New battery charging technology to make OHLE redundant?

[HSTEd]

It's looking increasingly likely GW electrification may be redundant as before it's even rolled out...

http://www.techworld.com/personal-t...cars-that-charge-in-minutes-possible-3651281/

Unless you are proposing a 400kV circuit be constructed to Paddington across Central London and absolutely massive transformers and other equipment be placed in and around the station - this is rather irrelevant.

Faster charging means much much higher charging powers.


Additionally, is GOBLIN going to be hit by the insane new clearance limitations or did it slip under the wire for that?

 

[GRALISTAIR]

It's looking increasingly likely GW electrification may be redundant as before it's even rolled out...

http://www.techworld.com/personal-t...cars-that-charge-in-minutes-possible-3651281/

No - does not solve capacity problems

 

[superkev]

It's looking increasingly likely GW electrification may be redundant as before it's even rolled out...

http://www.techworld.com/personal-t...cars-that-charge-in-minutes-possible-3651281/

Not often mentioned with regard to electric vehicle's is where all the juice is going to come from particularly with local distribution systems.
Shortening the charging time means more current required. London's latest electrics needed a new 11kv substation for just 51 buses.
And, what happenens when all those 28kw Nissan leaf owners get home and plug in.
Same with trains. Short charging times requires huge amount of uneconomic short duration power..
K
K

 

[edwin_m]

Not often mentioned with regard to electric vehicle's is where all the juice is going to come from particularly with local distribution systems.
Shortening the charging time means more current required. London's latest electrics needed a new 11kv substation for just 51 buses.
And, what happenens when all those 28kw Nissan leaf owners get home and plug in.
Same with trains. Short charging times requires huge amount of uneconomic short duration power..
K
K

You'd hope that the charging of many vehicles evens out the average consumption, just as it does with trains motoring and braking at present. However the power that can be delivered in one place is limited, for 25kV by the heat in the overhead wire where the pantograph touches (especially if not moving) and for 750V by nearly every part of the system.

But there are several reasons why a battery system is going to use more energy than an OLE system doing the same job, ranging from the inherent inefficiency of a battery to the extra weight to be carried. So, however fast the charging time, batteries in trains are only likely to be economical for relatively lightly used branches. And as I've pointed out elsewhere the UK has a big challenge expanding generating and distribution capacity to accommodate all those electric cars while also reducing the carbon footprint, so we don't really want to add to that unnecessarily by increasing the power consumption of the railway.

 

[NotATrainspott]

Not often mentioned with regard to electric vehicle's is where all the juice is going to come from particularly with local distribution systems.
Shortening the charging time means more current required. London's latest electrics needed a new 11kv substation for just 51 buses.
And, what happenens when all those 28kw Nissan leaf owners get home and plug in.
Same with trains. Short charging times requires huge amount of uneconomic short duration power..
K
K

We're likely to see even faster charging in future. There are plans to build out a network of chargers capable of delivering 350kW, which should be fast enough to recharge a bus in the dwell time at a bus station.

Slowing down charging doesn't necessarily reduce the requirement on the local grid. Charging a bus at 350kW will obviously take seven times the amount of power as a 50kW charge would, but it would then be charged seven times faster. To charge the same number of vehicles in the same amount of time, you then need to be charging seven times as many of them at the same time, so your total power requirement doesn't decrease. Meanwhile, charging faster is far more economic, as it allows faster and more efficient turnarounds and means that less space is needed for vehicles to sit around doing nothing when charging.

With smart metering we're going to see Economy 7 on steroids, especially when most vehicles will be owned by major companies like Uber and they'll be driving and charging themselves autonomously. The company's algorithms will mean that vehicles will preferentially go and charge whenever energy prices are low and the saving is enough to justify the slightly later response time for a pickup. When prices rise, cars will go out into the world and use their battery reserves. If prices rose a lot, it's possible that cars would then go and plug themselves in to provide electricity back into the grid. The total installed storage capacity in all of these vehicles will be absolutely enormous. On top of this you'll have all the static storage capacity installed across the grid to handle the supply from renewables.

