Thursday 24 November 2011

Recharging electric cars

They showed a "new" episode of Top Gear yesterday, which presumably means it's only the third repeat, in which they road tested some electric cars. They said that the cars are actually quite OK to drive, but their range is less than 100 miles and then you have to plug them in to recharge the battery, which takes about 12 hours.

It strikes me that the manufacturers could get round this problem by having their own "filling stations" dotted around the country, where they hire out their own pre-charged batteries. So you turn up, whip out your flat battery and exchange it for a charged one and pay your £10 or however much they want to charge to be competitive with petrol, which can't be too difficult, as there's no petrol duty on electricity.* A bit like with the Calor Gas bottles. And just about any shop could be a "filling station", all it needs is a spare plug or three.

* If there were a duty like petrol duty on electricity used to charge car batteries, we'd probably find that electric cars are woefully uneconomic to run as well as being very expensive to buy. Neither are they "zero-emission" in the first place, unless they are only charged with nuclear or wind generated electricity. But these are secondary issues.
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UPDATE: Richard in the comments points out that the Israelis are already doing this, the whole process takes two or three minutes:

29 comments:

Robin Smith said...

Yes this has been touted for quite a while. Particularly by Moonbat.

Zero emissions from the tailpipe!

Desert solar power and nuclear. Forget wind.

Range in the one I tested for TRL last year was 50 miles.

Current models are highly sub optimal in design and weight. It would quickly get better.

Driving them is a dream. Smooth and faster accelerating.

See here for trial results

http://gco2e.blogspot.com/2010/08/electric-car-end-of-trial-results.html

Ken Reay said...

I have not driven one of these cars, so, I may be wrong, but my belief is the batteries are of significant size, and changing them is not a two minute job.

Mark Wadsworth said...

RS, good stuff.

Ken, no, it's a 12 hour job, so the "filling station" needs to anticipate daily demand and then add on a few spare batteries, which he recharges overnight to meet demand the next day.

Keeping track of all these batteries can't be any more difficult that the computer systems for the Lottery, i.e. you could have an iPhone app telling you where the nearest filling station is and how many spares they have at any one time, which you can book in advance and so on.

A battery costs £7,000 and lasts for five to ten years, so that's £1,000 a year amortisation, if it's reused once a day, the fee for renting it would be cost of elcetricity (£10?) plus £3 amortisation on top, plus a profit margin, call it £15 (=15p per mile assuming 100 miles between charges), it might work out at much the same as running a petrol car, I don't know.

Barman said...

I can see how batteries could be designed to be easily replaced at a 'filling station' and even a 'standard' produced so that your filling station didn't have to be manufacturer specific (like gas bottles)...

But what if you got a battery that had been thrashed around Tesco's car park the day before by some spotty 17 y/o in a Corsa and let you down ten minutes up the road...?

Lola said...

The whole 'drive up and replace the battery' thing has already been thought of.

What about fuel cells? Honda have a prototype and it works well, plus the 'exhaust' is H2O.

Personally I reckon some form of hybrid with a petrol/diesel + electic is most likely.

The next way to save energy in cars is to reduce the weight of the bloody things. Cars are far too fat. Get the weight down by 50% and fuel economy will improve as it takes most energy to accelerate. Keeping them moving at 70 ish just takes whiff of throttle on a level road. If you also made them more aerodynamic that would help as well.

Anyway as Clarkson and Co pointed out a small high speed diesel can do much the same cost per fuel mile as current (pun intended) electric cars.

Mark Wadsworth said...

B, re the thrashing, I didn't know that Corsa did electric cars, and I don't think you can 'thrash' them anyway.

I'm sure it's not beyond the wit of mankind to run a few tests on the battery before it's recharged and afterwards to make sure it's charged properly (you weigh it to see if enough electrons have been added, or something).

And it's not your battery, so the exact condition is not so important, the risk of 'thrashing' stays with the filling station or the manufacturer who has to accept that some batteries will only last a year or two.

Mark Wadsworth said...

L, I don't know about fuel cells. As I explained, the full cost of electric/batteries is about 15p a mile once you take depreciation into account, and that's without fuel duty.

Barman said...

And it's not your battery, so the exact condition is not so important, the risk of 'thrashing' stays with the filling station or the manufacturer who has to accept that some batteries will only last a year or two.

Unless you are on a day out with the family and get stranded because the battery is knackered...

What about fuel cells? Honda have a prototype and it works well, plus the 'exhaust' is H2O.

The problem with fuel cells is that there is no 'natural' source of Hydrogen... so you have to manufacture it using vast amounts of electricity.

Mark Wadsworth said...

B, you're not making a fair comparison. We know that petrol cars work well, there's a network of filling stations across the world selling standardised petrol etc.

But what were things like a hundred years ago? This all took time to build up. Compared with petrol cars a hundred years ago, electric cars today look like cutting edge reliable technology.

Barman said...

MW True. But...

The beauty of the petrol vehicle is that you own all of the parts. You know that the performance and reliability are dependent on your looking after it and servicing it regularly.

With a 'shared battery' vehicle you are reliant on other people looking after the key element of your car. As you said, batteries have a limited life and and you have no way of knowing that the battery you've popped-in for your family holiday to the coast isn't at (or beyond) its specified life... Or that some spotty yoof hasn't done the equivalent of 'thrashing' it in some way.

Like gas bottles... I live in Cyprus and all of our gas is delivered in bottles. You buy the first one and then pay for a refill.. Sometimes the refill will be okay - as good as new - but often the refill is battered and beaten and the seals might leak too...

People don't look after things that they don't own....

James Higham said...

changing them is not a two minute job

This may be so but they can be made easily changeable by design. Some sort of forklift thingy takes out and puts in. It's not a major issue.

