How Wireless EV Charging Works

[JohnW2]

think one thing we can rely on is that if it’s one insurer taking a punt, then all the rest will watch closely to see how it works out for them.

Indeed. That's what I said - as far as I am aware, only one insurer has so far done it, maybe much too quickly to be 'wise' - so, as we have both said, the other insurers will presumably be watching very carefully to see if that move was a mistake that they would want to avoid repeating.

 

[ericmark]

The problem is the knee jerk reaction, some one has an accident in a 40 MPH limit, so reduce speed limit to 30 MPH, but ignore the person involved in the accident was actually doing 60 MPH, so reducing the speed limits has no real effect.

If every bend has a sign dangerous bend, you start to ignore them, if only ones which are dangerous have signs, people start to pay attention to them.

I have started to get use to the 20 MPH, I can accelerate to 20 MPH in a very short time, so need to leave less gap before pulling out, which is all well and good if the other driver is doing 20 MPH, but heard a few squeals of brakes after I have reached 20 MPH but the car behind is still closing the gap, so either my speedo is out, or his speedo is out.

As to insurance, if they can raise the premium when people are caught speeding, and with 20 MPH speed limits more are caught speeding, then they can reduce the base level premium for those who never get caught.

However what has this got to do with wireless charging. There is no reason not to have a hybrid, a vehicle which can charge batteries while travelling on some roads, and use the batteries on others we are seeing it with railroads, so why not with other roads the question is how to get the power into non railed vehicles, we are seeing the return of the trolley bus but to fit pick up poles on cars to reach as high as those on the trolley bus is not really an option. And there is also the problem how would you charge for the energy?

If we can reduce peoples reliance on cars, then we can have trains and buses which people will actually use, and so make them pay for themselves, but I live in what is considered as a town, we have a garage which also sells some general store items, a post office which also sells some general store item, one general store bit like the one in open all house, a butchers, two hair dressers, and three pubs, and two churches, a railway station which only runs trains in the summer, and a bus service where first bus is far too late for people to go to work on, and last bus far to early for people to return from work on, and it takes longer than the train which has a 16 MPH speed limit so the 8 miles to a town with some supermarkets takes 50 minutes. I am actually faster on my e-bike, but the winding roads and hills means the e-bike is not really safe, specially in summer with tourists.

There is no foot path never mind cycle track to the town with supermarkets, the two supermarket towns Welshpool and Newtown are connected with a foot path and cycle track away from road traffic (canal tow path) but here I am forced to have a car, even if only used once a week.

But the mileage run up with the car is 75% if not more, when I go on holiday, so need a car which can be refuelled fast and without any special things on my phone, either use cash or standard bank card. I have watched people at the local railway messing around trying to pay for electric using a mobile phone, to me that is a non starter.

 

[morqthana]

The problem is the knee jerk reaction, some one has an accident in a 40 MPH limit, so reduce speed limit to 30 MPH, but ignore the person involved in the accident was actually doing 60 MPH, so reducing the speed limits has no real effect.

With enforcement it does, because the penalty for doing 60 in a 30 limit is greater than for 60 in a 40. And for 60 in a 20 I think the chance of the real effect of the driver being taken off the road is pretty high.

I have started to get use to the 20 MPH,

Good. So no more having to stare at the speedo when driving and being less safe...

I can accelerate to 20 MPH in a very short time, so need to leave less gap before pulling out, which is all well and good if the other driver is doing 20 MPH, but heard a few squeals of brakes after I have reached 20 MPH but the car behind is still closing the gap, so either my speedo is out, or his speedo is out.

When you pull out onto a 40 or 50 road, do you just assume that an approaching car is only doing 40 or 50?

However what has this got to do with wireless charging.

Nothing.

to fit pick up poles on cars to reach as high as those on the trolley bus is not really an option. And there is also the problem how would you charge for the energy?

Were we to solve the connection problem (e.g. wireless), cars could easily be fitted with meters. Actually, the simplest approach might be for software in the charge management system in the car to log it.

 

[morqthana]

Don't you realise that it was not really a joke but, rather, a reminder of the reality - that the argument goes all the way down to zero - so that, no matter what the speed limit (even if already 20 mph, or even 10 mph), the number of collisions would reduce if the limit was reduced even further?

