|
Quite!
Set the scene on Friday or Saturday just gone - stinking hot (my air con is dead at the mo and i had to sit on the M6 while an accident was cleared up - pff!) and the interior of your electric vehicle is like an oven. So you put the air con on. It drains the battery and you stupidly didn't bring a back up. You are then stuck in the middle of the m'way causing a blockage. You are in company, as there's a few other electric cars stopped dead around you too.
Ah well at least it'd stop people getting up to the Lakes when it's nice out and clogging up Ambleside!
|
Quite!
Set the scene on Friday or Saturday just gone - stinking hot (my air con is dead at the mo and i had to sit on the M6 while an accident was cleared up - pff!) and the interior of your electric vehicle is like an oven. So you put the air con on. It drains the battery and you stupidly didn't bring a back up. You are then stuck in the middle of the m'way causing a blockage. You are in company, as there's a few other electric cars stopped dead around you too.
Ah well at least it'd stop people getting up to the Lakes when it's nice out and clogging up Ambleside!
I got stuck for 3 hours on the M6 once near Corley Services. Several cars with conventional engines didn't get going again - I think the Lexus LS driver had spent most of the time playing "chair goes up; chair goes down" with the 94 speaker surround stereo playing soothing tunes :-)
|
|
|
|
|
Electric cars will be suitable for some, though the initial cost and practicality will be a big problem for many. For us, living in a rural location the biggest factors will be the range and size of the vehicle. We need our main vehicle to be able to regularly transport two or three adults and two kids, dogs,luggage etc up to 200 miles winter and summer. Even our second family vehicle needs to do 70 miles in one hit. I can't see us owning an electric vehicle in the next couple of decades.
|
|
The battery packs used in electric cars are not the sort of thing you can have "backups" for. It's a seriously big load of cells all built-in, not like an ordinary car battery ...
|
|
|
|
You will simply pull into a service station and change batteries a system already in its trial phase in Germany with DB having built the factories for the batteries and now is putting together the infrastructure,the growth will be driven by demand like anything in the commercial world.
|
|
It's a fuel cell rather than a battery but advances have been made in shrinking them so that spares may be carried. The cell is basically a container of some electrolyte, with an anode and cathode in there. The anode strips off the electrons from the fuel (hydrogen), so you get net electric current across the 'battery'. At the cathode, recombination occurs and you get usually water as a waste product.
|
|
Are you sure it's a fuel cell? How is the hydrogen stored? I thought that metal hydrides were currently little better than Lithium ion in terms of power density and that had knocked the entire 'hydrogen economy' scam on thehead.
|
|
|
|
|
What irritates me is all the tax breaks that electric cars get when the vast majority of their power comes from fossil fuel/nuclear. If they were that good they would compete with petrol/diesel on their own merit. They aren't so they need an unlevel playing field.
So basically thewell-heeled Islington set get generous tax breaks on a toy whilst everyone else gets fleeced. :(
If you compare them, on a like for like basis, they are only marginally more efficient than a good diesel!
|
|
Thats a Lu
Edited by Collos25 on 06/06/2011 at 15:11
|
|
I meant to say thats a Luddite approach
|
thats a Luddite approach
No it isn't. Electric cars are not a new idea-At the start of the 20th century, electric cars beat conventional Internal Combustion Engines in all areas other than range. The technology has over 100 years to develop and does not deserve subsidies or tax breaks.
Britain is already struggling to cope with electricity demand outripping supply and we can do without thousands of these tax dodging milk-floats adding to the problem.The 'zero emissions' is a myth too-they are coal fired and nuclear powered cars.
If we eventually do solve our electricity problem and have a surplus, the electricity could be used to make synthetic fuels (eg methanol) which would work just fine in an ordinary ICE without the hassle of expensive batteries/fuel cells.
|
|
I entirely agree. Something viable that we would recognise as a regular car came out in about 1966 (can't remember what sorry). We're still just playing with the tech at the mo. Although there are electric buses in St Helens.
Unthrottled is exactly right when he says that the cars' ultimate energy source is power stations; in my OP I said I wondered where all this extra eleccy is going to come from! I too dislike the incentives given to these vehicles - let's wait till they've proved themselves en masse eh? You get a £5k gov't grant if you buy a Nissan Leaf, for example. Also if I see one more Prius hammer it past me on the m'way at 100mph....!!
