Ultracapacitors are my bet for the way to replace gasoline fueled vehicles. Hydrogen is just not dense enough even in hydrides and there is no infrastructure for it. Batteries are too heavy, too short lived, have complex temperature and charging requirements to maximize life, take too long to charge and are not improving quickly enough. Synfuels are possible but require a lot of new plants and the fuel is going to be expensive.
Electricity, on the other hand, is available everywhere. Once you have the ability to connect a plug and ‘fuel’ your vehicle at least as quickly as you currently do and have a range equal or greater than you now have with gasoline or diesel, there is simply no contest.
The electric car, with a motor on each wheel, gives neck-snapping acceleration, handling and braking that are awesome and all in a much simpler package. No differential, no coolant system, no transmission, no high temperature combustion, no crankshaft, piston rings or rockers, no oiling system… in the ultimate electric car there is little more than batteries, power distribution, four motors and a bunch of computers to control them. As much as I loved my old MGB, the internal combustion engine is unlikely to outlast the middle of the century. It simply will not be able to compete.
A Tesla in every garage… I can deal with that.
I don’t think it’s that obvious.
I currently use about 9000 kWh of electricity and 1500 liters of petrol a year. Petrol contains about 10 kWh of energy per liter, so to replace that with electricity would use another 15,000 kWh, more than doubling my current use. OK, lets assume that batteries and electric motors are more efficient than petrol motors and call it double, for argument’s sake.
I’m paying about NZ$0.20/kWh for electricity and NZ$2.20 for a liter of petrol. So while energy may be cheaper in the form of electricity, it’s not radically cheaper that way. Maybe I’ll decide to get an electric car, based on those figures. (let’s ignore the fact that I buy cheap ten year old cars and it’ll be a long time before I can buy an electric car used cheaply — especially with still working batteries)
But what happens if everyone switches to electric cars? The electric grid will collapse! We’ll need a lot more transmission lines, and a lot more power stations. There aren’t any more rivers to dam. Oil or gas power stations largely just transfer the thermal inefficiency from under my bonnet to a central power station. Maybe they can do something useful with the waste heat, but then so do I in my car in the winter.
No doubt nuclear makes the most sense. That’ll be an uphill battle, especially as we don’t have any here yet.
But in any case, using electricity for transport is going to require just as many new plants as synfuels would PLUS a new distribution system. Synfuels can just reuse the existing distribution system.
Here’s a prediction. I dont’ know if it’s entirely serious, but I think it’s plausible:
Countries that can build a lot of nuke power stations with minimal legal fuss and minimal expense (and possibly minimal safety) will do so, use them to run synfuel plants, and ship us the result in supertankers.
Try *that* with ultra capacitors.
You all know who I’m thinking of.
Depends how green your country is. Greens won’t be able to afford electric cars if we use your numbers… but electricity is in the range of US$0.10/kwh in DC area and that is a lot different. Also, if the ultracapacitors are as long lived as we think, and we take the known long lifetimes of electric motors and electronics… I suspect construction cost and maintenance costs can be driven quite low.
However, at $0.42/kwh, Pacifica California will not be a friendly place to own an electric car. The green meme contains an embedded self-extinction behavior.
What’s the difference between an ‘ultracapacitor’ and a battery that handles very fast charge and discharge rates? It may be slightly different materials technology but it’s doing the same thing.
“Electricity, on the other hand, is available everywhere.”
Not if Chris Huhne has his way, it’s not.
It’s available occasionally, in small quantities, when the wind blows – not too strongly.
I’m not a fan of electric cars Bruce but your numbers ignore the inefficiency of burning the petrol and turning it into forward motion.
You might get 90% out of an electric motor and 25-30% out of the IC car.
However most of these comparisons ignore the cost of capital. In the case of the electric car the cost of the batteries and their limited lifetime. Every time I do the numbers it costs 3 times as much to drive an electric car per kilometer as for petrol.
The lack of wear and tear on the electric is also possibly a furphy. The electric is heavier so wear on tyres , brakes, suspension, wheel bearings is likely greater. Modern IC cars basically run for a long time with minimal maintenance and essentially zero non scheduled maintenance(based on my 2000 Honda Accord, not an unusual car I think).
Mike: is the battery that heavy?
All of which is why an ultracapacitor wins hands down, at least eventually.
