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Comment by hackbinary | Hacker News Reader

Okay, cool. But the energy still has to be produced somehow. Are we shifting the diesel to coal power plants? So for every km driven, what is the comparative amount of CO2 produced? Is there a net benefit in this regard? Coal power plants might be more efficient, but then we are shifting the smoke stacks.

Then what about the batteries? The batteries need to be produced, and they have a useful lifespan, then need to be disposed of or recycled. How do we deal with all of that contamination?

Are we further ahead with electric cars and buses?

I went to the Volvo museum last year and learned that pneumatic tires consume something like 30% of the energy expended by road vehicles, should we not be focusing on better rail transport? Or solid tire technology?

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Even producing electricity from non renewable in large power plants is better than using these same fuels directly: large power plants are much more efficient (close to 40% energy efficiency vs 30% for vehicle motors), and allow much more easily to filter out pollution, including CO2 capture. Sure going from diesel to coal would be bad, but going from diesel engines to diesel power plant would be a significant gain.

It is also a lot easier to shift centralized power generation (from coal to natural gas, to wind, import from neighbour countries) than across the fleet of millions privately owned vehicles.

Well, using electric vehicles does create more battery storage to charge using solar during daytime off-peak hours. You go to work, park your car in a parking equipped with chragers and your car charges while you sit and work. The parking lot and the neighbouring buildings can have solar panels on their roofs to supply the electricity. Same during night time off peak hours: you car can charge while you sleep mainly using excess nuclear or wind power. But this discussion is about public transport, which works equally better because during daytime off-peak hours people are mainly at work and half of the bus fleet can charge up.

I'm sure going electric is not 100% clean, but it displaces smog from the cities and power generation can be diversified and even distributed. So in many respects it's better. It's definitely better for urban transport where you don't need hundreds of miles of autonomy. The rest of the vehicles that go outside cities can be switched to plugin hybrids running on LPG and DME, which are cleaner alternatives to petrol and diesel. When they get into urban areas they can switch to fully electric if the transport code requires it.

Solar rooftops on cars don't provide enough juice for it to amount to much. Let's say for the sake of argument you could fit a square meter of a car's roof as a 20% efficient solar panel (a ludicrously high efficiency). Solar irradience is roughly 1 kW per square meter giving you roughly 200W. That will provide roughly 1.6 kWhr of energy. This is enough to drive roughly 8 miles on an average EV (20 kWhr/100 miles). That's about half the average commute one-way. Not nothing, but still invokes the question if it's worth the effort.

I am aware of this. This is why you need more rooftops than the parking lot's and your home's to produce electricity and feed it into the grid. Parkings could just buy that electricity, meter it and sell it to you along with the parking fee.

All power generation here in Norway is renewable, so the comparative CO2 amount is zero, or approximately infinite improvement over petrol.

Thank you all for the thoughtful replies and it seems to me that moving to electric transport is the way forward.

I would like to point out that the article in the main was about China, where they are building out significant coal capacity. However it does seem that on balance it does seem the right thing to travel to trade bus diesel engines for static coal generation.

The point is that you don't shift to coal power plants, you're supposed to get your energy from clean sources, such as nuclear, geothermal, and solar. You are presenting a false dichotomy, and engaging in whataboutism to create a distraction.

Maybe the batteries aren't very good for the environment, and maybe there are still problems to be solved with energy generation - it doesn't mean that it's not worth it to try to make our vehicles cleaner.

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