I'm pretty far from a Luddite and I do find the technology interesting, but I do wonder if we really oughtn't be looking at gasohol or something instead (I'm not sure I'm happy with biogas either!)
Or, let's go back to horses ;-P
|
|
When i said 'synthetic' I didn't mean bio. That's another sleight of hand eco trick that we can well do without. I was thinking more on the lines of Gas To Liquid (GTL) ie converting natural gas (methane) to methanol for convenience of storage. The gas that currents produces electricity could then we used for making liquids fuels-while stationary steam turbines would be nuclear powered.
I can (just) about see how a bus can store liquid hydrogen because the tank would be refilled at the depot every night. But with a boiling point of ~-160C, liquid hydrogen needs massive pressure, refrigeration, and fantastic insulation to remain liquid. Otherwise, you end up having to vent all your hydrogen to the atmosphere as it gradually warms up.
So many people get excited about 'new' ideas that aren't new at all. I've been in several seminars where a graduate trainee delivers a glossy powerpoint presentation on a world saving idea, only for a wizened old engineer to pipe up 'we tried that 40 years ago and it was a crock of s***'. Graduate trainee goes back to photocopying.
Uneven tax incentives don't make the best use of resources because an inferior idea can usurp a superior one due to the misplaced externality.
|
When i said 'synthetic' I didn't mean bio. That's another sleight of hand eco trick that we can well do without. I was thinking more on the lines of Gas To Liquid (GTL) ie converting natural gas (methane) to methanol for convenience of storage. The gas that currents produces electricity could then we used for making liquids fuels-while stationary steam turbines would be nuclear powered.
This approach would be very wasteful of natural gas. The fundamental is that IC engines in cars have very poor efficiency - Somebody else will know it more accurately but I have the figure of 25% in my head, but this will only be achieved at constant speed, not in real-world driving with the engine speed changing.
Whereas Siemens have just hit 60% electrical efficiency in a gas turbine, or about 75% total efficiency if the heat is used in a CHP scheme.
Nuclear is, on balance, a technology the UK probably has to do, but it's not a simple either/or with something like gas for now. Gas (and coal) can be started/stopped/modulated well to follow demand (which is always changing), whereas nuclear is optimised to run basically at 100% output the whole time.
|
|
Well there's at least two of us on here that work/have worked in the nuclear industry. Personally, I do think it's the way to go and I think the knee-jerk reaction of Germany (a country more likely than the UK to go for eleccy cars) to Fukushima is silly and they'll regret it.
Nuclear plants run at a similar efficiency level to fossil fuel plants; about 35%. Better for the newer ones but not much. The biggest issue with all plants is that the heat output is lost to atmosphere. Nuclear's advantage lies in its lower emissions. Also, a nuclear plant releases considerably less radioactive material into the environment that a fossil fuel plant, but regulation is very tight in the UK and rightly so.
|
|
thats a Luddite approach
No it isn't. Electric cars are not a new idea-At the start of the 20th century, electric cars beat conventional Internal Combustion Engines in all areas other than range. The technology has over 100 years to develop and does not deserve subsidies or tax breaks.
Britain is already struggling to cope with electricity demand outripping supply and we can do without thousands of these tax dodging milk-floats adding to the problem.The 'zero emissions' is a myth too-they are coal fired and nuclear powered cars.
If we eventually do solve our electricity problem and have a surplus, the electricity could be used to make synthetic fuels (eg methanol) which would work just fine in an ordinary ICE without the hassle of expensive batteries/fuel cells.
We're not struggling to cope with demand outstripping supply right now. Electricity demand is down, several old power stations have been mothballed and average asset utilisation is not much above 50%. Not a great figure for a "mass production" industry.
You also need to compare like with like. The real-world CO2 performance of EVs seems to be around 75 g/km. Which isn't much better than say a Prius at 89. But that's a real world vs synthetic test. The real economy of a Prius is probably much worse, and probably ditto for a Bluemotion/Econetic. Auto figures also need to go up a bit to account for refining & transport losses.