But in what way is it a sensible argument against reducing to speed limits to 20mph?

Because all it seems to say, basically, is

"Why reduce speed limits to 20? If you want to do it for road safety reasons then why not reduce it to zero?"

It really is an appeal to ridicule - if you present the logical end point of reducing speed limits on safety grounds as reducing them to zero, which is ridiculous, you're trying to portray any reduction as ridiculous.

 

[morqthana]

Indeed. "Diminishing returns" is really a variant on what I have said - that the less the 'problem', the less scope there is for any 'solution' to reduce that problem. Furthermore, in terms of the physics, even a fairly large decrease in a 'low' speed limit has much more effect on kinetic energy (hence capacity to injure/kill) than does a fairly small decrease in a higher speed limit.

I wonder if you meant to write "even a fairly large decrease in a 'low' speed limit has much less effect on kinetic energy (hence capacity to injure/kill) than does a fairly small decrease in a higher speed limit"?

The reality is, of course, that reductions are relative, so the percentage reduction in kinetic energy between 30 and 20 is over twice that between 70 and 60.

i.e. much more meaningful.

Plus the main safety focus for 20mph limits is pedestrians and cyclists, and the increased likelihood of them surviving an impact of 20 vs 30 is considerably greater than the comparison between being struck at 60 instead of 70.

The sensible amongst us have agreed that it all comes down to a 'compromise' (and that that compromise requires a decision about the "acceptable number of deaths/injuries").

A compromise is a position between two competing/incompatible "extremes", e.g. a union wants a 10% pay rise, the employers want a 0% one, and they end up compromising on 5%.

So what is the competing/incompatible position to the reduced speed limit one which requires both ends to meet at a compromise?

However, there will always be some who say "one death is one death too many" -and that is no sort of 'compromise'.

I'm not convinced that as a policy goal we should design systems so that they kill people. And even if "one death" is unavoidable, frankly I find it monstrous to say that it isn't too many.

Imagine someone tasked with a complete ground-up design for a town, which would include transportation systems.

If they asked "How many people is my transportation system allowed to kill?", what sort of answer do you think they would get?

Would it be conceptually different to "How many people is my water supply allowed to kill?"? Or "How many people is my electricity generation and supply system allowed to kill?". Or "How many people are my restaurants allowed to kill?"

I don't know if I mis-heard but just a couple of days ago I think I heard on TV that one of the Scandinavian countries (Sweden?) has declared a policy of 'eliminating' road deaths - which, if true, is surely just plain silly?

Read this, and see if you still feel that way.

More than a million people die on roads every year. Meet the man determined to prevent them

Almost 30 years ago, a revolutionary idea changed the way Europe regarded road collisions. It has probably saved countless lives but it's yet to be fully accepted by politicians.

www.bbc.co.uk

I also find it a little odd that this move to reduce 30 mph limits to 20 mph does not seem optimal in terms of the 'big picture'. Only about 30% of road deaths are on 30 mph roads and, probably more to the point (as above) a reduction from 30 to 20 mph will reduce kinetic energy by less than would, say, reduction from 70 mp[h to 66 mph.

That observation seems at odds with all that you have said about compromises, and acceptable casualty figures, and diminishing returns.

How many of those 30% of deaths are susceptible to being avoided by a reduction from 30 to 20?

How many of the other 70% are susceptible to being avoided by a reduction from 70 to 66?

Which speed limit change would produce more meaningful reductions in deaths?

a reduction from 30 to 20 mph will reduce kinetic energy by less than would, say, reduction from 70 mp[h to 66 mph.

Barely less. If we invent a unit for KE called the 'oof', such that KE is equal to v², 30 to 20 reduces it by 500 oofs, 70 to 66 by 544 oofs.

But in what might be regarded as an inverse of the "pill problem", 30 to 20 sees a reduction on oofs of 55.6%, 70 to 66 11.1%

 

[morqthana]

True, but I wasn't talking about just one 'small area'. Rather, I was talking about many (mostly small) villages, observed over a period of a few decades.

In some senses you highlight the issue I was discussing. Nation-wide, the speed limit reduction might have a measurable effect,

Then why not do it nation-wide?

but from the POV of those in one of these small communities, where one road death might, on average, occur once every few decades, the need for measures to reduce that tiny incidence even further might be regarded as questionable.

