Yes, but drag increases as the square of speed. You can’t assume that if it takes X energy to do the journey at 15mph then it takes 4X to do it at 60mph.
@aart I’ve no source, it’s a general observation. Since you’re making the claim of enormous and rapid development in the near future, I suggest the burden of evidence is on you. I don’t accept puff pieces on websites no-one’s ever heard of as evidence.
Yes, if it takes X amount of energy to overcome aero drag over a certain distance at 15 mph it takes 16 times that amount of energy at 60 mph (roughly, as a rule of thumb).
Power to overcome parasitic drag increases as the cube of speed, therefore energy used to overcome that drag over a given distance goes as the square of speed because the time involved is proportionately shorter.
Rolling resistance is constant with speed, so energy used is the (constant) rolling resistance times the distance.
The energy used to cover a certain distance at a certain speed is the combination of the two. In something like 1985 I took my 42 mpg motorcycle of that time to the racetrack and was surprised that it got 15 mpg 
Yes, I realise that. It’s apparent on a bicycle in a way that isn’t on a car. Usually the point where rolling resistance equals air resistance is about 12mph. 15mph on the flat is easy and you can keep it up indefinitely, but 30mph is utterly exhausting.
In a velomobile aerodynamic drag is considerably less than on a regular bicycle so you can go faster for the same effort. Mine is slow, but something like the Snoek will do about 35 mph on the flat, with a power input of 250W. Lithium batteries give about 150 Watt hours per kg, so if you were to carry a perfectly reasonable 40kg of batteries and pedal at the same time (150-250 watts), you could go quite far at a speed that would be less than that of a car, but still reasonably respectable.
The issues are that the world is not flat (Wales in particular – which is where I live though not on the route) and legally the power assist is limited to 15.5mph and 250 W so in practice you would end up crawling up the hills and descending them at high speed.
Due to the square/cube laws, this usually means that one’s average speed is rather slower than it would be on the flat. There’s a hill nearby that I ascend at about 4mph for 10 minutes and descend at 40mph for 1 minute. This takes far longer (11 minutes) than if I were to ride at a steady 20 (2 minutes); essentially my average speed is strongly dependent on my hill-climbing speed. However if you lifted the restriction on speed for electric bikes ascending hills, the average speed would increase a huge amount but the battery usage would not increase that much because most of the energy on a hill climb goes into overcoming gravity rather than air resistance.
When I was toying with the idea, the question I was asking wasn’t ‘how far is it’ but ‘how much climbing’ would the trip have?
The progress in battery technology over the last few years can clearly be seen in Formula E.
A Formula E race covers a distance of 80 -90km on a charge. The cars travel at speeds around 174 miles per hour. A race lasts 45min plus 1 lap. The races are all on street circuits.
In formula 1 (ICE engines) have a set distance of 305 km except for the Monaco street circuit which is only 260km.
Any longer and the formula 1 cars would have to refuel. Not long ago formula 1 cars were refuelling during the race.
The big difference is that up to a year or maybe 2 ago to achieve the 80 -90km in a Formula E race it was mandatory to have a change of batteries ( read car) at the half way stage. That is no longer necessary because of improvements in battery technology over the last few years.
Formula E does not need tyre changes during the race because of the type of tyre and longevity of it as opposed to formula 1 which can need 2 or 3 changes during a race.
The amount a team can spend on a formula E car is limited to €250000 whereas a formula 1 team spends in the millions on a car.
The minimum weight of a Gen2 formula E car is set at 903kg including driver of which 385kg is the batteries.
Gen1 formula E cars were capped at 923kg with an extra 65kg of batteries.
A formula 1 car must weigh a minimum of 798kg with the engine weighing at least 150kg. The gearbox also weighs in at 40kg.
So not internet fluff here these are actual figures which IMO demonstrate that EV technology including the battery technology is improving and not just plateauing.
Well. After following this discussion for a while, you get the impression that there are two different realities. Some people live in a reality where EVs are a practical impossibility. Other people live in a reality where they are very happily driving their EV’s every day.
Now, I don’t really believe that there can be different realities, so one of these two groups must be wrong.
It depends on circumstances.
See my post about parking options. Probably most of the population cannot home charge.
And “travelling salesman” scenario is infeasible if too many in one street.
Multiple facets.
Yes, there’s been a lot of development in battery technology in the last decade or so. I simply contend that it has plateaued and without a fundamentally new technology we are not likely to see the 5x – 10x improvements necessary to bring the energy density into line with liquid fossil fuel.
Note also that the current state of the art depends on the not-exactly-widespread and thoroughly unsustainable lithium. There’s a lot of it, but it’s in inconvenient places. Difficult energy geopolitics seem inevitable.
EVs do of course ‘work’ with the present technology. But they work for the likes of us, with our well-above-average incomes and big houses with driveways and two-car garages, with our relaxed and adaptable lifestyles. But for the masses in apartment blocks?
It doesn’t work where you need to haul heavy weights up hills or into the air – the energy density of the supply is just not sufficient. Formula E is probably a poor advert for the tech, given the cars (by design) carry almost nothing and carry it to no practical purpose.
Couldn’t you say the same for formula 1 or going into space? Yet much of what we take for granted today has evolved from the research into these areas.
I didn’t say it wasn’t worth doing for research (or sporting) purposes.
I said it wasn’t a good example of battery-powered vehicles carrying heavy loads over long distances involving uphill gradients.
Horses for courses..The early TGV in France were gas turbines but following the oil crisis of 1973 gas turbines were deemed uneconomic and the project turned to electric lines powered by nuclear power stations.
What I have been trying to say is that there are and always will be hurdles to overcome and every solution to every problem brings out the naysayers, the deniers, and the opponents of anything different, many of whom would rather persuade those who do things that they should concentrate their energies elsewhere.
The problem with the supply of energy and many believe when it comes to the health of the planet and the people on it, there is no status quo. We do not have the opportunity to do nothing and wait.
I do not have an EV. Not because I am against them and not because I don’t believe they are the right solution to some of our problems going forward. They just are not right for me at this time. But they could be in a few months.