Why would you take precious electricity and convert it at low efficiency to a liquid fuel to burn at low efficiency in an IC engine? The key feature of electric motors is very high efficiency.
|
We're not struggling to cope with demand outstripping supply right now. Electricity demand is down, several old power stations have been mothballed and average asset utilisation is not much above 50%. Not a great figure for a "mass production" industry.
Sorry, but that's just plain wrong. Britain has a shortage of electricity generating capability. Quite simply we use more than we generate and have to import the difference.
A good diesel engine is ~40% efficient at full load, 35% efficient at 50% load and 30% at 25% load. Call it ~30%
The average efficiency of a thermal power station is about 50%. Then there's a 5% drop across the national grid, 15% loss battery charging/discharging loss, and the electric motor is ~80-85% efficient at say 50% load. Compound the efficiencies and you get ~35%, so better than a diesel but not by much. Everyone says 'electric motors are really efficient' but that's because it hides the inefficiencies from all the extra thermodynamic processes.
CHP is an old idea but unless you want a power station right outside your house, it isn't coming anytime soon. It's not practicable to transport hot water over long distances.
The point about manufacturing methanol from natural is NOT that it is eneregy efficient-it isn't. The point is that it would provide a good feedstock for methanol. The energy would come from the nuclear power plant, not the natural gas-assuming there was a glut of electricity. Since there isn't the question is academic!
Edited by unthrottled on 09/06/2011 at 22:33
|
We're not struggling to cope with demand outstripping supply right now. Electricity demand is down, several old power stations have been mothballed and average asset utilisation is not much above 50%. Not a great figure for a "mass production" industry.
Hmmm... ok. Bare with me:
"Mass production": Well it's asset intensive, with highly optimised systems converting inputs to outputs with maximised efficiency. The problem as we all know is storage - you can't leave electricity parked on a disused RAF base until somebody wants it.
http://www.bloomberg.com/news/2011-03-03/centrica-halts-four-gas-fed-power-stations-for-a-year-1-.html
To me, this would suggest generation is not in short supply, nor anticipated to be this winter? I think the point you're making (that I agree with) is that we may be storing up trouble for a few years as LCPD coal plants run out of hours even more quickly. But if capacity was tight, power prices would give a spark spread that would make Centrica's actions difficult to explain.
Turning to DUKES to justify my "not much above 50%"
http://www.decc.gov.uk/assets/decc/Statistics/publications/dukes/348-dukes-2010-printed.pdf
Total electricity supplied (2009) = 379 TWh
Average demand = 379000/8760 = 43.3 GW
Total Generation Capacity = 85.337 GW
Average asset utilisation ratio (AUR) = (43.3/85.337) * 100 = 50.69 %
Unfortunately the numbers do not lie, and there are is a lot of generation capacity that spends a lot of time sitting around doing not much, particularly when there's obviously baseload and must-run CHP with very high capacity factors & utilisation.
The AUR is likely to fall significantly as more wind is switched on but the capacity needs to be retained as wind is "a bit variable" :-). Hence Electricity Market Reform, capacity payments and (finally to bring the conversation on-topic) people waxing lyrical abou t the potential of vehicle-to-grid.
Regards
|
|
You're assuming demand is roughly constant . It isn't.
You're assuming all plants are online 100% of the time. They aren't.
Hydro electric power is used as instant demand and adds a lot to the generating capacity (GW), but very little to the total electricity supplied (TWhr). This is because the reservoirs are quickly exhausted and take a long time to refill.
|
You're assuming demand is roughly constant . It isn't.
You're assuming all plants are online 100% of the time. They aren't.
Hydro electric power is used as instant demand and adds a lot to the generating capacity (GW), but very little to the total electricity supplied (TWhr). This is because the reservoirs are quickly exhausted and take a long time to refill.
The calculation is looking at averages, agreed. But at the end of the day, regardless of whether a power station is at full chat or mothballed, it's still an asset on somebody's balance sheet that is either *being utilised* (generating or getting paid to provide reserve) or *not being utilised* and earning nothing. We got into this because it was claimed that we had a massive generation shortfall. My simple calculation with accurate figures shows this to be untrue.
