Hacker News Reader

Comment by LifeLiverTransp | Hacker News Reader

My brother works at bmw, the problem is not that they dont see electric as the future, the problem is, that they see batterys as a dead end for cars. They are a ecological disaster to manufacture, have a limited life-time and are very slowly improving and have overall just taken off, because other industries basically carried that market.

If they could make the economics of scale happen, they would rather prefer something like lohc as energy carrier.

http://www.framatome.com/customer/liblocal/docs/KUNDENPORTAL...

Its storageable hydrogen, so its the natural product of decentralized renewable energy production. It has not recharge time, no battery decay. Only problem is- there is nothing but the car-industry who wants this.

View on HN

That sounded interesting - until I saw in the paper that:

1 litre of LOHC => 2 kWh

Cool? Except:

1 litre of Petrol => 9.7 kWh

(according to this: https://greennav.wordpress.com/2008/03/03/how-much-energy-in...)

I don't know about the accuracy of it, but I found this:

https://afdc.energy.gov/fuels/fuel_comparison_chart.pdf

...and it says that 33.70 kWh of electricity is the equivalent of 1 gallon of gasoline; since 1 litre is about 0.26 gallons - that's close to the other number (off somewhat though; 8.76 kWh instead of 9.7 kWh).

Regardless - it all seems to point to that either the tanks in a car would need to be 4-6 times larger - or the engines have to change in some manner to deliver the same level of performance with less energy - or something like that. Probably a combination of both.

I'm making the assumption that the LOHC would be carried on-board the vehicle, as that seems (?) like it would be safer and easier than carrying around compressed hydrogen (embrittlement issues, migration issues, consumer aversion perhaps). I don't know, though, if LOHC is more or less dangerous for consumers to handle like gasoline, or if the dehydrogenation process can be done on-board a vehicle; the paper doesn't go into such detail. It does safe it is safe to store and transport via normal methods, so it sounds like it might be ok in that regard for consumers.

Thank you for the reasonable discussion contribution, a rare thing around the fourth.

https://core.ac.uk/download/pdf/19496773.pdf

Well according to this paper lohc still has a better energy density then batterys and we would loose the recharge waits. Also existing infrastructure could be reused and it allows the indefinite storage and transport of renewables, if created at source with no additinal conversion loss.

As far as i know there are several varieties in research - with one condensend form (which isnt liquid- sorry im not really a expert on this) - beeing a factor 10 energy denser.

https://www.sciencedirect.com/science/article/abs/pii/S09268...

I think this one is the paper.. I can not say how serious these technologies are driven. The trad car companies have a lot to loose when the car is reduced to 4 engines and a steering wheel.

I still think lithium ion batterys have some use- as birthing help to alternatives, who would otherwise be stuck in development hell.

Remember that the thermal efficiency of an ICE is far lower than that of an electric motor, plus electric cars can use kinetic energy recovery so get even higher efficiencies.

That is a strange delusion on several levels. It looks lik downright psychological projection of issues with fossil fuels - and the fact limited lifetime also applies more so to fuels and hydrogen especially even.

Batteries currently have better effective energy density than hydrogen ironically given how heavy the tanks need to be to contain the metal embrittling escape artist that is hydrogen. Yet the traditional auto manufacturers bizzarely seem to have decided to make hydrogen their hill to die on.

You do not need those tanks for lohc, because the hydrogen is bound by a carrier fluid.

We can't afford anything but batteries for cars. The energy efficiency of wind->hydrogen/synth fuel->movement is just too bad. We don't have enough room for turbines to afford losing a factor 5 in energy efficiency.

Metal Alloys and Chemical Hydrides seem to be up there in 6 kWh/l zone though

https://www.researchgate.net/profile/Markus_Reuss/publicatio...

Not enough room? You can build a floating solar panel, that just ships over the ocean, generating charged LOHC which then is collected by a automated ship.

PS: If you look at the references of this paper you can see the BMW research that is referenced.

This is such a blatant lie. As if the petroleum and car industry really care about the ecological impact of battery manufacture, when there are multiple solutions currently proposed-

Tesla revealed they currently recycle the packs.

Use packs can be repurposed as house batteries for grid stability.

The data shows the battery lifespan far exceeds initial forecasted length.

Reply on news.ycombinator.com