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Comment by iamsb | Hacker News Reader

Curious - how much impact we would have on global warming if each and every car currently running is electric? Given that most of the electricity is provided by fossil fuels.

Dont want to come across as a denier, this is a genuine question.

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Could only find numbers from the EU, but there passenger cars account for ~18% of total CO2 emissions. Everybody else seems to report cars and trucks as one group so it's hard to estimate how much of that impact is cars.

The overall losses between the power plant and consumers is in the range between 8 and 15%. An electric motor typically is between 85% and 90% efficient. Conventional gasoline vehicles only convert about 17%–21% of the energy stored in gasoline to power at the wheels. State-of-the-art fossil fuel plants at 46% efficiency. Using average values gives a ratio of 46x0.885x0.875/19=1.87 (electric almost twice as efficient). This calculus has not taken into account transport and filling the tank and older fossil fuel plants (maybe they compensate each others).

You should also take into account the embodied energy of the battery which is currently produced with fossil fuels. That narrows the efficiency gap a lot.

Yes building an electric car requires more energy than building a conventional vehicle. According to https://www.quora.com/How-much-energy-is-required-to-build-a..., this requires 2.1 year to amortize the difference.

Probably a rather small impact. On the other hand, replacing all energy consumption but transportation with carbon free alternatives isn't enough either.

Global warming doesn't have a simple solution. We need to attack a large number of problems simultaneously if we want a chance to prevent catastrophe.

I was hoping for a number, like say 1%. I wish there was a website which shows you exactly what are the causes of global warming and how much they contribute to it, preferably by industry and country. For example a small country like Australia which has less than 1% of human population, contributes enormously (15% of methane due to animal husbandry) but there is very little being done in that country to control this.

ipcc.ch

From the proverbial horse's mouth.

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