6 comments so far.The pros and cons of electric cars – Readers Letter
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I would like to make a few points here with regard to electric cars which have been in the news recently. First of all I’m not writing this in order to put down the idea of electric cars, I’m just trying to be realistic. We keep forgetting that the electric car is not a new concept as the first one was built in the mid 1830’s. So they have had around 170 years to get it sorted and so far they haven’t come close to the efficiency of a petrol car.
Lets just compare the two for a moment. If we take an average tank containing say 40 litres of fuel it will have a weight of around 40kg, 30kg for the fuel and around 10kg for the tank. One litre of petrol contains around 9.5 KWh of effective energy. Unfortunately the petrol engine is not the most efficient beast in the world and only returns around 30 to 35%, so at the wheels we have around 3250 Wh of effective mechanical power per kg of fuel. Gross energy contents of a fully charged, new battery varies from about 40Wh/kg for lead acid, to about 200Wh/kg for lithium. Even considering the greater motor efficiency of around 80%, this means that at the wheels we get from 32 to 160Wh/kg. That’s 20 to 100 times worse than petrol.
I agree with the points being made about Malta’s traffic pollution problem and how the electric car would certainly reduce that but only at ground level. We still have the problem of how the electricity we are putting into the car is generated. If we are using heavy fuel oil then we are simply shifting the pollution problem from our back yard to someone else’s. Coal gas and uranium are no better as they are all from non-renewable sources. We can consider hydroelectricity as renewable but that’s not an option in Malta. Tidal, wind and solar are all available but unfortunately use a lot of fossil fuels in their manufacture and in some cases cost more to produce than they will ever generate.
Oil prices will continue to rise but we will continue to pay for it. When I began driving I can remember putting £1 of petrol into my car on a Monday and it took me back and forth to work until Thursday. Don’t we all wish those days were back? Fossil fuels will end up running out at the present rate but when that happens we will shift over to synthetic fuel made from vegetable oils or alcohol. Again this is not a new idea as the Germans were using such fuels in the 1920’s.
The main problem with present day cars is that they are too heavy. We only have to look at Formula One racing to see that it is possible to build cars lighter and stronger so instead of having a big heavy car we can have a small light car with a smaller more efficient petrol engine doing the same job. To sum up I would love to be able to buy a small electric car for the same price as a petrol car with the same range and the same efficiency and a promise that it would always be charged from sustainable resources and a battery pack that wouldn’t need renewing. Unfortunately I’m not holding my breath.
James A. Tyrrell,
N. Ireland.
Hello James,
too start with,Happy New Year to you.
About that light weight car,im not sure,because sometimes when I drive around
at Gozo,with all the bad roads,I would not feel save in a light weight car,
Insted I would prefer an Army tank.(joke)
Sorry James for not being serious about this,most of the time I am verry pleased
with you keeping up the latest news.
I am verry curious about the trees at the square in Victoria,will they still stand there the next
time we are vissiting It Tokk??????
Please keep up with us,and thanks for all your investigations and energy
you are spending on Gozo,
all the best from Holland,Annet.
Hi Annet,
And a very Happy New Year to you and yours. I’ve actually been in a tank Annet and the suspension is not best suited to the Maltese potholes. I think they have been there since World War 2 and were put in place just in case the enemy managed an invasion! Another thorn in the paw of electric cars in Malta, which I forgot to mention, is of course the power supply industry. The three words, which appear most in the local press, are ‘scheduled power suspensions’ and I really don’t think the power stations could take the extra load.
As far as the trees are concerned I would like to think that they will still be there but knowing how things are done in that part of the world someone could accidentally cut them down overnight. Of course no one would be responsible and it would probably be blamed on a rogue sub contractor. Obviously it would take a few days for the blame game to begin, as we would have to wait for the Gozo Ministry to read about their disappearance in a paper over breakfast.
On a more serious note Annet let us hope that 2011 is the year that Eco-Gozo at least reaches the stage of conception at long last. And I hope that when I return the beautiful old ficus trees are still there. I mean could you imagine the square without those trees?
I think your analysis of comparing efficiency based solely on weight does not paint the entire picture. You could have just as easily made the comparison based on energy per bolts used for the construction of the car. A better comparison might be cost per mile, total cost of total mile over the life of the car or units of total pollution per mile.
@JH. As you say there are numerous ways of making comparisons between petrol cars and electric cars but the one I used is based on well-known and available figures. At the end of the day weight is after all the main factor. Take for example a new 5-door Ford Fiesta manual. The total weight of the car is 2537 Lbs. If you take a driver and three passengers each weighing 12 stone you have a total cargo weight of 672 Lbs. So in effect it takes 4 times the weight of the cargo to carry them. My point about weight is that we have the technology to make cars a lot lighter without losing any of their strength and therefore make them more efficient.
People talk about how good battery powered cars are but don’t actually get down to the basics of their operating costs. For example probably the best-known electric car is the Tesla, which I’m sure everyone will agree, is a fantastic car. But it uses 6,871 lithium ion cell batteries the life expectancy of which is 4 to 5 years. Replacement cost of the batteries at wholesale price in is roughly £14000, which produces a yearly cost of about £3500 plus the cost of charging. You also have to remember that by the fourth year the electric car will have lost 20% of its efficiency anyway.
So if we are driving say 12,000 miles a year in a Ford Fiesta returning 40 MPG at about £5 per gallon the yearly cost will be in the region of £1500. As I said I’m not knocking electric cars but we have to be realistic and as things stand the normal working person can’t afford the initial outlay for the electric car let alone the running costs over its lifetime.
Happy new year Mr Tyrrell
As usual you write letters that makes people think twice because the arguments that you raise are very informative and enjoyable to read
As an owner of a electric car hoping to do my bit for the environment and being told that they would do 98 miles per charge after owning it for 3 weeks and finding that it only averaged 50 to 58 miles per charge that would not get me to the shops and back, then contacting the makers and being told that it was because we lived in a hilly area i have reverted back to my diesel car which does 68 miles to the gallon and have traded the completely useless electric car back in so showing that weight does not make a lot of difference to an electric car