removing that freedom.

                  But isn't that exactly what's going to happen? In the brave new world that's coming, as existing technological trends align, the masses won't have "personal transportation devices" - so wasteful, so consumerist. The future combines existing ride-sharing services with Google-style autonomous cars. If you need to go somewhere, you'll whistle up an automated travel pod from a public fleet. No worries about maintaining the car or finding somewhere to park it.

                  Also, no individuality, no chance to leave your personal possessions in the car, and someone else will have ultimate control over when, where and whether you can go anywhere.

                  Won't that be fun?

                  Only the rich and eccentrics will have personal cars; the insurance costs alone will, I'm sure, be exhorbitant ("you, a fleshy fallible meatbag, want to try driving on the road alongside the perfect, all-knowing Google AI? Ha!").

                  Bah.

              2. briesmith

                Re: @uncle sjohie (and others)

                I don't want to plan my day around where I can refuel my car. Sorry. I've got better things to do and they've got this miracle fuel which is cheap, energy dense like you wouldn't believe and in such easy supply that its price has been falling for the last few years. I think they call it petrol or gasoline or something.

                1. John Brown (no body) Silver badge

                  Re: @uncle sjohie (and others)

                  "such easy supply that its price has been falling for the last few years. I think they call it petrol or gasoline or something."

                  At least part of the reason for the recent drop in prices is the OPEC countries trying to make fracking and shale uneconomic so they can retain their stranglehold.

          2. calmeilles

            Re: @uncle sjohie

            In the UK there is funding for on-street residential charge point installations which means that in principal it's possible.

            But it means getting your local authority to do it, which means the practice might be very different.

            And nothing there will solve the bar steward parked in my spot problem even if you do manage to get one installed.

            https://www.gov.uk/government/publications/government-funding-for-residential-on-street-charging-for-plug-in-vehicles-a-guide-for-members-of-the-public

          3. Tom 13

            Re: @uncle sjohie

            Well, if you're going to make the sort of unicorn fart powered car assumptions the greens make, adding in a public plug at every car parking spot interval is small potatoes. I've even seen the first two Tesla power stations at my local grocery store just last week. I can't wait for the public to finally see through these boondoggles.

          4. Anonymous Coward
            Anonymous Coward

            Re: @uncle sjohie

            charging points in all streets.

            Put your card in, plug the car in, and leave.

            IF - and it is an IF - electric cars become reasonable, that's how it will happen

          5. Longtemps, je me suis couche de bonne heure

            Re: @uncle sjohie

            My local Sainsbury has about 15 charging points.

            Also, as soon as they start providing contactless charging bays at Sainsbury, your self-driving car will be able to go out on its own, during the day, foraging for nearby electricity whenever it gets hungry.

            And then when they achieve Artificial Intelligence as a result of the Darwinian stresses of driving in south-west London, they can socialise there, too - and the marketing people can start to exploit them by offering different types of higher status electricity - "Mine's a tall, green, skinny lattetricty..."

        3. tirk

          @uncle sjohie - no driveway

          Lots of people seem to run charge cables across the sidewalk/pavement where I live (Wimbledon, a suburb of London, where the vast majority of houses don't have a driveway). Never tripped over one yet, and heard of anyone complaining.

        4. disgruntled yank Silver badge

          Maybe not

          In my neighborhood in Washington, DC, I often see an electric car parked at the curb, charging with a line run from the house. Admittedly there is no sidewalk there, so people walk in the street. Still, I'd think the main health and safety risk, if circuit is properly wired, would be tripping over the line. There is not a great deal of vandalism of cars around here, and I have always supposed the Netherlands to be more law abiding than the US.

        5. H in The Hague Silver badge

          I'm also based in NL and the council have installed quite a number of 2-car charging posts in my area here in The Hague and they seem to be in regular use. One of my customers has charging points in their car park, as do Ikea.

      3. Chris Miller

        @Steve

        Also, electric vehicles can be charged at home, which (for most of us, anyway) can't be said of petrol-powered ones.