Of course on a summer night we're going to see what, 20-25 GW and maybe 60-65 GW at winter peak. And the market is designed to deliver an adequate capacity margin over forecast demand - I'm sure a lot of generation is offline currently. Of course we'll run out of power (and T&D infrastructure) if we have millions of EVs trying to charge at 5pm on a cold, still, winter's day and that is why the industry is talking about shifting EV demand, initially with tariffs (as has been done with storage heaters for many years).
So there is plenty of capacity, and as long as we don't do anything stupid with EV charging, then they aren't going to be the cause of the lights going out any time soon (particularly if they remain niche due to range anxiety etc)
Hydroelectric is only one technology that is used to balance the system, and one which sadly has limited growth potential in the UK.
|
|
What other systems are there? I can't think of many other forms of eleccy generation other than hydro that kick in at a few seconds notice. The peak demand is a big problem and average usage masks this.
|
|
We're not struggling to cope with demand outstripping supply right now. Electricity demand is down, several old power stations have been mothballed and average asset utilisation is not much above 50%. Not a great figure for a "mass production" industry.
Sorry, but that's just plain wrong. Britain has a shortage of electricity generating capability. Quite simply we use more than we generate and have to import the difference.
A good diesel engine is ~40% efficient at full load, 35% efficient at 50% load and 30% at 25% load. Call it ~30%
The average efficiency of a thermal power station is about 50%. Then there's a 5% drop across the national grid, 15% loss battery charging/discharging loss, and the electric motor is ~80-85% efficient at say 50% load. Compound the efficiencies and you get ~35%, so better than a diesel but not by much. Everyone says 'electric motors are really efficient' but that's because it hides the inefficiencies from all the extra thermodynamic processes.
CHP is an old idea but unless you want a power station right outside your house, it isn't coming anytime soon. It's not practicable to transport hot water over long distances.
The point about manufacturing methanol from natural is NOT that it is eneregy efficient-it isn't. The point is that it would provide a good feedstock for methanol. The energy would come from the nuclear power plant, not the natural gas-assuming there was a glut of electricity. Since there isn't the question is academic!
The reason for the imports is more to do with energy trading. We have a power system with a high opex based on fuel, whereas in France it's high capex as it's mostly nukes have with low marginal costs. Therefore it is probably cheaper to meet some UK demand with cheap French nuclear electrons rather than expensive gas/coal powered British ones.
But if dry weather continues we'll be raiding the coal piles to export over the interconnector as the French nukes on the rivers get constrained off because of low river levels.
Net imports in 2009 were only about 3 TWh (i.e. 1%). This obviously counts as a British manufacturing success story! Particularly since 3 big generators are UK-based plcs!
Agree that EVs do not make a lot of sense in CO2 terms if you keep today's generation fleet. But you will know where the policy push is going. With wind turbines efficiency (i.e. power out/wind energy in) is not really the issue because your input is free, £/kWh and £/kW installed are the key metrics.
CHP seems to work OK in most of Scandinavia - there are city-wide heat networks all over the place. Agree you wouldn't retrofit to UK stations in the middle of nowhere like Drax, but there's quite a lot of growth in smaller-scale natural gas CHP. Thinking about CHP, did you see this? Can you imagine the reaction to an incinerator like this in the UK?
http://www.telegraph.co.uk/earth/earthpicturegalleries/8313380/A-waste-to-energy-power-plant-in-Denmark-that-blows-smoke-rings-and-has-a-ski-slope.html
|
|
|
|
|
|
How little you know about electrcity generation.
|
How little you know about electrcity generation.
confused.com.
Can you be a bit more specific and then we have some chance of dialogue.
Thanks.
|
|
|
|
|
|
|
Some are Li-ion type. Some are hydrogen, which they're trialling on buses as well. Here's a list of vehicles with H cells: en.wikipedia.org/wiki/List_of_fuel_cell_vehicles and have a look at the HICEVs as well.
There's also the proton exchange membrane fuel cell which works roughly as I described the H-cell. It uses graphite channels for the electrolyte to run along, so that it's always in electrical contact. It'll be b***** carbon nanotubes next...!!
|
|
Knowing our luck the secret to giving leccy cars huge range and endurance will turn out to be exclusively Saudi Arabian sand.
That or an enormous flexcord .........
Thanks but I'll stick with LPG ....bring on the shale gas! Kerwhumpf!
|
|
That would be fracking awesome....
|
|
|
|
|
|
|
|
