/ Motoring

Are you re-volted by the plug-in trend?

Petrol pump facing electric car wire

One big trend that emerged at the Frankfurt Motor Show earlier this week is the popularity of hybrid technology. Everyone from Peugeot to Porsche was showing off at least one new model…

In fact, most of the gorgeously exotic sports cars at the show had hybrid technology – Porsche 918 is a plug-in as is BMW’s stunning i8. And the other star of the BMW hall – and the taxi stand running journalists around the show on press days – was the i3 supermini that’ll be offered in electric and range–extender hybrid form.

But it’s not only supercar and luxury car brands that are embracing this technology – VW slammed its cards on the table declaring an ambition to become the leader in hybrid and electric cars by 2018. To kick start this it had electric versions of the Golf hatchback and Up city car on its stand.

Sparks fly for electric cars

And Peugeot is following the lead of Renault with its 208 FE plug-in hybrid concept. I guess it should come as no surprise that Vauxhall has this week lopped £3,500 off the price of its Ampera range–extender hybrid. The starting price is still £28,750 (after government grant), but at least this brings it closer to the asking prices of conventional rivals.

And will this clever new technology be the panacea to motoring costs that it promises? If the hybrid daddy, the Toyota Prius, is anything to go by, the answer has to be yes. Although the plug-in version of this got nowhere near the official claimed 134.5mpg, the 78.5mpg it achieved in our tests, is one of the best figures we’ve ever recorded.

But such impressive fuel consumption figures will only be achieved by city drivers and those prepared to sit in the slow lane on the motorway (the Prius’s consumption rose to 48.7mpg on the motorway), so the plug-in isn’t the ideal choice for everyone. And plenty of small, eco-focussed diesel superminis are now achieving almost as good mpg. VW’s 1.2 TDi BlueMotion, for example, did 74.3mpg overall and 61.4mpg on the motorway.

So are you ready to jump on the hybrid bandwagon? Or are you going to stick with conventional car power?


Until the arrival of catalytic converters, diesel particulate filters and low sulphur fuels, electric vehicles offered useful environmental benefits for driving in town centres. I am not convinced that they are much better compared with conventional modern engines.

The best opportunity for electric vehicles is for urban use, where high speed and acceleration is unnecessary. That will place much less demands on battery power, the Achilles heel of all electric vehicles. Manufacturers may be able to turn out electric vehicles that can accelerate from 0-60 mph in under 10 seconds, but I think they should be focusing on the market for delivery vehicles and small cars for urban use.

Remember where the fuel comes from for your electric vehicle – gas-fired power stations for example. And how would our generating capacity cope with a large increase in electric-vehicle demand?
Higher efficiency petrol and diesel with electric back up, using regenerative braking for example, can improve efficiency and still give normal range.
One way to be energy efficient is to simply use less by not driving as much. Improving public transport could help here.

There is the opportunity to use locally generated power (e.g. from solar panels on the garage roof) and energy from the grid when there is surplus capacity. That should work well for hybrid vehicles, where it is not a disaster if the batteries are not fully charged at the start of a journey.

That electric cars will often just shift the pollution elsewhere has already been touched upon, although a modern generating plant will burn the fossil fuel more efficiently what hasn’t been considered is where all this extra electricity is going to come from. We’re already facing a generating capacity shortfall thanks to the EU’s insistence that we close many of our large coal burning power stations. A switch to electric cars could be the last thing we need.

We produce our own electricity through solar PV and house heated by sustainable wood. We need to tackle climate change now – that means cutting back on fossil fuels straight away – using cars less etc. We are shifting from dirty petrol to electric. If you care about your grandchildren it makes perfect sense.

I’m confused about the fuel consumption figures given for plug-in hybrids. For example, you said in your tests the plug-in Prius achieved 78.5 mpg. Was that test starting with a fully charged battery and ending with a fully discharged one? What figure would you get if you started the test with a discharged battery, and wouldn’t that be a fairer comparison to conventional engines?

I hope you are not expecting fair comparisons, Clint. Since when did marketing people do that? 🙁

Is Clint referring to tests done by Which? I hope we don’t classify them as “marketing people” (of whom, it is said, it’s the 95% who give the other 5% a bad name).

