Hacker News new | ask | show | jobs
by qznc 2747 days ago
But minus points because transfering the energy and storing it in a battery loses some.

Still, China is probably completely content with getting the pollution out of the city.

3 comments

An internal combustion motor is radically less efficient than power lines when comparing input to input.
Transmission loses 1-2%, batteries lose maybe 5%. Compare that to 30% losses for an ICE, above generator losses.
30% is the efficiency of the energy in fuel being turned into work.

You need to consider the efficiency of the power generation, power lines, battery and then the electric motor. Any other comparison is misleading.

Correct that his is thermal efficiency, and I apologize for not breaking into out earlier.

An ICE is ~20% efficient.

A combined cycle gas turbine is ~60% efficient, transmission systems ~98%, LiIon ~99%, motors around 85-90%. The first is thermal, the rest are electrical. Well-to-wheel this is about 50%.

My point was just that you really do get a large efficiency improvement (50 - 20 = 30) by electrifying cars. Climate argument aside, energy is simply being wasted.

And gasoline has efficiency of exploring, pumping, refining and transferring it (tankers, pipelines, trucks to the gas station)
That should be "China content with getting the pollution out of the tier 1 city". Those old diesel buses were probably moved to some tier 2 or 3 city to replace an even older fleet.
Isn't that exactly what they should do?