Are electric vehicles really best option for greener driving?

January 5, 2016 by Jamie Turner And Chris Brace, The Conversation
Credit: _chrisUK/Flickr, CC BY-NC-ND

Jaguar Land Rover has become the latest car manufacturer to announce its entry into the world's first fully electric racing series – the FIA Formula E World Championship. It is reported that the racing series will serve as a platform for the development of an electric-powered road car – perhaps an SUV to rival Tesla's Model X.

As the nations of the world pledge action on climate change, the automotive industry will face renewed pressure to come up with alternative solutions. Consumer demand for passenger cars which reduce harmful emissions without sacrificing performance will be on the rise – more so in the wake of the VW scandal.

Against this backdrop, the potential of both hybrid electric vehicles (HEVs) and battery electric vehicles (BEVs) certainly needs to be considered. But they are not our only clean energy alternative.

The electric options

The internal combustion engines of both petrol and diesel-fuelled cars can be hybridised by adding electric components – such as motor-generators – together with a small amount of energy storage. Hybridisation offers an excellent opportunity to optimise the way we use the internal combustion engine. It enables the engine to operate at a higher average level of efficiency, and gives cars a way to recover the kinetic energy produced by braking, which is otherwise wasted.

It's reasonable to expect that a majority of vehicles will be hybridised to some extent in the not-so-distant future, since these small modifications can yield big returns in terms of energy use.

Straight from the grid. Credit: Birmingham News Room/Flickr, CC BY-NC-ND

The BEV is a much more challenging proposition as it requires large, expensive, resource-intensive batteries to deliver the kind of power that drivers expect. By contrast, combustion-powered cars are affordable because they are built from cheap materials using cost-effective processes and have a very inexpensive energy storage system – a liquid fuel tank. As a result, the extra costs associated with BEVs will be a major turn off for manufacturers.

What's more, BEVs only offer a marginal reduction with regard to in-use and life-cycle CO₂ emissions, compared with their combustion-powered competitors. This is because – in Europe at least – almost half of our electricity is generated by burning fossil fuels. Of course, we'll need to re-evaluate this assessment as our electrical grids become less carbon intensive. And one of the best arguments for EVs is that they help us to develop our infrastructure and technology, in anticipation of a time when becomes commonplace.

Even so, there are a number of competing technologies in the passenger car space – and it's critical that we research all possible routes to clean, sustainable transport.

Electrofuel alternatives

Electrofuels – which are fuels manufactured using renewable electricity – offer one plausible alternative to BEVs and HEVs. The idea of using hydrogen gas (H₂) made with renewable electricity to power cars has been around for a long time. The attraction is that releasing energy from H₂ produces only water as a by-product, making it a very clean fuel. But unfortunately, it presents some serious challenges around distribution and storage.

It's currently thought that H₂ will have to be stored at a very high pressure to get a reasonable amount of energy on board a vehicle – and even then, its density is only comparable to styrofoam. To be sure that H₂ storage tanks are crash- and fire-proof, they have to be extremely thick, carefully-made composite structures. For comparison: to contain the same amount of energy as a 10 US gallon liquid fuel tank, a hydrogen storage tank would have to weigh about 170kg to 180kg. This inevitably drives up costs, and that's not even considering the problem that H₂ – being the smallest molecule – has a tendency to leak out of tanks and storage systems, and can cause steels to become brittle.

Arguably, a more exciting and practical alternative is to use this technique in power plants. The H₂ generated using renewable energy can then be combined with waste CO₂, in order to synthesise methane. The methane is then injected into the national gas grid, to be used by compressed natural gas (CNG) powered cars.

The ultimate goal for this approach is to use CO₂ extracted from the atmosphere. If this can be done, the approach would yield a truly renewable fuel which takes out as much carbon from the atmosphere as it puts in. This process points the way to a sustainable future which retains the low-cost, high-utility .

Futuristic, but affordable

It is also possible to produce liquid fuels in a similar way, by using H₂ and CO₂ to synthesise methanol – an alcohol related to methane, which is the simplest liquid energy carrier. While liquid fuels take more energy to produce, they also tend to have a higher energy density than most gas fuels.

Importantly, methanol can also be blended with gasoline and ethanol, and synthesised into pure hydrocarbon fuels, which can act as substitutes for gasoline, diesel and kerosene. Creating these types of high energy density fuels will be the only practical way to decarbonise aviation, for instance. What's more, methanol can also be made into plastics and other petrochemicals, allowing many different industries to harness excess CO₂.

There's one sticking point, though: currently, the extraction of CO₂ from the atmosphere on an industrial scale remains a futuristic goal. Still, it is a known, practical process which would enable the mass use of renewable energy in some of the poorest nations on earth, while providing a supply of liquid energy to meet the world's transportation requirements. It also permits mass uptake of wind and solar power within existing economies, since fuel production provides a means of converting and storing , which the electricity grid currently lacks.