I was referring primarily to the figures obtained in actual road tests by Which? as they generally seem to be more realistic. The Government figures of 133+ mph sound a bit far-fetched, but even then I would expect these to adhere to official standards intended to make comparisons fair (notwithstanding the previously stated tactics of manufacturers). So my question is, when these tests are made (both Which? and Government ones) does the measured consumption take account of the energy supplied by the battery and the gas used at the power station to produce that?

Er, I meant “133+ mpg” of course, not mph. Also, thinking about what I just said, the mpg figure obviously doesn’t include gas used at the power station to produce electricity, because gas is not measured in gallons. So, my ultimate question is what is the mpg when the batteries are totally flat? That’s what I would consider a fair comparison to petrol cars. Imagine you are on a long journey, say from Land’s End to John O’Groats and back again, and there is nowhere to plug in your car on the way. What overall consumption would you get?


I expect that the small print will explain that drivers of these hybrid vehicles may achieve different fuel consumption depending on their driving style, environmental conditions, traffic on the road and if they drive long distances. 🙁

You are right, of course, and the answer is that these cars make more sense for shorter journeys.

Like myself people are realising that there is a synergy between having solar panels and using the excess generation to charge an electric vehicle. Petrol or diesel has to be extracted from the ground the same as gas then further processed to be a suitable fuel which is an energy intensive operation.
At the moment without trying too hard my running costs are 4p per mile , with larger solar systems this could dramatically decrease . Also vehicle to grid systems are being developed to use the electric vehicle battery as a grid storage device , this helps to de-centralise the electric grid requiring less generation by large fossil fuelled power stations.

I wonder how the economics would stack up for using solar panels to charge your car. An investment of up to £10k might be needed, with the marginal unit cost difference now between feed in tariff and supplied electricity, does it make any financial sense? Better perhaps to charge overnight on Economy 7 or other off-peak tariff?

I agree, Malcolm, but financial sense does not always govern our choices when buying and running cars. Many buy new cars despite the well-known fact that their cost of motoring would be a lot less if they bought a similar car that was a year old. Many buy expensive cars, despite the fact that depreciation, fuel and servicing may cost significantly more than for a cheaper model.

I remain unconvinced that an electric car is of significant environmental benefit, but if I did then paying for solar panels might make more sense than buying a luxury model.

We can get too obsessed with “value for money”, can’t we. We do buy goods and entertainment for other, emotional, reasons that are just as valid as whether it is a “sensible” purchase. Clothes is perhaps a good example – how many pairs of trousers do you need? Don’t check my wardrobe.

That is my point. For anyone buying an electric car on the basis of the environmental benefits, generating the electricity to power it makes sense.

I’m not all that convinced about the environmental benefits of solar panels. Although I have not had an involvement in this area for some time, I remember that, at that time, the energy needed to produce a photovoltaic cell was greater than the energy it produced in its lifetime. No doubt improvements to the production methods have been made in the meantime but I suspect it’s still a pretty close run thing. The only reason that solar panels make economic sense at the moment is the level of subsidies being paid. The main environmental benefit from solar panels is that all the pollutants are being generated a long way away by the Chinese coal fired power stations.

As a side issue, really relating to another conversation, the ‘International’ ‘phone calls received here used to relate to accident and PPI claims. Now they are all trying to sell me solar panels!

I think it’s great that car manufacturers are developing alternatives to the good old internal combustion engine. However they are a very long way from coming up with something viable so despite my support it’s very unlikely I’ll ever be driving one.
They need to work much more on range, vehicle cost and maintenance cost such that these are brought inline with existing petrol and diesel offerings. Only then will they start selling them in any serious numbers.
Some years yet, but I’m sure they’ll eventually get there.

Gerard Phelan says:
27 September 2013

Pre-1910 motor cars were a world apart from those available in the 1930’s, but had people avoided them because they were slow, open to the elements and expensive, just as people now decry plug in electric/hybrid cars, then there would have been no incentive for the young car companies to do better. They will improve and are getting rapidly better.

Rather the same applies to solar panels. The solar conversion efficiency of about 20% is improving and there is obviously much room for improvement. (The Fraunhofer Institute for Solar Energy demonstrated 44% efficient panels in 2013, but only in a special test environment). The cost of manufacture is reducing. Coal and Gas power generation is not a very efficient use of the energy those fuels contain. UK Govt figures suggest an average efficiency of 35% of which 2% is the loss in transmission to the end user. Thus when replacing remotely generated electricity by local supplies, we are saving not only correspondingly more coal and gas but deferring maybe forever the need to increase power generation capacity and the building of new transmission lines.

