OT: Electric cars

[SteveW]

Yes and yes.

[RJH]

That, and the reduced emissions.

I think it makes perfect sense for most - were it not for the cost of buying it in the first place.

[Bob Martin]

That's in very poor taste, considering Hannah is recovering from breast cancer.

[Chris J Dixon]

The primary action is required on the trains themselves, and can be far from trivial.

It is a constantly changing subject; as technology advances, so does understanding of the performance of a number of different signalling systems. It has often been the case that very tight requirements for new rolling stock would not be met by the existing trains with which it will be running.

There was a particular case on a job I was involved with, where the new vehicles had to be fitted with a sensitive monitor which would shut down the train upon detecting any exceedence of defined interference limits.

It was designed, built and tested OK, then, in real world operation, it would occasionally be triggered by interference created by an older train running past it. :-(

Chris

[Jim gm4dhj ...]

1966/67

[charles]

At some point in the late '80s. I took a phone call fromBREL in Derby who wated to kow the field strngth of the Droitwich LF tranmsitter in Derby. I looked it up and told them. I was asked if I was certain and confirmed the figure. "Oh dear, we are only measuring on tenth of that." They were pronbably measuring interference levels rather low, too.

[alan_m]

For electronic goods the advances have been in the geometry of the ICs rather than advances in battery technology. Smaller geometries have resulted in much lower power. When I first joined the electrics industry it it was 5V logic and 10s to

100s of transistors in a single IC. When I left work it was 1.8V interfaces and internal 0.7V logic in ICs of many millions of cells/gates/transistors.

[alan_m]

But how long are these right tariffs likely to remain? In the past weeks we have already had a period of 4 days where the generation of off peak electricity has probably cost a lot because wind/solar was turned off. When the take-up of EVs becomes greater and charging overnight competes with the demand of the ASHP for central heating is there going to be any cheap electricity generation, especially in the colder months

[alan_m]

It may depend on where and how you drive. I do note that some of the manufactures are now quoting two ranges - one for speeds, say, less than

40mph and another for normal motorway type driving. I cannot find it now, but 12+ months back I found a manufactures web site where the headline range (miles per full change) dropped by 50% if you wanted to do the journey at a legal motorway speed in colder weather.

This is possibly not a consideration if 99% of your usage is the urban supermarket run or joining the traffic jam on your normal short commute to work.

Is your calculation based on the manufacturers optimistic miles per full charge figures?

[NY]

Yes I agree that PHEV (or DHEV if diesel wasn't a dirty word) are the best of both worlds: providing they have large-capacity batteries they can run on electricity in a town centre where pollution is more of a problem and where inefficient stop-start driving is more common, and then run on petrol (also charging the battery) out of town on the motorways and faster A roads, and can be refuelled quickly and easily.

[The Natural Philosopher]

No. Jethro, that is absolutely *not* the problem.

Although given the greenspin everywhere in the media you might think so. The problem is that no viable storage at the level required even exists in theory, let alone at sane cost.

Government priorities are, it seems:

1/. To get re-elected, by constant opinion polls to indicate which lies will find most favour with the public 2/. To feather ones nest to allow for the serial divorces and steamy sex sessions one will inevitably indulge in 3/. To feather ones family and cronies nests 4/....while maintaining an illusion that 'something is being done' to allay public concerns over the latest hobgoblins

[The Natural Philosopher]

SR is/was always 630V DC on the third rail. I forgot wt was decided about the underground, but it was different. I remember my childhood bedroom faced a SR line about half a mile away and at this time of year I would get woken at sparrow fart by mighty flashes as they ran a dummy service to clear ice off the third rail.

[The Natural Philosopher]

No, that is not such an issue.

The issues are simply ones of where the lithium is coming from, where the electricity is coming from, and where the charging stations are going to go and how much this will all cost as against e.g. manufacturing synthetic fuel from nuclear power

[Chris J Dixon]

Way back in the 70s on the Brush/GEC class 314 prototype (converted from a 2-car PEP), there was much interest in possible interference with signalling and so forth, but the instrumentation available was pretty crude by today's standards.

We did have a storage oscilloscope that used nearly a kilowatt of power, most of which it blew out as hot air, for which we were very thankful during cold night testing.

We all saw "interesting" traces when the VCB switched, but there was great doubt whether these were real, or an artifact of the instrumentation.

I was doing test runs on LTS and around Glasgow. Practically every night test run that I was on involved both the thyristor unit and a conventional tapchanger/ rectifier unit.

The general feeling from the railways at the time seemed to be along the lines of "Gosh, what a lot of harmonics (1) the existing stock are generating, we better put the results at the back of a drawer and let the new stuff run.

(1) We had an oscilloscope displaying the 25 kV supply waveform, and at times it was so distorted that it had a number of extra zero crossings per cycle,

Chris

[The Natural Philosopher]

Well so are Lucy Worsley's.

But I like Hannah. The nose is a bit prominent as I recall

[The Natural Philosopher]

And as I keep repeating, application of electrochemical laws shows that they never will be.

There is a little more to be squeezed out, but not very much.

[The Natural Philosopher]

Apparently EV still marginally cheaper as its untaxed

If you take an 80kWh battery as being able to do 200 miles, and £40 quid of diesel to do similar, 80 x 0.34 is around £27 .

Petrol is closer. Especially that ethanol loaded shit.

[The Natural Philosopher]

Make that 2/3rds and I agree.

[The Natural Philosopher]

Of course not.

Home car charging could easily make up the bulk of nighttime demand, smoothing out the demand curves and making solar power even less useful.

Ideal for nuclear power stations. Wind? Not so much

[The Natural Philosopher]

Well of course there was.

Back in around 2000 I could barely fly an electric model plane for 5 minuutes, but then NiMh, and then lithium Ion took that up to over half an hour with massive performance. It is now still at that level.

It hasn't got any better in over 15 years. The batteries are cheaper and last longer and don't blow up quite as much, but the capacity to weight is slightly WORSE than it was, due to them being safer.