 

[HSTEd]

Slowing down charging doesn't necessarily reduce the requirement on the local grid. Charging a bus at 350kW will obviously take seven times the amount of power as a 50kW charge would, but it would then be charged seven times faster. To charge the same number of vehicles in the same amount of time, you then need to be charging seven times as many of them at the same time, so your total power requirement doesn't decrease. Meanwhile, charging faster is far more economic, as it allows faster and more efficient turnarounds and means that less space is needed for vehicles to sit around doing nothing when charging.

That all assumes that your charging periods are still long relative to the rate of recharging. Which might be true for cars and such but it is not entirely clear that is true at a single location for the railway and the like.

If your peak charging demand is 100MWe at Paddington station, you have to be able to provide 100MWe even though the average load is a small fraction of that, even if the entire national rail charging load is near constant.
You don't get diversity until very large scales.

Charging a ten car train for a 300km journey would require something like 6,600kWh be delivered. To deliver that in ten minutes (preventing the timetable from collapsing due to late arrivals will result in charging periods much shorter than layovers now) would require something like 40MWe, before inefficiencies are taken into account.
Whilst it would be normal to have only a small fraction of platforms charging at once, it is entirely possible that whilst recovering from disruption with a procession of trains arriving that every platform could be drawing charging load at once. Which means you could be looking at over 500MWe peak demand.

You would struggle to provide that kind of charging load without 50kV or even 100kV supplies to the trains. Even 40MWe at 25kV is going to come out over 1600A after efficiencies are taken into account.

With smart metering we're going to see Economy 7 on steroids, especially when most vehicles will be owned by major companies like Uber and they'll be driving and charging themselves autonomously. The company's algorithms will mean that vehicles will preferentially go and charge whenever energy prices are low and the saving is enough to justify the slightly later response time for a pickup. When prices rise, cars will go out into the world and use their battery reserves. If prices rose a lot, it's possible that cars would then go and plug themselves in to provide electricity back into the grid. The total installed storage capacity in all of these vehicles will be absolutely enormous. On top of this you'll have all the static storage capacity installed across the grid to handle the supply from renewables.

Forgive me if I don't find this future with enormously varying electricity prices particularily appealing.
The poor spending the winter praying for windy weather so that they can afford heat and light, or even to be able to cook dinner, sounds rather grim to me.
Minute to minute smart metering, and thus the renewables that require it, are possibly the greatest threat to the living standards of less fortunate members of the society in decades.

 

[highdyke]

I'm not entirely sure why you want to provide charging at Paddington, rather than say at locations near major parts of the grid (Old Oak, Hayes, Didcot, Royal Wootton Basset etc) using modest lengths of OHL or depots via an intermediate storage facility. (Assuming you can scale up enough for rail).

But anyway, that's not what I was getting at. Surely developments in super capacitors, with their potentially greater storage, allows for significant gaps in OHL reducing cost (say problem areas like Dawlish, or under a series of difficult to raise bridges) as well as the ability provide power should the OHL fail.

There's also the possibility in the near future that rail could lose its natural environmental advantages, should EVs take off with a series of fast charging points. Potentially the car could be the greener option over the competing old fashioned diesel train, especially on many lines where the load factor is poor.

 

[HSTEd]

I'm not entirely sure why you want to provide charging at Paddington, rather than say at locations near major parts of the grid (Old Oak, Hayes, Didcot, Royal Wootton Basset etc) using modest lengths of OHL or depots via an intermediate storage facility. (Assuming you can scale up enough for rail).

You would need many miles of OHL even at maximum permitted draw to allow the train to recharge on the move without having to slow down enough to collapse the timetable.

The OHL would also have to be rebuild to far higher specifications than currently to cope with a long succesion of trains running their VCBs at maximum rating for the trip out to Heathrow Junction for example.

But anyway, that's not what I was getting at. Surely developments in super capacitors, with their potentially greater storage, allows for significant gaps in OHL reducing cost (say problem areas like Dawlish, or under a series of difficult to raise bridges) as well as the ability provide power should the OHL fail.

The problems associated with over-extended pans tripping ADDs and the like mean that regular gaps in the wire are extremely problematic operationally.
In most cases it would be cheaper to keep the wire continuous and pay for the bridge raisings in the long term.

