@freemo i'm primarily angry that battery electric gets pushed as if it is handed down directly by god. it's ok for things like renault twizy. for everything else it's inefficient because of the weight you have to move around. meanwhile diesel engines are rather efficient _and_ are durable. >200000 km are easily doable when they aren't abused. those diesel cars are now supposedly the work of evil and need to be replaced with new shiny cars asap (meanwhile air travel is fine and needs to be saved from the covid consequences..).

if hydrogen technologies were pushed, i'd be fine with it, but only asian companies seem to know how to build that 💁 hydrogen & green energy are a good combination, in part solving the energy storage problem.

a kWh costs 0.25€ here, so free charging is a big handout for people who are already wealthy enough to buy a new car.

@bonifartius This is wildly incorrect and not at all in line with the actual numbers.

Lets start with the weight argument. The average weight of electric cars are 1799 kg, the average weight of cars in general in 2018 was 1841 kg, at least in the USA. No electric cars dont have a whole bunch of extra weight, but its easy to understand why, with an electric car you have batteries, and then one to 4 motors directly attached to each wheel (at least in the favored design of current electric cars). You eliminate a great deal of bulk needed in a traditional car from the engine block to the transmission (sorta), to the drive train, the differentials, a whole bunch of big thick chunks of metal arent there. Yes you also add things like batteries. So in the end the weight is actually very similar.

Also lets address the efficiency issues. This is almost completely untrue outside of a few fringe cases. In terms of the efficiency of the energy stored on board Electric cars are **significantly** more efficient. A petroleum based car has between 19% and 21% efficiency of the energy stored in the gas that actually gets used to drive the car. The vast majority of the energy is lost as heat. However modern electric cars coventry their onboard energy stored in the batteries at 80% efficiency. so if we talk about the cars electric is more efficient by a huge margin.

This makes sense when you consider that each time you convert energy to one form or another there is loss, so a principle of efficient design is direct utilization. gas goes from chemical, to heat/explosive, to linear moment, to angular moment. Each step has significant loss involved. Electric motors however convert the EM of electricity directly into angular momentum, and thus have far less loss and are far more efficient.

Now the only time you can start to argue there is an effiency advantage to gas based cars is when your electrical grid is 100% (or near to it) based off of gasoline or a similarly inefficient power source, in this case you would indeed be correct that start to finish your gas car will have a bit of an edge, however in reality that isnt the case in a single country. The USA is less than 0.1% oil based energy production. The vast majority (for example 75% in new england states) come from a combination of nuclear, hydro, solar, and wind. All of which produce electricity directly and as such an electric vehicle is **significantly** more efficient even when you consider the energy production all the way to the vehicle.

Hydrogen has its use in a few special situations but overall hydrogen tech for cars would be less efficient (significantly so) than electric. There are no nature sources of hydrogen, all hydrogen is produced from non hydrogen sources, for example hydrolysis, which is very inefficient and requires electricity as the input... So instead of running off the electricity directly first you waste half of it converting it into hydrogen, then stick it into a car that uses explosions to turn that into motion which as we already established is very inefficient and wastes another half or more of that energy. So that isnt a solution in most situations, not on its own.

@freemo i'm a bit short on time, so a bit terse:

as you have descibred the losses in conventional cars, there are losses in power generation as well. The only thing really generating electricity directly are photovoltaic cells, but only with an efficiency of ~20%. Everything else is heat to rotation to electricity, i don't have a good link, but nuclear is around 40% efficient. Then we have grid losses, etc. I don't know how efficient the charging electronics are, but there will be losses too. So its say 30% efficiency from the grid and 80% efficiency in the car. Which then hauls half it's mass in half empty batteries, on average.

I was talking about hydrogen electric, hence my remark that only asian companies can build that. It's not perfect either but at least hasn't the environmental problems associated with Li-Batteries. Hydrogen storage is a bit tricky, but it's not unmanageable either. Refueling takes a few minutes compared to charging over hours (or damaging the battery by quick-charging).

Storing energy of green sources as hydrogen is good as the energy isn't lost over time and no batteries which get worse with each cycle. Additionally it's rather easy to move it then.

Another thing which is interesting are synthetic fuels, but i don't know that much about it. Supposedly there are ideas to convert co2 to methane using electricity and hydrogen.

@bonifartius Well I did describe the loss in a conventional car, its ~ 80% loss within the car compared to the electric which was ~20%

What you describe is **not** the loss in the car its the loss in the energy generation process, as you point out. Thats fine and its relevance and worth talking about, but lets be clear we just moved the goal post, thats fine goal posts should be adjusted, but just saying.

As you seem to recognize when we talk about effiency and energy it all depends on scope. The largest scope we have on the earth for almost all forms of energy is the sun. The sun is our source for solar, wind (heating of the air), petroleum/gasoline (which comes from plants that got their energy from the sun), hell even nuclear energy is technically fissile material that comes from the sun.

We can at any point pick a scope to consider and evaluate effiency to absurdity of course and even start talking about the effiency of the sun itself, or the effiency in generating stars from other stars through super nova, you can go on forever. So the question we need to ask ourselves is simply what is the proper scope for the problem we are discussing.