Batteries generate electricity through a chemical reaction that gives off positive and negative charges at the terminals. The negative charge is in electrons that flow through a completed circuit to neutralize the positive charge on the other pole. Some batteries have a reversible chemical reaction: if you apply an external current in the reverse direction, you drive the chemical reaction the other way and the battery ‘charges’. However, you will not recharge perfectly. The laws of thermodynamics require that some energy will be lost on each cycle. Batteries do not live forever without a replacement of their electrolytes, plates or whatever passes for them. Usually we do this by just pulling them out and discarding them.
An ultracapacitor does not produce electricity. There is no chemical reaction. It is nothing but a storage jar for electrons. The amount of charge you can store depends on the surface area of two opposite plates and the quality of the dielectric (seperator) between them. Lots of area means lots of room for electrons; a good dielectric means a higher voltage before arcing between plates and allows more charge to be piled up per unit area.
The energy loss mechanism that limits charging speed on a battery is the amount of heat generated by the inverse chemical reaction. In an ultracapacitor the only loss is internal resistance.
There is no question that an ultracapacitor can outperform in both charge time, instant power delivery and effectively ‘infinite’ lifespan. (Old fashioned high powered capacitors of various sorts last for decades. It would not surprise me if someone showed me one built in the 1930’s that was still in service in a factory or electric grid). There are no moving parts, no reactions that have to work reversibly. The ‘death’ mode for them is dielectric failure. This is what used to happen in your old TV’s in the high voltage power supply capacitors. Rarely happened even then in less than 10 years.
A discharged battery and end of life battery is a jar of chemicals, some dangerous (ie, don’t break open your lithium batteries in the presence of any source of an oxidizer. Things can get really warm in the neighborhood.)
A discharged ultracapacitor is a jar, It is a mechanical structure which is unlikely to be explosive, a fire hazard or toxic.
Capacitors have always been used in electronic circuits for places where you need to store and discharge at high speed. They are used in filter circuits, in AC to DC power supplies, as a means to block DC current, and many other purposes. They are the reason why your electronics fade into ‘off’ when you pull the plug. It was just that until recently (ie the last 10-15 years) no one thought of them as a replacement for batteries. You just could not get the combination of large plate area and high voltage dielectric that was needed to match a battery.
The MIT folk seem to be changing that. If they succeed, then we pull our worn out battery packs and their expensive charging control circuitry and cooling and heating circuits and replace them with the humble capacitor that has found it can change from Clark Capacitor to… Ultra Capacitor!
Mike – I wouldn’t include brakes on your list; driven carefully (and your typical EV driver is unlikely to be a hooligan) a Prius’ brakes last upwards of 100,000 miles due to the use of regenerative braking in most circumstances.
I’m also not convinced about the problem of limited lifetimes for the batteries. Again using a Prius as an example, as it’s similar technology that has been around long enough to draw some conclusions from, the battery pack can go for 200,000 miles with limited degradation, and can be replaced for less than $3,000. I imagine in a pure EV those numbers will be less favourable, but I’d be surprised if they’re terrible.
Having said that my wife has an Auris Hybrid and I’m unimpressed; sneaking out of car parks in EV mode is fun, but it only gets 5-6 mpg more than my much larger diesel Avensis Tourer, which doesn’t justify the price premium.
Hi Mike,
No, I mentioned that petrol engines aren’t as efficient in my second paragraph and also touched on it in the 4th paragraph where I mentioned that the waste heat from petrol engines is useful to heat the cabin of the car in winter, something that reduces the range and efficiency of electric cars by a significant amount because they have to run electric heaters or heat pumps.
Even allowing for the efficiency difference I might only be looking at an extra 5000 or so kWh (instead of 15000) to power my car, but that’s still more than a 50% increase in electricity consumption.
I think the Atkinson cycle engines being used in the hybrids are a bit more efficient too. As an “Atkinson effect” can be gained just with valve timing I suspect we might see that used in pure petrol cars in cruise mode too.
Yes Alisa the batteries are that heavy. Look up the mass of a Lotus Elise and the Telsa Sportster. They are really the same car, one with IC engine, one with electric.
PaulH , the Prius has a miniscule battery pack of NiMH type and uses only 50% of the maximum capacity in order to ensure long life. If you do this in pure electric it will have a range of maybe 5km. The pack has to be much larger (heavier) and must use more of the total capacity. I’ve had a ride in a Prius. Wonderful technological achievement but use the same drag reduction techniques in a Corolla and it would likely get not much worse petrol economy. The Prius costs twice as much as the Corolla. My friends Prius gets 5l/100Km driven gently and the Corolla we drove in NZ in March got 6.5L/100Km without any special care and without the low friction tyres, underbody pan lightweight crappy interior etc.