Now supercaps could help with bi-modes, but discontinuous electrification is effectively a false economy.

There's also the possibility in the near future that rail could lose its natural environmental advantages, should EVs take off with a series of fast charging points.

Cars are slow and always will be. It is inherent in the transport mode.

 

[33Hz]

Not often mentioned with regard to electric vehicle's is where all the juice is going to come from particularly with local distribution systems.

And, what happenens when all those 28kw Nissan leaf owners get home and plug in.
K

They charge overnight when grid demand is 20+ GW lower.

Do the maths and you'll find there is enough spare capacity in the grid for all cars to go electric.

 

[HSTEd]

They charge overnight when grid demand is 20+ GW lower.

Do the maths and you'll find there is enough spare capacity in the grid for all cars to go electric.

Local distribution systems in residential areas would collapse if everyone tried to charge a car at once, even if the total national grid peak demand didn't change.

You would need to drastically increase the number of 11kV/LV substations, add massive numbers of 11kV Feeders, and probably rebuild the 33kV distribution network and maybe even the 132kV sub-transmission system.

Grid demand would shift miles from the centre of a city to its suburbs at night and shift back during the day.

 

[superkev]

I said the local distribution which is designed with a large diversity. For example a typical house fuse is 80amp ~ 20kw but the local distribution is not rated anything like that so if say several Nissan leafs with 28kw batteries where plugged on at the same time the sub station would overload.
I read a company in London wanted to introduce a fleet of electric vans but couldn't because of this very problem. The 51 electric buses just introduced needed a new 11kv feeder and substation making the economics very shaky.
This is true of any future trains where all the energy consumed during the days running of all the trains has to be put back in a short time requiring a lot of infastructure either oversized feeders or even more batteries.
K
K

 

[NotATrainspott]

That all assumes that your charging periods are still long relative to the rate of recharging. Which might be true for cars and such but it is not entirely clear that is true at a single location for the railway and the like.

If your peak charging demand is 100MWe at Paddington station, you have to be able to provide 100MWe even though the average load is a small fraction of that, even if the entire national rail charging load is near constant.
You don't get diversity until very large scales.

Charging a ten car train for a 300km journey would require something like 6,600kWh be delivered. To deliver that in ten minutes (preventing the timetable from collapsing due to late arrivals will result in charging periods much shorter than layovers now) would require something like 40MWe, before inefficiencies are taken into account.
Whilst it would be normal to have only a small fraction of platforms charging at once, it is entirely possible that whilst recovering from disruption with a procession of trains arriving that every platform could be drawing charging load at once. Which means you could be looking at over 500MWe peak demand.

You would struggle to provide that kind of charging load without 50kV or even 100kV supplies to the trains. Even 40MWe at 25kV is going to come out over 1600A after efficiencies are taken into account.

I'm not arguing that battery powered trains are at all feasible, just that faster and faster charging of vehicles will happen as it makes everything more efficient.

Forgive me if I don't find this future with enormously varying electricity prices particularily appealing.
The poor spending the winter praying for windy weather so that they can afford heat and light, or even to be able to cook dinner, sounds rather grim to me.
Minute to minute smart metering, and thus the renewables that require it, are possibly the greatest threat to the living standards of less fortunate members of the society in decades.

The Economy 7 on steroids aspect will apply more at a grid level, as it does today. Most electric vehicle charging will be done at dedicated stations where grid supplies and billing can be done at a commercial scale. The future is for there to be times of incredibly cheap or even negative energy cost provided by renewable surpluses, and then occasional spikes in price when demand exceeds supply. If Elon Musk has his way then PV roof tiles will be the same price or cheaper than standard roof slate, so every new and rebuilt roof in Britain will have electricity generating capacity. To manage that efficiently you need energy storage, all of which will work to balance out the cost of domestic power and make it comparable to today.