Take solar panels as you brought up as a prime example of this. they are indeed only 20% effiency at converting EM radiation (light) into electricity. thats true, but is it relevant? Plants are half as efficient converting only 10% of light into energy. They also use a lot of that energy and only about 0.25% to 0.5% gets stored into the crop. An even smaller portion of crops and their energy make it in the ground to turn into oil. So we could safely say the process of converting light into petrol/gas is far less efficient at <0.1%... but again does this matter, why does evoking effiency this far up the chain matter in our discussions at all? What effect makes this useful and relevant to the discussion?

@freemo my point is that most energy is currently produced using fossil energy sources, the conventional car directly (sans refinery energy usage) uses it. For battery electric it gets converted from heat to rotation to ac electricity to dc to chemical energy and then to electric energy again.

@bonifartius No that is completely and absolutely false in the USA and most countries.

In new england for example only 7% of the energy comes from fossil fuels. Moreover the fossil fuels used to generate energy for the grid isn't even gasoline or similar. It is other things such as natural gas and coal, neither of which do we have any production cars that run off either. So again, not sure how that is relevant. Even if we look across the USA as a whole fossil fuel generation for the power grid is less than other sources.

@freemo my wording should have been "renewable" vs. "non-renewable" energy. nuclear fuels won't last forever.

in germany we have about 13% nuclear, 40% coal, 14% natural gas, and 30% renewables (https://www.umweltbundesamt.de/sites/default/files/medien/372/bilder/strommix-karte-2016.png from 2016).

the conversion from non renewable to electricity and then mechanic energy is as lossy as just using non renewable directly.

there are more interesting technologies for storing energy than batteries, and i think if batteries are established as status quo, we will be stuck with that.

sidenote, coal can be liquified, which is in use at the moment, see https://en.wikipedia.org/wiki/Coal_liquefaction . it's really inefficient, but in south africa your car might be a "coal runner" ;)

funny how a rant while driving leads to such a discussion :)

@bonifartius @freemo I found an article speculating on how long our uranium and thorium supplies could last, if we used them exclusively for fuel. (at least 100,000 years if we use no other power generation, consume as much power as an NYC resident and sustain a population of 10 billion). It’s certainly nothing compared to the remaining lifetime of the sun.

If we don’t drive ourselves extinct in 100,000 years, I imagine by then we’ll have figured out a viable way to put solar panels in space.

As for electric cars, I think they’re dumb. We should build more trains.

@cy

Actually nuclear fuel does last forever and is renewable. So again this is a failure if fact. Breeder reactors are capable of generating energy and actually produce fuel as thry go rather than consume it. They start with a seed amount of fuel and then never need nuclear fuel again as it produces its own fuel as it generates energy. Thus nuclear fuel is both able to last forever and renewable by definition. We currently have 21 breeder reactors in operation around the world whose excess fuel is them capable of being used in nonbreeder reactora.

@bonifartius

@freemo @bonifartius Breeder reactors can’t break the laws of physics. The fuel they produce is always less than the fuel they consume. Even though they’re not renewable though, it is nice that we can recycle nuclear waste in them, except for the fact that the only way I’ve heard to filter out the remaining useful fuel is using pressurized high temperature hydrofluoric acid.

If they can get past the whole “begging to die as your bones dissolve and your blood coagulates from the inside out” issue, I do think breeder reactors are a very good way to extend the useful life of nuclear materials.

@cy

Please try to educate yourself on a topic before you start asserting things as facts...

> Breeder reactors can’t break the laws of physics. The fuel they produce is always less than the fuel they consume.

They **do** produce more fuel than they consume, this does not break the laws of physics.

There is no violation of the laws of physics, it isnt creating free energy, nuclear reactions derive energy from mass energy equivalence, the conversion of mass into energy. Because they convert non-nuclear material into nuclear material due to an excess neutron economy they are able to turn non-fisible material into fisible material. Since the energy in nuclear reactors is derrived from conversion of mass into energy it does not violate the laws of physics, it turns ordinary inert rocks into nuclear material and a fuel source.

Yes it is renewable, yes it is effectively infinite (so long as you have any matter/mass to convert at least, which is effectively infinite considering how little is needed)... and no it doesnt break laws of physics. Here is a quote from wikipedia confirming what I just said

> A breeder reactor is a nuclear reactor that generates more fissile material than it consumes.[1] Breeder reactors achieve this because their neutron economy is high enough to create more fissile fuel than they use...

@bonifartius

@Demosthenes there would be much less requirement for developing infrastructure if only the fuel would be something like a liquid. as it is, battery charging requires bigger connections everywhere (including digging trenches, etc.), while fluids just are "another pump" mostly. there is no oligarch hyping that though.

@bonifartius current _battery_ electric cars seem like letters of indulgence, only for greenwashing.
not eating meat and not flying would buy at least a few years wrt global warming. that seems to be too hard for people to do though, especially the not flying part.

@bonifartius liquids would require a massive amount of infrastructure too, particularly when considering the long-term costs of liquid distribution. No matter our choice, new infrastructure needs to be made.

"not eating meat and not flying would buy at least a few years" This is true, but as you mention, it's unfeasible. Such cultural change overnight is not going to happen.

It's time to be pragmatic and make steps towards decarbonization now. If we wring our hands and wait for a perfect solution, another several decades will pass and we will risk becoming Venus.