        I've recently bought an electric car* (plug-in hybrid). It has a 10kW battery giving a pure electric range of "up to" 30 miles (realistically, more like 20). It takes over 5 hours to recharge from empty using a 10A (2.4kW) socket at home - how long would it take to charge a car capable of a realistic 400 mile range (like most internal combustion vehicles)? It's true that I can pay (several hundred pounds, even with subsidies) to have a 16A charger installed, which would cut the time to 3½ hrs, but it hardly seems worth it for a relatively small gain.

        Public 'fast' chargers can deliver up to 60kW, but they're designed to stop charging at 80-85% 'full' (my antique A-level physics suggests to me that this is because the battery 'resistance' rises to the point where the heat generated (and energy lost) during charging becomes insupportable - can anyone confirm this idea?) But making such chargers universal would require rewiring every home in the country (and corresponding improvements to electricity generation and distribution)

        FWIW I really like the car and it's saving me a lot of money (measured 90 mpg - equivalent to 60 mpg once I include the cost of electricity) and that's for a substantial SUV. There's a Register review (of the old model) here.

        * Full disclosure: the decision was almost entirely the result of government subsidies and little to do with any desire to save the planet.

        1. John Brown (no body) Silver badge

          Re: @Steve

          "a car capable of a realistic 400 mile range (like most internal combustion vehicles)?"

          Is that pure town driving? I'd be very underwhelmed if I only got 400 miles from a tank of diesel. 700-800 is more like my normal expectations, mainly motorway driving.

      4. Anonymous Coward
        Anonymous Coward

        Also, electric vehicles can be charged at home

        That is assuming you have the electricity to do it in reasonable time as well as the money to pay for it.

        Another thing, where is all of this electricity coming from?

        1. handle

          "Another thing, where is all of this electricity coming from?"

          From renewables producing at the the time, and the same technology being used to store energy from renewables not producing at the time.

          1. Alan Brown Silver badge

            Re: "Another thing, where is all of this electricity coming from?"

            "From renewables producing at the the time,"

            If you carpeted the UK in Windmills(*) and solar PV you'd _just_ be able to match the current output of the UK power generation fleet.

            Now, factor in gas/oil heating being phased out (at least double the capacity required) and a more-electric vehicle fleet (double that again, and then some)

            "and the same technology being used to store energy from renewables not producing at the time."

            ~30% loss in energy during charge/discharge cycle translates to ~50% increase in the amount of generation capacity required.

            You're better off investing the money spent on "renewables" (which aren't green in the slightest and expensive to operate thanks to windmills eating gearboxes at a prodigious & solar PV being an environmental disaster where they're manufactured, as well as cells only having a 8 year economic lifespan) in R&D for better nuclear fleets.

            Fusion's probably 100 years away, but molten salt systems are safe enough (no pressurisation, no radioactive steam, no fire risk, can't explode and don't need water cooling) that they can be sited near populated areas to provide district heating/cooling schemes, once they're commercialised. LFTR systems would reduce the waste output of a current plant (about one olympic-size swimming pool with a layer of high level waste on the bottom per reactor, per 60-year lifespan) down to 1% of that whilst simultaneously reducing physical waste on the input by 60% (that's how much raw uranium doesn't get to see the inside of a reactor after the enrichment process) and a shedload of energy (enrichment costs are a military classified secret, even for civilian fuel supplies, but it's extremely high)

            1. Anonymous Coward
              Anonymous Coward

              Re: "Another thing, where is all of this electricity coming from?"

              "If you carpeted the UK in Windmills(*) and solar PV you'd _just_ be able to match the current output of the UK power generation fleet."

              Cite: Prof Sir David Mackay, FRS, in his excellent book of facts, numbers, and logic:

              Sustainable Energy Without The Hot Air, freely downloadable at

              http://www.withouthotair.com/ (there's an executive summary too)

              or, specifically focusing on how much ground (or sea) area does the UK need for its energy supply, there's his 18minute TedTalk at

              https://www.ted.com/talks/david_mackay_a_reality_check_on_renewables?language=en

        2. Anonymous Coward
          Anonymous Coward

          " the electricity to do it in reasonable time"

          Come back when you've looked at the numbers.