At the present time, it makes more sense to use renewable electricity in fixed applications which do not need storage batteries and to reserve fossil fuels for mobile applications, where their energy density is of most use. Because electrofuels can be blended with the we already use, they don't require us to radically change our energy infrastructure and they don't decrease utility for drivers.

Both approaches need funding, but electrofuels represent the minimum change to the status quo. They will also require no investment in infrastructure from governments, while yielding the same amount of tax revenue. For all these reasons, electrofuels seem a much more probable route to cleaner driving than BEVs.

Explore further: What if all cars were electric?

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antialias_physorg
5 / 5 (4) Jan 05, 2016
This is because – in Europe at least – almost half of our electricity is generated by burning fossil fuels.

Currently. This is a tired old argument because that is changing so fast that by the time you've finished reading the article the balance has already shifted again.

using hybrdis may sound fine on paper, but they have the drawback that they have to lug around two sets of machines. Which increases weight and increases chance of breakdown (i.e. your repair bill has no way but to go up)

The H₂ generated using renewable energy can then be combined with waste CO₂, in order to synthesise methane.

Since the idea is to get rid of waste CO2 altogether (and even go negative on that if we are to reach the envisioned climate goals) thsi is not a viable option in the medium/long run. Extractoing CO2 from sparse sources (like the atmosphere) is very energy intensive.
greenonions
4.3 / 5 (6) Jan 05, 2016
The BEV is a much more challenging proposition as it requires large, expensive, resource-intensive batteries
I don't think you could get much more bias than this statement. Building an internal combustion engine - a transmission - in parallel with a battery - and an electric motor - is not large, expensive, and resource intensive? The reason BEV's are expensive today is because the manufacturers are heisting the price - in order to cover the possible liabilities due to the new tech. The batteries for a Leaf sized vehicle are around $3,500 - http://www.autobl...-to-145/ An engine, transmission, and batteries for a hybrid has to be at least this much.

The grid energy mix is changing fast - better is fine - we don't have to shoot for perfect overnight.
ricegf2015
4.2 / 5 (5) Jan 05, 2016
A simultaneous transition to Electric Vehicles (EV) and a clean grid is the most direct and lowest risk approach to reducing atmospheric pollution to sustainable levels. EVs challenges all appear to be solvable within a decade with no further breakthroughs.

One of these is cost, driven solely by battery cost. As the "gigafactories" come on-line, EVs may over the next decade become less expensive than Internal Combustion Engine Vehicles (ICEV).

Another is range per charge. Battery energy density has been increasing almost 10% per year, eventually leading to affordable 300 mile range EVs.

Another is recharge time, which depends on recharger power. Power has increased from 25 kW to 120 kW, with over 200 kW practical within the decade.

Hydrogen is bulky and less than half as efficient at storing renewable energy compared to batteries, while producing methane from atmospheric CO2 still requires technical breakthroughs.

EVs are here now and increasingly practical.
Scottingham
5 / 5 (2) Jan 05, 2016
Methanol is no good considering how toxic it is! I had a friend who worked at a biodiesel plant, he and a few others were involved in a minor methanol spill. They were REQUIRED to stay on the job drinking tequila for the next 8-9 hours (ethanol stops methanol poisoning, really...look it up!)

I've always been intrigued by butanol. High energy density, can run in unmodified (other than fuel remap) petrol cars, and can be sourced from renewables.
gkam
2.3 / 5 (6) Jan 05, 2016
For around town, the current versions of battery EVs are great. We get about 100 miles on a charge, and charge at night. There are multiple charging spots where we live, as well for the public.

The big thing is no maintenance. No consumables, but window washer fluid. No gas, no gas stations. No oil, no smoke or smell or leaks. Quiet. Clean. And very responsive. Those of you with gas cars will be impressed with the performance.
gkam
1.7 / 5 (6) Jan 05, 2016
Drawbacks to pure EVs:
Everything runs on the battery, which means the heater can suck much power from it. But my car figures out the mileage left by assuming the same load, and if you shutoff something, the projected range goes up.

They are expensive, and not because ICE are cheaper, but for the price of the battery and to be cautious with new technology and its consequences.

Those of you with ego problems will not like the lack of the exhaust noise.
david_king
not rated yet Jan 05, 2016
What about agricultural ammonia as a carbon free fuel? It's relatively easy to convert an ICE to run on the stuff and keeping it liquid in a tank is no problem at modest pressure. We already have large transmission pipelines across the midwest that could use local wind and solar to store and deliver that energy hundreds of miles away for a fraction of the cost of expanding the electrical grid.
Renewable production of NH3 is the key and apparently we are quite close to achieving that:
http://phys.org/n...ion.html
ricegf2015
1 / 5 (1) Jan 05, 2016
@david_king Isn't the smell a bit of an issue with ammonia? Would a leak in a closed garage over several days potentially build up enough ammonia vapor to cause health impacts, given that it is both caustic and hazardous?
Eikka
3 / 5 (2) Jan 05, 2016
using hybrdis may sound fine on paper, but they have the drawback that they have to lug around two sets of machines. Which increases weight and increases chance of breakdown (i.e. your repair bill has no way but to go up)


That depends on how you implement a hybrid engine.