So is the need for the current measures also questionable?

In any event, as I have just written, I wonder a little why there is this concentration on (reducing) 30 mph limits, when there are more deaths on roads with higher limits and, probably more to the point, much more scope for reducing kinetic energy (with modest reductions in speed limits) where the speed limit is higher.

Because the benefits are much more meaningful at the low end. A pedestrian struck at 30mph has a 20% chance of being killed, at 20mph it's 2.5%.

I'm as sure as I can be that it's 100% for both 70mph and 60mph.

And as I've said before, the 20mph limit is not just about accidents and casualties. No matter how insistent you are on ignoring the other factors, they are, and will remain, real.

 

[morqthana]

Your tongue in probably firmly in your cheek but, as you say, that would actually be a totally logical approach.

If I said it wasn't t-i-c, how realistic an approach do you think it would be?

Indeed, once these changes to 20 mph limits has become very widespread, then maybe there would then be a stronger argument for trying the 'empirical' approach you suggest, by increasing those (lowered) limits until one got close to the 'acceptable number of casualties"

Even if you could get any traction at all for the basic idea that we could afford to increase speed limits because it would be OK for more people to become casualties of RTAs, you'd surely have to have a reason why you wanted them increased.

Even if you thought that an increase in casualties was acceptable I'm assuming that your reason wouldn't be that you desired it, so what would it be?

 

[JohnW2]

But in what way is it a sensible argument against reducing to speed limits to 20mph?

It's not, and I have never claimed that it is.

Because all it seems to say, basically, is "Why reduce speed limits to 20? If you want to do it for road safety reasons then why not reduce it to zero?"

I've never suggested any such thing - any more that I have suggested that rules/regulations should reduce the risk of electric shock to zero. I am merely reminding people that there IS a continuum all the way down to zero risk - which, combined with the other side of the 'balance', means that a 'compromise' has to be struck.

 

[JohnW2]

Then why not do it nation-wide?

That's quite probably what will happen. However, it is not necessarily sensible to impose wide-ranging restrictions (in anything) in order to achieve something primarily in a subset of situations. One could forget about requiring different IP ratings in different situiations but, instead, require everything to be IP68.

So is the need for the current measures also questionable?

In some locations, yes (in my opinion). Note that I am saying that it is 'questionable', not that I am 'sure' that it should not be done.

Because the benefits are much more meaningful at the low end. A pedestrian struck at 30mph has a 20% chance of being killed, at 20mph it's 2.5%. ... I'm as sure as I can be that it's 100% for both 70mph and 60mph.

That's probably true of impacts with pedestrians, but such events are presumably very rare on 70 mph roads. In terms of vehicle occupants, I wouldn't be so sure about that. It's essentially deceleration that kills, not impact speed, and a combination of vehicle design (crumple zones etc.) and air bags has made a very big difference to that. Albeit with greater 'safety measures', look at what Formula 1 drives walk away from these days. I've seen a good few people who have survived very high (impact) speed collisions in modern vehicles.

And as I've said before, the 20mph limit is not just about accidents and casualties. No matter how insistent you are on ignoring the other factors, they are, and will remain, real.

I have acknowledged that there are other considerations. I am not 'ignoring' them but, as I've said, have been only discussing 'accidents and casualties' - not the least because the other issues are far more difficult to quantify (hence 'research')

 

[JohnW2]

If I said it wasn't t-i-c, how realistic an approach do you think it would be?

As I said, it would seemingly be a logical approach, regardless of whether opr not your comment was 't-i-c'.

Even if you could get any traction at all for the basic idea that we could afford to increase speed limits because it would be OK for more people to become casualties of RTAs, you'd surely have to have a reason why you wanted them increased.

Well, in the most general of senses, I think one has to question any sort of restrictions, in any field/situation, which may achieve little or nothing.

For example, if you really are "as sure as you can be" that 60 mph impacts are as likely to be 100% fatal as are 60 mph ones, then what are the 70 mph limits achieving? One answer is clearly that the probability of a collision increases with increasing speed (not the least because of reaction times etc.) but you seem to believe that, once a collision has occurred, a 70 mph limit does not alter the outcome?