          Here are some starting assumptions: the electric car is the 2nd car, or other vehicle used for school run, shopping, or part time local commute. There's a lot of those about. Assume the charger is a plug in (3kW max).

          If you do do the numbers, you'll find that for typical round-town use, the time taken to recharge your electric car from a charger at home is very very roughly the same as the time spent driving. So an hour's drive, an hour or two's charge. The time taken to recharge from a fast charger at work or shopping centre will obviously be significantly less.

          Still see a big problem?

          1. Anonymous Coward
            Anonymous Coward

            Re: " the electricity to do it in reasonable time"

            So an hour's drive, an hour or two's charge. The time taken to recharge from a fast charger at work or shopping centre will obviously be significantly less.

            Still see a big problem?

            Yes. Forget the maths, do the physics. You're looking at charging:use ratios well below 1:1

            1. Anonymous Coward
              Anonymous Coward

              Re: " the electricity to do it in reasonable time"

              "You're looking at charging:use ratios well below 1:1"

              Never mind the physics, what the eff is that supposed to mean?

              ps

              I are physicist. What you?

              1. Anonymous Coward
                Anonymous Coward

                Re: " the electricity to do it in reasonable time"

                Never mind the physics, what the eff is that supposed to mean?

                Precisely what it says. You need to charge for 'n' hours to use it for 'm'. The ratio of n to m is much worse than 1:1. If you charge your phone for an hour can you make an hour-long call? Like fuck you can, it'll be lucky to give you 15 minutes. Same for a car.

                I are physicist. What you?

                A chartered electrical engineer.

                1. Anonymous Coward
                  Anonymous Coward

                  Re: " the electricity to do it in reasonable time"

                  Phones? Phones use lots of power when in a call, and a near negligible amount when in standby (well, pre-smartphone, anyway). Same with cars - lots of power when accelerator is hard down, much much less when travelling normally, when there's just air resistance and rolling resistance to overcome, and maybe accessories to operate. Also, electric vehicles have regenerative braking which recovers some kinetic energy when braking; no equivalent on phones.

                  In an earlier post you can see my worked example, with facts, numbers, and logic, based on Mackay-derived figures. I don't intend to repeat it here, but for simplicity I'll come at it from another angle.

                  For the sake of simplicity I'm going to ignore charging losses. You may wish to do otherwise and adjust the answers by a few percent.

                  A commuter-run or school-run vehicle does not use anything like maximum power for any significant proportion of the journey. Its average power use will be much less (especially given regenerative braking) than the battery output power or motor output power. Increased use of the right foot will cause an increase in average power consumption. I'm assuming lots of slow or stationary traffic around town. Sustained motorway-class speeds will also change the numbers.

                  So, if you have a 3kW charger and your power consumption while driving is *on average* 6kW (after accounting for regenerative braking), then if you drive that way for one hour it takes two hours to recharge.

                  Obviously a fast charger will be quicker, depending on the available power.

                  What, other than the explicit disregard of charging losses, is wrong with that?

                  1. Anonymous Coward
                    Anonymous Coward

                    Re: " the electricity to do it in reasonable time"

                    What, other than the explicit disregard of charging losses, is wrong with that?

                    Physics, or perhaps electrochemistry.

                    Current battery technology doesn't permit charging at anything lke the same rate as discharge, for reasonable battery life you're looking at charge rates of C/5 with charge times of 2-6x discharge. Take a battery rated at 3KW discharge and fill it at 6KW and those charging losses you're so blithely disregarding may reassert themselves in a fairly spectacular fashion. Your battery won't be good for more than a small number of cycles if (ab)used that way.

                    Now, maybe some novel new battery technology will change that, or supercapacitors may become energy-dense enough, but for today's battery technology it's a non-starter.

                2. Col_Panek

                  Re: " the electricity to do it in reasonable time"

                  The difference is that you don't normally drive your car all day like you run your phone.

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