Mark Wadsworth said...

B, it's your choice. Patiently recharge your own battery for 12 hours or swap it for a full one and get back on the road.

Barman said...

B, it's your choice. Patiently recharge your own battery for 12 hours or swap it for a full one and get back on the road.

Or stick to what works now and not what the eco-loons want you to have...

This drive (snigger) for electric cars is ridiculous when government policy will almost certainly see us running out of electricity for our current needs - let alone replacing millions of barrels of oil with electricity...

I'm sure one day we'll look back on the internal combustion engine in the same way as we do with steam cars and horse drawn vehicles. BUT those things were replaced by the ICE because it was better and cheaper - NOT because eco-loons wanted to save the planet.

Mark Wadsworth said...

B, sure, the idea of encouraging people to drive electric cars while gradually shutting down UK electricity generation* is madness. I like petrol cars! I'm just saying that the 12-hour battery charge issue is not insurmountable.

* Basically, EDF nuclear chaps have persuaded the EU that they have to introduce reg's saying that UK coal fireds are too 'dirty' and have to be shut down, so that hey presto EDF can come along and build us some no doubt overpriced nukes etc.

Barman said...

Indeed... energy policy is madness... We should be shovelling coal from the ground as fast as we can... and getting into shale gas.

I'm sure that the 12-hour charge issue is not insurmountable... I'm just very against electric cars per se... I'm sure their time will come when we have sorted all of the issues (including power generation) out...

Anonymous said...

I think the 50km-electric-the-rest-on-whatever hybrid (PHEV50) could be a winner in the near future. Most people drive under a certain length on average each day but want to be able to drive longer trips now and then, so most trips could be electric. People'd connect their cars to price-sensitive chargers and choose to drive on gas or electricity based on price/km.

Interesting historical take in the whole EV business:
http://www.lowtechmagazine.com/2010/05/the-status-quo-of-electric-cars-better-batteries-same-range.html

-Kj

Tim Almond said...

One benefit of electric cars is that central generation of power is more efficient than lots of little engines being fired up for a few miles at a time.

Right now, though, the big reason that people buy cars like the g-whiz is that you avoid the congestion charge (which is absurd as you're still creating congestion). You'll get the money back over a couple of years.

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Lola said...

Barman, I know. I know. Getting the hydrogen is the tricky bit, but of you have lots of nuclear power stations....

Bayard said...

What gets me about electric cars and hybrids too, is that they should be being sold for performance, not to save the planet. The electric motor will always outperform an IC engine as the torque is constant throughout the rev range. Why do you think the railways went straight from steam to electric (or diesel electric)? What's more, with electic power you can have regenerative braking, which extends your battery life (or puts down your fuel consumption, if you are driving a hybrid).

Anonymous said...

JT: lots of charging vehicles could also make central generation even more efficient if done mostly duringn off-peak, levelling demand.

Anonymous said...

What's more, with electic power you can have regenerative braking, which extends your battery life (or puts down your fuel consumption, if you are driving a hybrid).

That's why we should have electric drivetrains even on vehicles that'd mostly just run of gas, you'd have gas (or any type) engines just running as generators going on maximum efficiency and have a battery or capacitator acting as a buffer and harvesting regenerative energy.

-Kj

Richard said...

Swappable battery stations are already happening in Israel. Good video here of the whole process that takes less than 3 minutes.

http://marginalrevolution.com/marginalrevolution/2011/06/electric-cars-in-israel.html

Anonymous said...

The automotive industry seems to have coalesced around the idea of plug-in hybrids as the next step. (That's a hybrid where you can also charge the battery from the mains.) No worries about novel recharging infrastructure there! Recharge overnight for the commute, but otherwise treat as a normal car.

The Vauxhall Ampera / Chevrolet Volt, for example, is about to be launched in the UK. (It is already available in the US, and General Motors have sold over 5,000 of them.) Wikipedia reckons it will cost £33,995 in the UK (minus a £5,000 government subsidy).

Bayard said...

Kj - Yes, and it's not as if the series-hybrid technology hasn't been around since the '50s. Another point seldom mentioned is that IC engines are more efficient if they run constantly at the speed of their maximum torque, which again, series-hybrid allows. The Vauxhall Ampera is along the right lines, but it still has a petrol, rather than a diesel engine.

Anonymous said...

I think the 50km-electric-the-rest-on-whatever hybrid (PHEV50) could be a winner in the near future. Most people drive under a certain length on average each day but want to be able to drive longer trips now and then, so most power could be electric. People'd connect their cars to price-sensitive chargers and choose to drive on gas or electricity based on price/km.

Robin Smith said...

MW From my stats

http://gco2e.blogspot.com/2010/08/electric-car-end-of-trial-results.html

A 12 hour charge was about 10kWh, so £1.50 tops. Or £0.03/km for the juice.

Emissions were about 110 gCO2/km so about the same as the best fossil powered motor.

Batteries already have built in micro processors that guard against abuse. This will only get better.

Garage stocking will be a piece of cake. The more its done the easier to predict stock. I used to traffic engineer international telecomms networks. Its done.

Lola - fuel cells I love to death. Hydrogen fuel could be mined from desert solar. The issues with H2 is storage. Not impossible, but... Google it. And "quite" on weight, I did mention this above

The real issue today is RANGE. 50 miles is not far enough unless we have "battery stations". Empirical and primary evidence from yours truly.

Lola said...

Bayard. Don't steam engines have the same flat torque curve as electric motors?

Bayard said...

They do. That's why the old steam cars had such great performance (for their day) and why the railways went straight from steam to electric (and why steam traction engines are banned from tractor-pulling contests!)