Wednesday, 15 December 2010

Electric cars

This post has been generated by three cross currents of thought. The first was seeing one of those conspiracy theory 'Documentaries' about how wicked 'Big Oil' killed off some whizzy super electric vehicle supposed to replace all those pollution spewing Internal Combustion Engine propelled cars and trucks. The second was a piece in the Tellytubbygraph about subsidies for Electric cars. The third was a conversation I had about practical technologies with a work buddy.

Now electrically powered cars have been around a long time. Over 100 (One hundred) years. The technology is relatively simple. Electro Magnetic Force (Electricity, or plain old 'leccy' as the transfer of electrons along a conductor is known) translated into rotary motion by magnetism acting on coils and windings. Yes I know that's an over simplification, but this is a blog, not an encyclopaedia, for goodness sake.

Electric motors work. So long as there is sufficient electricity, they work very well indeed, and quite efficiently. Ideal for driving a vehicle you might think. Well, yes and no. The thing is, that while electric motors are a relatively efficient means of converting power into motion, independent electrical storage media (a.k.a. batteries) have not attained this level of utility. The major issue is recharge, and the time it takes to recharge the storage media without it blowing up.

Batteries are in their simplest terms Electro-chemical devices used to store and release electrical energy. They do this by a chemical reaction which releases electrons from atoms, which in their turn barge into the electron shells of other conductor atoms, thus creating a 'flow' of electricity. Again, this is an over simplification of the process, but my previous point about this being a very generalist blog still applies. It may surprise my reader that power storage devices of this nature have altered little over the past couple of thousand years. Two differing conductors and an electrolyte are all that is required. Modern batteries have come a long way from the old Lead / Acid contraptions of the late 19th and early 20th centuries. but they still rely on the same principle. Charging too fast will overstimulate the chemical reaction within the battery and make it overheat, and even explode. So recharge times must be adhered to, lest you end up with a recharge station full of toxic chemical sludge and fast moving shards of metal and plastic. Short of some form of fast electrolyte recharge, where the old fluid is pumped out and replaced with fresh (Which doesn't replace / repair corroded anodes and cathodes incidentally), there is the major issue with electric cars. Not function, but recharge and recharge system longevity.

Perhaps some other process which 'refreshes' the electrolyte and shifts those pesky ions (Charged particles) to the correct end of the battery might be an idea. Whether such a process could be made to work or not would be down to whomsoever could crack the chemistry. Then you've opened the environmental can of worms about what you do with tonnes of exhausted battery electrolyte, which would be a by product of all those chemical recharges.

Until the electrical storage issues I have outlined above are resolved, the truly practical Electric Car will remain an expensive short range vanity item not worth spit in cold weather. As far as I'm concerned, the five thousand pound subsidies are worthless because the batteries need to be replaced for around $9000 (about six thousand quid) a pop after five years (or even less). God alone knows what the resale value of such vehicles might plummet to.

There's also a big question mark over how much pollution these things are responsible for. As far as I can see they simply defer, rather than produce no emissions. Power will still need to be generated to drive the things, and that will require a more robust energy grid, should the recharging business ever be solved. Then there is the pollution from Rare Earth production that goes into making modern batteries. Maybe that was why GM etc crushed all those leased EV1's, because the cost of battery replacement outweighed the economic benefits of leasing, and the future state-imposed costs of recovery / recycling. When it comes to the Electric Car, I still think Edison had it right over a century ago.

The various screw ups and bad curry-like repetition of the Electric car idea is what happens when people who don't understand technology manage high tech projects, or make ill-informed rules to buy votes. No conspiracy, just everyday human cock-up.

2 comments:

Nigel Sedgwick said...

Thank you for a usefully on-target posting.

A while ago, under self-induced pressure arising from listening to those who would save the planet (I live here too), I considered how we use (nowadays) our energy resources, particularly of oil, gas and coal, but also of nuclear and hydro.

As you point out, the problem with electric cars is the batteries: storage of electricity. It seems the best energy storage and transport mechanism that we have for road vehicles is actually liquid chemical storage: ie petrol and diesel.

For warming our homes, especially in towns and cities (because of the piping infrastructure), piped burning gas is pretty much the best. For more rural areas, burning wood is cheapest, but less controllable; cylinder gas is also pretty good - it's certainly easier to transport and store than coal.

For generating mains electricity, hydroelectric is very good, but burning coal is now pretty much the best use for coal. [Note: I view using gas as a waste, except in so far as there is no better way to match very-short-term variation in load.]

These 3 things are, largely, what we do. Wondering why it has turned out that way, I suspect a combination of cost-effectiveness, personal convenience and business practicality, judged over decades by most of the people and most of those in the energy business.

If there are reasons to change this fuel usage pattern, it will change.

The problem with the 'green' agenda is that the claimed additional benefits (primarily saving the planet from CO2) does not overcome the additional costs, in the view of most people. Now, scrubbing NO2 and SO2 from power station effluent did make it; catalytic converters on all our car exhausts did make it; CO2 protection does not.

Perhaps the case is not persuasive enough to stomach the cost.

Best regards

Bill Sticker said...

Nigel,

Like you, I'm quite comfortable with the idea of scrubbing what I call 'proper' pollutants like Nitrous Oxide, Sulphur Dioxide and various particulates out of the atmosphere. They're reactive and have some quite unpleasant side effects. Carbon Dioxide however is a bit of a puzzler, the attention lavished upon it by those with a very poor science education is disproportionate, and I feel gets in the way of dealing with real Environmental issues.

Electric cars come from the same stable of ideas. They and the idea that you can control the climate by reducing Carbon Dioxide emissions have one thing in common; they're impractical. Sure you can do it, but neither is much good at what it purports to do. Quite candidly, they are very probably considerably more harmful to the Environment than the technologies they are supposed to replace.

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