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Comment Re:Gamechanger (Score 1) 514

When electricity is cheap, it is because the marginal cost of producing it is low. The marginal cost is low because it does not take very much extra fuel to produce it. In other words, when electricity is cheap, its production is also less environmentally harmful. (This only holds as long as the power stations are unchanged of course.)

The Economist regularly gets this wrong by saying that electric cars are polluting more if they charge at night rather than during the day. They base this on the average pollution per kWh being higher at night. However, the average pollution does not matter. It is the marginal pollution which matters, and that is very low at night. This is really the kind of thing that economists should be specializing in getting right; I do not understand how you can be an economist and get it wrong.

Comment Re:Masstransit is more energy efficient than perso (Score 1) 280

DSB (Danish Railways) has a table on http://www.dsb.dk/om-dsb/dsbs-... saying that their long-distance trains do 33g CO2 per person km. Regional trains are considerably worse. Modern cars should hopefully do better than 133g per km.

Urban trains do better because people are standing up, which significantly lowers the train weight per person.

Now, Denmark is admittedly a bit of a developing country when it comes to trains. Obviously a pure electrified system running on hydro power would do a lot better. DSB's long distance trains use 0.12kWh per person km. A Tesla uses about 0.35kWh per km, which comes to 0.09kWh per person km with 4 people.

Comment Re:Show me the math on the Tesla. (Score 2) 280

That would be pointless because practically no one uses oil to produce electricity. Electric cars tend to charge at night where the coal plants are running at very low power and low efficiency. An idling coal plant has a very high average pollution per kWh produced but a very low marginal pollution per extra kWh.

Of course if it is a windy night the coal plants might just give up and shut down overnight, and then you really get your zero emissions.

Comment Re:Masstransit is more energy efficient than perso (Score 1) 280

Most other forms of transport have no chance against a decent modern passenger car with 4+ passengers. Most passenger cars are comparatively light, well below 500kg per passenger, which is very hard to beat. They do that because there is hardly any wasted space. A bus needs a walkway and it has to be tall enough to stand in, and trains are just horrendously heavy. While rubber-on-tarmac is a bit wasteful compared to metal-on-metal, it is not that bad, and the lower weight helps a lot.

Electric trains can sometimes play in that efficiency range, but it is tempting to make them faster and then the savings mostly evaporate. Cars are useful despite their lower speeds because of the time saved by almost going door-to-door.

Comment Re:Ada (Score 1) 211

It would be unusual if Rust was marketed as a functional language, because AFAIK no functional language exists without garbage collection today.

Comment Re:other stuff matters also? I claim it does (Score 1) 330

When it is merely cold, like -20C, electric cars are great. You arrive to a preheated and defrosted car and there are no problems starting the engine. 3kW of heating is quite sufficient when it includes heated seats and heated steering wheel, and that takes 3 hours to use 10% of the capacity of a Tesla 85kWh car. At slightly higher temperatures you can get a lot of benefit from the heat pump instead.

Now, lots of electric cars do not have suitably designed heating systems or batteries to handle -20C reliably. This is true of some petrol cars as well.

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