 

[AM9]

I said the local distribution which is designed with a large diversity. For example a typical house fuse is 80amp ~ 20kw but the local distribution is not rated anything like that so if say several Nissan leafs with 28kw batteries where plugged on at the same time the sub station would overload.
I read a company in London wanted to introduce a fleet of electric vans but couldn't because of this very problem. The 51 electric buses just introduced needed a new 11kv feeder and substation making the economics very shaky.
This is true of any future trains where all the energy consumed during the days running of all the trains has to be put back in a short time requiring a lot of infastructure either oversized feeders or even more batteries.
K
K

All this talk of 28kW batteries is wrong. The batteries fitted to current models are 24 or 30 kWhours. That is their capacity, but the load on the charging supply depends entirely on the charging rate, the level from which they are charged and the maximum level to which they will be charged. Nissan themselves advise not regularly charging them to more than 80% capacity, saying that it has a negative impact on battery life.
The majority of chargers used domestically are rated at about 6-7kW, allowing them to be linked to a standard (dedicated) 32A circuit and charge a fully discharged battery in about 6 hours. If it was to become widespread as e-cars gained popularity, there would be similar supply load characteristics to domestic electric storage heating where loads are determined by the previous day's use. On warmer winter days, the heat requirements are a fairly short top-up at the beginning of the low cost tariff period. On colder days the demand goes deeper into the night. Owing to the higher relative cost of electric power over gas, storage heating is becoming less popular, but the distributors are well versed in both demand management and fulfilment. Car use for many would follow similar patterns except that bad driving conditions (e.g. cold weather) would more likely lead to an overall reduction in battery drain through reduced mileage.
Of course there will be the few 'battery heads' who go for the industrial chargers at their homes, but that might attract special tariffs outside the normal domestic ones and more like commercial restrictions where punitive charges are applied to peak loads during times of distribution system stress. With intelligent load monitoring, these installations could actually be remotely switched off at times.
The key to all e-car acceptability is the maximum availability of renewable power, - even if it does spoil some peoples view, - Goring Gap types, get ready to whinge!

 

[highdyke]

Cars are slow and always will be. It is inherent in the transport mode.

Indeed and relatively low capacity. We're still going to need public transport all I'm saying is I can see motoring groups using the diesel train v fast charge electric car (run on renewable energy) as a stick to beat the railway if we're not careful.

 

[superkev]

All this talk of 28kW batteries is wrong. The batteries fitted to current models are 24 or 30 kWhours. That is their capacity, but the load on the charging supply depends entirely on the charging rate, the level from which they are charged and the maximum level to which they will be charged. Nissan themselves advise not regularly charging them to more than 80% capacity, saying that it has a negative impact on battery life.
The majority of chargers used domestically are rated at about 6-7kW, allowing them to be linked to a standard (dedicated) 32A circuit and charge a fully discharged battery in about 6 hours. If it was to become widespread as e-cars gained popularity, there would be similar supply load characteristics to domestic electric storage heating where loads are determined by the previous day's use. On warmer winter days, the heat requirements are a fairly short top-up at the beginning of the low cost tariff period. On colder days the demand goes deeper into the night. Owing to the higher relative cost of electric power over gas, storage heating is becoming less popular, but the distributors are well versed in both demand management and fulfilment. Car use for many would follow similar patterns except that bad driving conditions (e.g. cold weather) would more likely lead to an overall reduction in battery drain through reduced mileage.
Of course there will be the few 'battery heads' who go for the industrial chargers at their homes, but that might attract special tariffs outside the normal domestic ones and more like commercial restrictions where punitive charges are applied to peak loads during times of distribution system stress. With intelligent load monitoring, these installations could actually be remotely switched off at times.
The key to all e-car acceptability is the maximum availability of renewable power, - even if it does spoil some peoples view, - Goring Gap types, get ready to whinge!

Yes I meant KW/hr rather than just kw.
I think if you buy some electric cars you get a free high capacity charger which particularly with the next generation of cars having larger batteries could sap the strength of the local cabling and substation if there where many used..
K

 

[highdyke]

It's looking increasingly likely GW electrification may be redundant as before it's even rolled out...

http://www.techworld.com/personal-t...cars-that-charge-in-minutes-possible-3651281/

Electric cars that charge in minutes could be on the horizon after breakthrough supercapacitor discovery
Battery limits remain the biggest barrier to the commercial success of electric cars. New research has revealed supercapacitor potential that means next generation batteries could soon overcome this obstacle.

