Can someone check my maths, please.

I just filled up my diesel car. It took about 70 seconds to put 50 litres of diesel in the tank. Wikipedia gives diesel an energy content of 35 MJ / litre. I make it as (50 litres x 35 MJ / litre) energy added to the car in 70 seconds = 25 MJ per second = 25 MW. So that black rubber hose is carrying power at 25 MW into my car.

Interesting figure when people talk about how to charge electric cars and running cables across the pavement.

Of course the black rubber hose is piping chemical energy into the car - this is not all turned into work. But it is a sobering comparison.

mikeh, that depends on usage, surely. An EV that is used for a 10-20km round trip daily and is recharged at night or at the office incurs no 'convenience' penalty, quite the reverse.

Yes restricted usage against virtually unlimited usage.

I had an 1982 Audi 100 diesel, a single tankful would get me from Glasgow to Birmingham and back. Then just a few minutes refuelling and if I was still up for it ready to start the journey again.

Perhaps people will come to look at personal transport the way they now look at mobile phones - they need to be charged every night, and if you need complete availability or longer usage, you need to have spare charged batteries on hand.

They used to change horses every 20 miles. Perhaps there will be a roaring trade in 'battery swap-out' stations, with people paying no more regard to the battery than people do with exchangeable propane cylinders at the moment.

I am old enough for my school chemistry books to call hydrocarbons "paraffins" meaning "little affinity", which is appropriate for stuff that has spent millions of years in conditions of high temperature and pressure, without significant change.
If someone should come up with an alternative with a similar energy density I would avoid it like the plague.
Better to drive around with a few kilos of nitroglycerine under my seat!

Electric cars are a non-solution to a non-problem in any case.

"But for a daily 10-20km round trip, shouldn't you use a bicycle?" - that would be a healthy option (no need to personalize the discussion) that not everyone can manage. But what is the proportion of car trips less than 20km? Very high, I think. How many cars never do more than 50km?

I first saw solar-powered hydrocarbon synthesis on an edition of Top Gear a few years ago, I'm sure it will become cost effective someday, or perhaps hydrogen technology will render it pointless.

> How many cars never do more than 50km?

Almost 0%?

The ability to undertake an unplanned journey of >50km is essential to most. This could perhaps be overcome with more petrol driven city car clubs providing 'emergency' transport. My commute is ~10 miles through Edinburgh so an electric car _could_ be quite attractive, if they weren't so expensive with their environmentally destructive batteries.

Later on in the page they manage to get Big Oil conspiracy and impossible physics (the hallmarks of greenie goons) into the polemic:

Obviously some people don't like what we do because it threatens their business model, and we sometimes go head-to-head, but the most important thing now is getting the CO2 back down to normal levels, so we ignore our critics and push forward towards that goal with like-minded partners.

Humour aside, the idea might have some merit, I think stopping every 20 miles would be a complete PITA, but if they could extend it to say 50 miles, I think it could be a go-er.

Well maybe, but payment could be automatic like the French Liber-t télépéage tags. Charging on site might be possible at larger stations, such as major motorway services, with some being shipped around to the smaller ones. These are implementation issues, not technical. But I agree perhaps 50 miles prevents it being feasible - 100 miles?

I'm always wary of writing off solutions due to apparently showstopping implementation problems.

I was intrigued when I see discussions about wind-powered cars and smart grids and so on. I wanted some sense of how much energy I put in my car and how long it takes.

Right away it looks like the only sensible re-charging option is a network of swap-out points - where they take out a "going flat" battery and swap in a fresh fully-charged unit. All possible in under a minute. This could work like the calor gas bottles.

This is to match the hyper-mobility that the hydrocarbon-powered car makes possible. I can jump in my car with just a credit card and keep on driving to London, past London down to the channel and onto a ferry and past Paris and down to the south of France. With no planning. Then all the way back with almost no stopping.

I wasn't even considering the 'problem', I'm sure as we have said already, petrol synthesis or hydrogen tech, or something else will come along when it's economically viable long before an actual battery/cassette and all the infrastructure that goes with it ever happens.

Never mind the real-world battery life when it's -5C, snowing and dark......