Some engines integrate the starter motor with the flywheel, which reduces parts count and mechanical complexity, increases reliability, and enables hybrid operation.

Others such as Toyota's hybrids actually integrate the electric motor into the operation of the differential CV transmission, which again actually reduces complexity and parts count compared to a regular automatic/robotic gearbox.

Yet others simply put an electric motor on the rear wheels and a regular engine at the front, but that too is far simpler and more reliable than regular 4WD.

So I don't quite buy the argument about repair bills simply due to the car being a hybrid. The real concern is again the battery system.
david_king
5 / 5 (1) Jan 05, 2016
@ricegf2015
Ammonia is easily detectable at very low concentrations by your average homeowner. Given that it will be compressed at around 100PSI one would like to think that any and all leaks could be eliminated as they are in gasoline powered engines for the same reasons. Ammonia becomes toxic at concentrations above 300PPM but no one would want to be in the room at that level.
animah
5 / 5 (2) Jan 05, 2016
Those of you with ego problems will not like the lack of the exhaust noise

How do you find the noise situation with your car? Do you have to be extra careful to avoid "sneaking up" to people who can't hear you? I'd be a little worried with the kids in the driveway all the time...
david_king
5 / 5 (3) Jan 05, 2016
I was nearly run down several times in France by big electric motorcycles that are virtually silent. We've been living with bicycles for quite a few generations now so we'll undoubtedly adapt to the new danger.
Eikka
3 / 5 (2) Jan 05, 2016
Since the idea is to get rid of waste CO2 altogether (and even go negative on that if we are to reach the envisioned climate goals) thsi is not a viable option in the medium/long run. Extractoing CO2 from sparse sources (like the atmosphere) is very energy intensive.


Biomethane production and biomass combustion is a very good source of concentrated CO2. You also have other CO2 sources such as cement production and waste incineration, that are simply vented into the air because nobody needs it. There's plenty of CO2 available for making automotive fuels.

And athmospheric extraction isn't -that- energy intensive even with today's technologies. It's just really expensive.
greenonions
3 / 5 (2) Jan 05, 2016
Eikka
Yet others simply put an electric motor on the rear wheels and a regular engine at the front, but that too is far simpler and more reliable than regular 4WD.


I bet you don't have a source for saying that putting an electric motor - a battery - a charging device - an electronic control box - that all has to run in parallel with the i.c.e. - is 'far simpler' than an extra drive shaft and differential unit on a 4WD. You really don't have a clue do you?
gkam
2.3 / 5 (6) Jan 09, 2016
"How do you find the noise situation with your car? Do you have to be extra careful to avoid "sneaking up" to people who can't hear you? I'd be a little worried with the kids in the driveway all the time..."
-----------------------------------

The car has backup camera and capacitive sensors & alarms at every corner, excellent visibility, and warnings about being a careless driver.

Tire noise in sufficient, usually, to tell when the car is coming. Still, those of us used to noisy vehicles will have to be careful and adjust. It was a point from the very early days of electrics, too.
greenonions
4 / 5 (4) Jan 09, 2016
How do you find the noise situation with your car?
The Nissan Leaf has an alarm that sounds when it is reversing. It also has a backup camera that gives you great visibility - really helps when pulling out of parking spots - as you can see down the row of cars much better - with the camera on the rear door. Going forwards - the Leaf has an audible signal that sounds when you are going less than 18 mph. If there are kids in the driveway - I would be much more comfortable backing up with a Leaf - Audible alert, and wide range camera mounted low on the back door - than backing up in a gas car.
gkam
1 / 5 (4) Jan 09, 2016
If one fails to notice anybody or anything behind or too near them in the wide-view camera, the capacitive sensors emit beeps which change in tone and frequency as things get near. At the same time, the screen flashes yellow and red lines showing where the sensed object is.

Beats the heck out of backing up without them.
TheGhostofOtto1923
3.4 / 5 (5) Jan 09, 2016
capacitive sensors
Wow I bet HE knows what he is talking about.

You retard.
Uncle Ira
5 / 5 (3) Jan 09, 2016
capacitive sensors
Wow I bet HE knows what he is talking about.

You retard.


Actually I think when he was trying to look up a real e-car to tell us all about he got in a hurry with his researching (shocking with him, eh) and got confused on the capacitive TOUCHSCREEN sensor for the driver's control screen.

But then I might be wrong. He IS the former Robotic Engineer and the former Electronics Engineer. It might just be that the VW peoples are lying about it and really did put them on the cars without wanting anybody to know they are on there. They didn't want to look like they were bragging or anything
david_king
5 / 5 (1) Jan 10, 2016
A capacitative sensor would warn you once you've hit the target and knocked them down -in case you should want to finish the job properly.

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