 

[coppercapped]

Yes I meant KW/hr rather than just kw.
<Snip>
K

It is not kilowatts per hr, which is what the "/" symbol you used means, but kilowatt-hours - the result of kilowatts times hours.

This is not pedantry - there is a fundamental difference between the two units.

 

[daikilo]

So we need a concept which takes a ~constant power-feed into a base storage unit which then provides flash charge to individual vehicles as required. Less efficient no doubt but may avoid oversizing feeds for the peak case.

 

[HSTEd]

So we need a concept which takes a ~constant power-feed into a base storage unit which then provides flash charge to individual vehicles as required. Less efficient no doubt but may avoid oversizing feeds for the peak case.

That solves your feed size problem but increases the size of the total installed battery capacity rather drastically - as you need the batteries in the cars and then batteries on the grid. And charging operations are not 100% efficient. So stacking multiple inefficencies like that is somewhat problematic. Distribution capacity costs something like $50/kVA, which is probably still cheaper than massive battery banks.

 

[route:oxford]

With smart metering we're going to see Economy 7 on steroids

My parents have had it since the 60s. It's called "Economy 10".

 

[AM9]

Yes I meant KW/hr rather than just kw.
I think if you buy some electric cars you get a free high capacity charger which particularly with the next generation of cars having larger batteries could sap the strength of the local cabling and substation if there where many used..
K

AFAICS, the only free chargers greater than a single 32A circuit can supply are the Teslas (10/20kW) and some Mercedes (10kW). I would suspect that with the arrival of universal smart metering, that any large single-load greater than 10kW would cause the meter to alert the distributor of a non-domestic load characteristic. The default circuit rating of a domestic circuit is currentlyt 100A. To make 20kW charging viable, a greater circuit capability would be almost essential. This would probably attract a tailored tariff which allowed the supplier to limit the demand of that user if it prejudiced other local consumers' supplies. Smart meters have a lot more potential than just telling the consumer how much their instataneous load is costing or avoiding the need to send meter readers door to door.

 

[HSTEd]

The Economy 7 on steroids aspect will apply more at a grid level, as it does today. Most electric vehicle charging will be done at dedicated stations where grid supplies and billing can be done at a commercial scale.

Why?
They can charge their car at home whilst they sleep and avoid this trip to a charging station.

The future is for there to be times of incredibly cheap or even negative energy cost provided by renewable surpluses, and then occasional spikes in price when demand exceeds supply.

Negative supply only exists because of subsidy market distortions which in the glorious renewable future will probably not continue indefinitely otherwise you end up with the mess than is the German energy market.

If Elon Musk has his way then PV roof tiles will be the same price or cheaper than standard roof slate, so every new and rebuilt roof in Britain will have electricity generating capacity.

If Elon Musk has his way I will fly to work on a domesticated Sus Aeronauticus.
Not to mention that summer electricity generating capacity is effectively worthless and solar in the winter has a capacity factor in single digit percent and peak demand occurs in the dark.

 

[AndrewE]

So we need a concept which takes a ~constant power-feed into a base storage unit which then provides flash charge to individual vehicles as required. Less efficient no doubt but may avoid oversizing feeds for the peak case.

"Flash" might be the defining feature... People need to recognise that trains are heavy and when they go fast they use even more power. (Our) Pendolinos are rated at 5.95 MegaWatts (according to Wikipedia - continuously) so I can't imagine anything like that being charged up quickly without vapourising the power supply equipment! I know that is an extreme example, but think of the power used by a 12-car EMU crush-loaded on a stopping service and then you see that you have the same problem of power-transfer in a limited time.

It might work for light-rail (flimsy vehicles) recharging at every (frequent) platform, but I can't see it being a goer on heavy rail...

 

[NotATrainspott]

Why?
They can charge their car at home whilst they sleep and avoid this trip to a charging station.

1. Most people won't own a car. Hiring a self-driving vehicle will be cheaper for most people, since most cars sit around doing nothing but depreciating most of the time. If you don't own it, it'll go and charge itself up at some convenient place with a fast charger. The relative cost of owning a car will go up when people realise that it's quite nice not using land for parking spaces.