In the early days of electricity supply there were many small scale local suppliers, just as you propose. The reason that the national grid system came into being is that of security of supply – if the local supply system failed then the gap could be filled in from the grid. The problem of supply security is still relevant whatever the means of local generation.

The problem with both solar and wind generation systems is that they do not necessarily provide power when it is actually needed so some form of storage is required. For small scale domestic applications this can be achieved with batteries but as the scale of generation is scaled up these become a very poor option. There are more sensible ways of storing the energy but these only make sense if the scale is large enough, which gets us back to the need for a national grid system!

I feel that the only sensible long term solution for automotive applications, amongst others, is to move to the use of hydrogen. The technology to use hydrogen already exists but the problems to be overcome are economic production, means of distribution and storage. The last of these is of particular importance in the automotive application. Petrol and diesel are very efficient in terms of the energy stored per unit volume. Batteries are very, very poor in this respect and, unless someone comes up with some new, revolutionary technology in this area, this situation will remain. Energy storage efficiency for hydrogen is not currently as good as for petrol/diesel but there are encouraging lines of research in this area. Production and distribution, though, still needs some work.

I can’t help but feel that battery-based electric cars are a dead end rather than a long term solution.

My concern with hydrogen is its explosive potential if there is a leak or a major impact. Presumably hydrogen would be produced at off-peak times – a good way of levelling electricity demand, but it will still require largely fossil fuel to produce it – is it that energy efficient?

The thought of using hydrogen as a fuel worries me too. In the 70s or early 80s it was suggested that the solution was to adsorb hydrogen onto palladium, but I guess this was too expensive to be practical.

I’m not too keen on the idea of large lithium batteries in cars. Quite apart from the amount of energy stored, lithium is a highly reactive metal that could cause problems in the event of an accident. At least it now seems unlikely that we will see sodium-sulphur batteries (using molten sodium) in cars.

I agree that the explosive potential of hydrogen is likely to be a problem, but then petrol, in vapour form, is not exactly inert! Cost effective in-car storage with good energy density approaching that of fossil fuels is one of the problems that needs to be solved. There are some encouraging lines of research taking place in this area and there does seem to be a willingness to come up with a solution.

Production of hydrogen is certainly an energy intensive process and using fossil fuels for this purpose does rather negate the advantages. However, it could be an effective solution to the problem of sporadic generation from such sources as wind power – perhaps hydrogen generation could make best use the off-shore wind farms.

It is certainly worth finding effective solutions to the problems relating to hydrogen as a fuel for automotive applications because I can’t see any other form of energy storage that comes anywhere near current petrol/diesel systems in terms of energy density.

Wavechange commented:

“I’m not too keen on the idea of large lithium batteries in cars”

You might be interested in this –


I suspect that ‘not too keen’ could well be understating the situation!

Jim Kenney says:
9 October 2013

This is a great thread; electric cars, hydrogen and renewable energy – it would have been the stuff of sci-fi a few short years ago. Clearly they all have a part to play; electric cars keep the pollution away from urban areas, hydrogen can be used to run a converted conventional petrol car or perhaps the buses on trial in London. And they are all forms of energy storage which is the panacea of smart grids, renewables and even smoky old coal/gas turbines that are crying out for energy storage to smooth out the peaks and troughs of demand. Great stuff! Bring it on

An electric car is a joke where I live in southwestern Montana. The distances we sometimes travel are far beyond the range of electric cars. I guess they would be fine to and from work, but that about it. You are then looking at licensing and insuring another vehicle. For me a trip to another larger city is over 100 miles one way. Let the people in cities buy them. Useless where I live.

I’ve run a Toyota Prius plug in for 18 months and covered 9000 miles. Most of this driving is in Cambridge but with longer trips as well. My average consumption has been 120miles per gallon, so not far off the Toyota claimed figure. I plug it in every time I come home so it is always fully charged. Totally reliable.

However, I’ve decided to sell the car because I find the forward visibility and blindspots, caused by very thick A and B pillars, is dangerous in a city with so many cyclists, who seem to be travelling faster and faster. Yes, the rear visibility is also dreadful and the 2016 Prius hasn’t improved this at all.