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161 comments on Australia: What to do, what to do about our energy situation?
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The electrification of railways only works at reducing emissions if we get rid of coal-fired plants. Currently in Australia electrified railways are responsible for more emissions per passenger or tonne-kilometre than diesel rail because of where the electricity's coming from.
Figures?
Electric traction is 4 - 5 times more efficient than ICE traction. Even though the burning of Coal produces more CO2/kWh than Oil, I doubt it's 4 - 5 times as much.
Generating a kWh of electricity from coal (one-through, no combined cycle/gasification/whatever) emits about a kilo of CO2, basically 1:1. I don't have the figures for trains handy, but a EVs (car) regularly get 200Wh/km, so effectivly emit 1 kilo of CO2 for every 5km travelled, or 20kg/100km.
Looking at the BP website, Petrol emits 2.3kg/Litre. If a modern ICEV get's 9.4L/100km (2008 Pertol Mondeo), that's... 21.62kg/100km. Almost even.
Diesel emits 2.63kg/km. The Diesel Mondeo gets 7.4L/100km, so that's 17.28kg/100km. Better, but still almost even.
Over 25,000km, the difference between Coal (EV) and Petrol is 405kg of CO2 in favour of coal, and between Coal and Diesel is 680kg in favour of diesel.
Over the cars lifetime, say, ten years, and assuming it's maintained properly (hah!), the differences would be 4050kg and 6800kg respectivly.
These figures would indicate that you are right, and that it would be better to buy Diesels rather than Electrics. However, the scope to improve the efficiency and reduce emissions is much, much greater for electrics than it is for diesels. Shutting down a Coal plant and replacing it with CSP+PS yields an instant improvement. I don't like the odds of having much Diesel in ten or twenty years anyway.
Thus, I don't advocate killing off Diesels, but rather putting the emphasis on Electrics and cleaner generation.
Subsitiuting Oil fuels with something else is still problematical. We can use Anhydrous Ammonia (generated with Green electricity, Nitrogen from the Air, and the last step of the Haber Process) in ICEVs without, apparently, too much modification, but we might as well just use the electricity directly if we can.
Once a train is moving, it doesn't take much energy to keep it there. Where electric traction shines is in tractive power (ie, getting stuff moving). You just have to look at the QLD coal fields to see the motive preference.
It may be worthwhile to realign the railways, but given the tractive benefits, it may be better to focus on simply electrifying the lines.
You're underestimating emissions due to coal-fired electricity generation. It's not 1kg CO2e/kWhr, more like 1.3 kg CO2e/kWhr.
According to the National Greenhouse Office,
But we have to consider not simply the emissions compared to electricity generated, but emissions compared to electricity actually reaching the lines above the tracks. If for example a power station emits 1,000kg of CO2e while producing 1,000kWh, but 250kWh are used by the power station, lost in transmission and so on, so that only 750kWh reaches the electric train, then we must in all fairness look at the total emissions of 1,000kg CO2e compared to the useful energy of 750kWh. So instead of 1kg CO2e/kWh we get 1.33CO2e/kWh.
The UIC, drawing on printed sources, says,
So we get that of all electricity generated, 83.3% goes on to be actually used for some end purpose. But we can look at more raw numbers if you prefer. To be generous to electricity and its emissions, we can compare 2006 generation with 2005 emissions.
So we have 279.4Mt CO2e emissions for 210 billion kWh useful electricity, and thus 279.4/210 = 1.33 kg CO2e/kWh. That's for all electricity sources - coal's obviously higher, wind turbines obviously less.
So going on your figures of 200Wh/km, electric cars hose electricity comes from our current mostly-coal generation mix will have effective emissions of 0.2*1.33*100 = 26.6kg CO2e/100km. There is thus no greenhouse emissions advantage in electrifying transport if the electricity generation remains in its current high fossil fuel mix.
The other thing to consider is that electric vehicles generally require more energy - and thus usually more emissions - to produce than internal combustion vehicles.
[original source: Institute for Life Cycle Environmental Analysis, site apparently now defunct, however the study was led by this guy at Seikei University]
I don't know of any studies of complete life-cycle analysis of electric vs diesel or other trains, but I don't see why they'd be that different to electric vs petrol etc automobiles. A train's diesel or electric engine is not magically different from a car's. So I'd expect to see the same results: that electric vehicles have more emissions than fossil fuel driven vehicles in manufacture, but that emissions during use depend on how you get the electricity.
Basically, it's as I said: if you get your electricity from fossil fuels, it makes not much difference to total emissions whether the fossil fuels are burned in a power station or on the vehicle. But if you get your electricity from renewables then electric's the clear winner overall.
Thus, it's not enough to electrify transport, we need to reduce emissions due to electricity generation. Or else we're just shuffling the pollution to a different spot, overall it's pretty much the same.
A powerfull argument.
I think this post of yours and my previous post are agreeing with each other? I.e. no net benefit as things stand but the potential for enormous improvements in the future if we electrify.
I have no idea if the LCA you cite took into account that EVs generally last longer than ICEVs.
But if you're including line losses in your calculations for Electricity, you should also include transportation losses for fossil fuels (from, say, the refinery to the vehicles tank). It's only intellectually honest. Otherwise we're comparing Oranges with Mandarins (almost the same thing, but not quite). We could go all the way bac to Mine -> Rail and Resiviour -> Rail, but things start getting fuzzy.
One advantage the electric traction has over motor vehicles or domestic users is that the lines use higher voltages, so line losses are reduced.