2. If you do choose to own your own, then it'll be able to drive itself to charge up somewhere convenient when you're not using it. The line between ownership and rental will be rather blurry, as some people who own a car would choose to have it park somewhere else and come and pick them up when they want.

Negative supply only exists because of subsidy market distortions which in the glorious renewable future will probably not continue indefinitely otherwise you end up with the mess than is the German energy market.

The PV roof slates and other entirely passive generation methods will mean that negative prices will be common. Eventually every roof in Britain will need replacement, at which point using PV tiles will be a no-brainer. Unlike the Americans we don't have air conditioning units to soak up electricity on hot sunny days. If there is a sunny day then it's entirely plausible that the static generating supply will exceed demand. This is the time when energy storage becomes financially worthwhile on a major scale.

If Elon Musk has his way I will fly to work on a domesticated Sus Aeronauticus.
Not to mention that summer electricity generating capacity is effectively worthless and solar in the winter has a capacity factor in single digit percent and peak demand occurs in the dark.

Peak demand does occur in the dark, which is why the economics point to energy storage as the solution. All that surplus electricity during the day can and will be stored for when it's needed.

The base load energy supply will end up being provided by combined heat and power natural gas plants near to and within built-up areas. Natural gas is a reasonable energy storage mechanism, is the least damaging of all hydrocarbons and can be produced through a variety of means including anaerobic digestion of biological waste. In the worst case scenario of the wind not blowing and the sun not shining we can efficiently fire up natural gas plants using stored supplies, as well as using other non-variable renewables like tidal, geothermal and hydro power.

 

[HSTEd]

1. Most people won't own a car. Hiring a self-driving vehicle will be cheaper for most people, since most cars sit around doing nothing but depreciating most of the time. If you don't own it, it'll go and charge itself up at some convenient place with a fast charger. The relative cost of owning a car will go up when people realise that it's quite nice not using land for parking spaces.

So where are all these cars charging going to be? And what will people do when they discover that there car sharing agreement has no vehicle available for them because its peak demand and everyone is using them to go on holiday?

Cars are cheap, you can get a new car for less than £6k easily and they can last for years, especially if you don't drive it that much.

2. If you do choose to own your own, then it'll be able to drive itself to charge up somewhere convenient when you're not using it. The line between ownership and rental will be rather blurry, as some people who own a car would choose to have it park somewhere else and come and pick them up when they want.

And unless it can park nearby then people will be upset when the car takes a long time to arrive as it works its way back to them.
The idea of universal taxi services sounds nice until it becomes clear just how likely that peak times are to cause the system to collapse.

The PV roof slates and other entirely passive generation methods will mean that negative prices will be common.

So people will decide to just pay people to take the electricity away?
Why would they do that when they can either just disconnect the generation or, if doing so incurs additional maintenance due to the power cycle, connect some resistor grids connected next to the generation system.
Negative prices only exist because of state mandated subsidies and taxes on electricity use.

Eventually every roof in Britain will need replacement, at which point using PV tiles will be a no-brainer. Unlike the Americans we don't have air conditioning units to soak up electricity on hot sunny days. If there is a sunny day then it's entirely plausible that the static generating supply will exceed demand. This is the time when energy storage becomes financially worthwhile on a major scale.

So PV tiles containing numerous valuable materials will become cheaper than actual roof tiles made from material I can literally dig out of the ground almost anywhere?
That is nonsensical and people only believe it because its bloody Elon Musk who says it - the man who got lucky with PayPal and has only managed to achieve two things since then: a car company that haemmorhages hundreds of millions of dollars a year and a satellite launch company that has only managed to take American launch systems from horrifyingly uncompetitive to marginally competitive with European and ex-Soviet systems.

 

[superkev]

So where are all these cars charging going to be? And what will people do when they discover that there car sharing agreement has no vehicle available for them because its peak demand and everyone is using them to go on holiday?

Cars are cheap, you can get a new car for less than £6k easily and they can last for years, especially if you don't drive it that much.