I’m still holding out for fuel cells myself. Traditional/semi-traditional fuels but much more efficient and many of the benefits of electric. Also the beaming of solar power from space.
alisa- there is a new electric Rolls-Royce on the market, which is as big as a regular Rolls, but is all electric! even with the best batteries available, they still only promise 200 kilometres maximum range, between 8-hour recharges! Batteries aint light yet!
Electric cars are much more efficient at using their energy to enable grandma to go shopping, but we dont have the infrastructure yet to charge all the cars. The key there is local power production and storage, rather than centralized mega-power plants and transmission lines. Another option is the mega-power plant that charges up truckloads of ultra-capacitors, and ships them out to ‘fueling’ stations all over the local area, which, instead of giving your car a charge, swap out your standard ultra-capacitor for a fully charged one, and off you go. Just like propane tanks for your BBQ. Fast, efficient, and infrastructure costs to implement are lower than almost any alternative.
I think many of you are making a mistake in assuming that electric charging stations of cars will cause a grid problem. It won’t. Even if Ultracapacitors are wonderful, it will take a couple decades before gasoline fueled cars are fully replaced, if ever. The charging stations will generate revenue that makes it in people’s interest to provide more charging stations and more electricity for them. Things just do not happen like turning on a light switch. Cost and availability of the charging stations will drive the adaptations of cars and vice versa.
How long did it take for cars to replace horses and their infrastructure? About 30 years or more. I expect nothing different in the switch from gasoline to electric.
Dale: time being available to solve the grid problem without disruption does not mean that the problem does not exist.
Electric cars will require more investment in the grid and in power stations than would otherwise be the case. *Significantly* more — not just a few percent.
That is a huge problem, given the vociferous opposition to building any new infrastructure that is currently present in advanced countries.
Far easier, politically, to use the existing fuel distribution infrastructure (supertankers, pipelines, trucks, tanks) and put the investment required into new facilities in developing countries, even if that is a bit less efficient engineering-wise.
I suspect that is what lies behind the recent announcement by Germany that they will phase out nuclear power by 2022. They won’t be any less reliant on nuclear power after 2022, they’ve just decided it’s politically easier to put the nuclear power plants in France or Poland than in Germany.
Which would be less efficient, and almost as dangerous in case of an accident. Brilliant.
To use electricity one must first generate it.
And with the continued grip of anti nuclear hysteria in the world, the future for electric cars (indeed the future in general) looks dark.
By the way the Green movement is international – sadly they do NOT plan for Germany to be dependent on French nuclear power stations.
Their desire to return to the cave is not limited to Germans returning to the cave.
Those interested in nuclear power should read William Tucker’s “Terrestrial Energy” (2008).
If he can make an uneducated person like me understand some of the techical issues (and he can) then he can help anyone understand them.
However, warning, Mr Tucker is a believer in man made globel warming.
Ultracaps, iirc, leak charge far faster than a battery, but that said, imho, the way forward is:
1. motor at each wheel, 150+hp to provide frictionless braking/regen
2. ultracaps to capture 1.
3. some battery capacity to store long term, but not vast.
4. an ICE as generator to free the vehicle from infrastructure (provides around 100mpg if used with 1.)
5. plug in capability
4 and 5 deals with the chicken-and-egg of electric cars: no charging points cos no cars, no car sales cos no charging points.
What we really need is someone to come up with retro-fit kits to convert existing cars.
Ultracapacitors have very good power density (say 1-10 kW/kg) but pretty poor energy density compared to petrol (say 30 Wh/kg.) They really need a two order of magnitude improvement before they’re ready for primetime. Is that doable? Who knows?
There will be problems with home charging that, while not insuperable, will be challenging. Let’s say you’ve got a 60 liter tank, such as a conventional Ford Mondeo. That’s 45 kg, roughly. That has an energy content of about 2.1 GJ at 35 MJ/l or 580 kWh (these are all ballpark.) That is the sort of capacity an ultracapacitor needs to be really competitive (but let’s assume an increase in efficiency of on-road power delivery from 25% to 90% so we can get by with 2.1 × 0.25/0.9 GJ – call it 580 MJ.) You can fill that tank in say 300 seconds. To provide that 580 MJ with electric charging in five minutes is about 2 MW out of the grid through the outlet. I don’t know what the voltage is at which power would be delivered to the ultracapacitor in practise but lets say 100V. That is 20 kA. It is very hard to shunt 20 kA around, especially with solid state. Even if you increase charging time to twenty times that (an hour and forty minutes) you’ve still got welding currents running around.
The upshot is that petrol really is astonishingly energy dense, which is why it’s such a compelling fuel.