And unless it can park nearby then people will be upset when the car takes a long time to arrive as it works its way back to them.
The idea of universal taxi services sounds nice until it becomes clear just how likely that peak times are to cause the system to collapse.

So people will decide to just pay people to take the electricity away?
Why would they do that when they can either just disconnect the generation or, if doing so incurs additional maintenance due to the power cycle, connect some resistor grids connected next to the generation system.
Negative prices only exist because of state mandated subsidies and taxes on electricity use.

So PV tiles containing numerous valuable materials will become cheaper than actual roof tiles made from material I can literally dig out of the ground almost anywhere?
That is nonsensical and people only believe it because its bloody Elon Musk who says it - the man who got lucky with PayPal and has only managed to achieve two things since then: a car company that haemmorhages hundreds of millions of dollars a year and a satellite launch company that has only managed to take American launch systems from horrifyingly uncompetitive to marginally competitive with European and ex-Soviet systems.

Typical solar power is around ave 60w per sq m depending how sunny it is. That's a lot of roof for not many kw. The economics of pv's very shaky.
K

 

[NotATrainspott]

So where are all these cars charging going to be? And what will people do when they discover that there car sharing agreement has no vehicle available for them because its peak demand and everyone is using them to go on holiday?

Charging locations will be built wherever is most appropriate, just as with petrol stations today. Electricity is relatively easy to come by and with the way that renewables work, it's not a given that rural locations will have a harder time providing the necessary power supplies.

Cars are cheap, you can get a new car for less than £6k easily and they can last for years, especially if you don't drive it that much.

A car requires insurance, maintenance, incurs depreciation, requires space for parking (housebuilders will jump at the opportunity to no longer build driveways and to cram in even more homes in a plot; meanwhile, more and more people will be living in towns with limited parking due to the newfound convenience of modern life) and is otherwise a waste of time and effort whenever you're not driving it.

There is absolutely no way in which a driverless electric taxi would not be cheaper than any private motoring.

And unless it can park nearby then people will be upset when the car takes a long time to arrive as it works its way back to them.
The idea of universal taxi services sounds nice until it becomes clear just how likely that peak times are to cause the system to collapse.

1. Self-driving taxis will do whatever is the most efficient according to the wonderful algorithm which will distribute them across the country. A taxi company that wasn't close enough to you to be able to pick you up within a few minutes would be one that would lose your business.

2. Current peak periods are going to be pretty much irrelevant when work ends. If you use your UBI to do what you want, even open your own business, then you're going to have the flexibility to travel when you like. This isn't going to result in the end of public transport as the 'weekend economy' is more than able to fill up capacity already. TfL is finding that it simply can't run a basic weekend service any longer as so many people want to travel for leisure. If there's no such thing as the peak period any more, then it'll be perfectly possible for supply to match demand pretty well across the whole day/year.

So people will decide to just pay people to take the electricity away?
Why would they do that when they can either just disconnect the generation or, if doing so incurs additional maintenance due to the power cycle, connect some resistor grids connected next to the generation system.
Negative prices only exist because of state mandated subsidies and taxes on electricity use.

Let's say you're one of the many Britons who own a home with a PV roof. When the sun starts shining, your roof and those of everyone else nearby will start producing lots of electricity whether you like it or not. Once the roof is there, there's no operational cost whatsoever. When the sun is not shining, you have to pay for electricity from the grid. If there's over-supply, then all the electricity that your roof is generating is going to waste. You can work out that since prices will be higher at other times, there is a financial case to be made in investing in energy storage, so that all that wasted energy can be stored and so you don't have to pay for electricity when it does have a cost.

So PV tiles containing numerous valuable materials will become cheaper than actual roof tiles made from material I can literally dig out of the ground almost anywhere?
That is nonsensical and people only believe it because its bloody Elon Musk who says it - the man who got lucky with PayPal and has only managed to achieve two things since then: a car company that haemmorhages hundreds of millions of dollars a year and a satellite launch company that has only managed to take American launch systems from horrifyingly uncompetitive to marginally competitive with European and ex-Soviet systems.

Yes.

People thought that Jeff Bezos was a lunatic too, with his company that didn't make any money. Is anyone laughing now?

 

[JamesRowden]

It's looking increasingly likely GW electrification may be redundant as before it's even rolled out...

http://www.techworld.com/personal-t...cars-that-charge-in-minutes-possible-3651281/

I think that the article might have overstated story. Supercapacitors can be charged in seconds. The very low energy density of supercapacitors is the reason that batteries are favoured for cars. The discovery seems to be supercapacitors of greater energy density than produced before, but I doubt that the energy density is anywhere near that of batteries. And the prototype battery train only had a maximum range of 50 miles between charges. The advantage of the supercapacitors for electric cars would be that the owner doesn't need to wait a long time for their car to charge. However the owner would be required to recharge the supercapacitor frequently. Using a combination of a battery and a supercapacitor would mean that one could get a compromise between the benefits of both. The battery would allow the vehicle to travel a section of the journey which has relatively great distance between charging events so long as there are frequent charging events (to charge the supercapacitor) for the majority of the journey.
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This system could be applied to railway. I'll give the Brighton-Ashford service as an example:

• The battery and supercapacitor is recharged on the Ore-Brighton-Ore section of the journey using the third rail supply.
• Some ultra-high power supercapacitor chargers are fitted above the train at the platforms at some of the stops of the service to recharge the supercapacitor during those stops on the Ore-Ashford-Ore section. The battery is also partially recharged at those stops.
• The supercapacitor is used to power the train on non-electrified sections until the supercapacitor is discharged and the battery takes over. Energy from the supercapacitor can be used to recharge the battery if not all of the supercapacitor energy is going to be used before the next charging point.

 

[LDECRexile]

I got quite excited by the rechargeable train experiment which took place near Harwich, which was apparently deemed a success, but which has gone rather quiet since.

If it was a goer I could see lots of routes where it might be used, such as Manchester to Wigan (currently being electrified) then on to Southport on batteries or Euston to Carnforth then to Barrow-in Furness on batteries.

Supercapacitors as well as or instead of batteries as discussed here are in use in China, eg : http://www.railwaygazette.com/news/single-view/view/guangzhou-supercapacitor-tram-unveiled.html so this is not fantasy future technology. Improvements and breakthroughs are welcome in my book.

I then read a piece by Ian Walmsley in Modern Railways (sorry, I haven't got a proper ref) which demolished the whole lot, not on the science, but the economics.

If I got him right there are the following inherent problems:

1. lugging batteries round for intermittent use incurs similar costs (extra juice, wear and tear etc) as hybrid trains
2. batteries can only be recycled so many times, after which they are scrap. If (say) recycle patterns result in a five year life then new batteries every five years becomes the best case. Batteries on the scale needed are not cheap
3. batteries and associated on-board kit are something else to go wrong. A "pure" electric train has none.

His conclusion was that it would end up costing about as much to electrify Wigan-Southport as to provide a bespoke fleet.

I see the future as renewable electric, but to make it work I reckon we've got to expand our sources of supply. For example, I believe there are arrangements between some countries (??Norway, Denmark & Netherlands??) to pool green juice, so Norway's hydro takes the strain on cold, still nights and so on. Morocco is building mega solar generation, if that chipped in we would move further towards something sustainable and practicable.

I think I saw that the trams in Birmingham are going to use batteries for their next extension, thereby avoiding OHE in town. They considered supercapacitors but decided they weren't strong enough for the gradients involved. This rather surprised me as I don't recall central Brum as hilly.

 

[Elecman]

I said the local distribution which is designed with a large diversity. For example a typical house fuse is 80amp ~ 20kw but the local distribution is not rated anything like that so if say several Nissan leafs with 28kw batteries where plugged on at the same time the sub station would overload.
I read a company in London wanted to introduce a fleet of electric vans but couldn't because of this very problem. The 51 electric buses just introduced needed a new 11kv feeder and substation making the economics very shaky.
This is true of any future trains where all the energy consumed during the days running of all the trains has to be put back in a short time requiring a lot of infastructure either oversized feeders or even more batteries.
K
K

DNOs based the average house demand at 4KW when planning the distribution system. Your 80 amp fuse gives a capacity of just over 18Kva.