EEVblog 1480 - Lightyear Zero Solar Powered Electric Car

[EEVblog]

So it might be slightly better drag coefficient than other EV's, but that's kinda, meh.
If it got say twice the efficiency of other EV's on the maket then you might have something worth bragging about, but it's WLTP figure is only slightly better than my 2020 IONIQ.

Clearly this car is stupid as a product, simply due to the price, however....

The low drag coefficient is the key thing this car brings. Sure, you can find lots of demos of achieving a super low drag coefficient in a similarly shaped one person vehicle, but they've made a comfortable family car which achieves similar results. The WLTP figures are notoriously unrealistic. The range of most EVs goes down badly at high speed, mostly due to drag. If their claims are genuine, this car achieves a much more consistent range as the speed varies. People don't want cars they either drive at full motorway speed and spend lots of time at chargers, or spend less time at chargers but drive quite slowly.

I'm betting the "Highway range" includes the small boost from the absolute best the solar panels can produce. It claims 10.7kWh/100km at 110kh/h.
That's great, but not hugely or game changingly great, especially for the price. I'd have to double check my IONIQ, but IIRC it's in the order of 13-14kW/100km on the highway.

[McBryce]

EU agrees to end sales of combustion engine vehicles by 2035..

No, the EU plans to end sales of ICE cars by 2035. Nothing is cast is stone. There are several points in time where the plan is re-evaluated.

While normally I would frantically wave hands seeing “EU does foo”, in this case imo seems to be right. This week member states came to an agreement, which makes that statement correct.⁽¹⁾ The details are basically set and it would be a rare occurance for EUParl to reject those amendments. The fact, that those are corrections to a pre-existing regulation⁽²⁾, is important to see why it’s likely to see no further objections. Normally some factions would probably make an ineffective protest as a show for their electorate, but in this case a part of the framing is the situation with RF — so I suspect they may avoid even that kind of actions during the actual voting.

It is also worth noting, that this does not eliminate internal combustion engines. Regulation’s scope is limited to passanger cars and LCVs. Any other vehicle group is still covered by the existing limits. And while currently no viable option exists, fuels offsetting CO₂ emissions are not explicitly excluded either.

⁽¹⁾ https://www.reuters.com/business/sustainable-business/fight-over-funding-threatens-eu-deal-new-climate-laws-2022-06-28/
⁽²⁾ 2019/631

It will get interesting when they actually go to the bother of calculating how much electricity would actually be required to replace all ICE vehicles with EV. For a really rough estimate you can just check out the total energy delivered by petrol / Diesel imports to any country. Convert those billions of litres of fuel to watts and they will soon discover that we really need to start building a LOT of power stations / generators of some sort.

McBryce.   

[golden_labels]

It will get interesting when they actually go to the bother of calculating how much electricity would actually be required to replace all ICE vehicles with EV.

Dunno who are “they”. But avoiding financial losses is part of the reason EC has issued the proposal. So that future tense regarding doing calculations is a bit weird. In particular since the summary of the calculations is in the document you are commenting on. Another part of the motivation is decreasing investment risk for what you considered the cost in your calculations, so the amendment is literally answering your concerns.

For a really rough estimate you can just check out the total energy delivered by petrol / Diesel imports to any country. Convert those billions of litres of fuel to watts and they will soon discover that we really need to start building a LOT of power stations / generators of some sort.

As clearly indicated in the amended regulation, in the discussed amendment, in associated media reports and in the post to which you reply: the 0g/km limit affects particular types of cars, and only new cars. Emission limits for pretty much entire industrial use of fossil fuels in vehicles are not zeroed. So the basic assumptions for the above estimation are already wrong. If they were not, you are still completely ignoring everything other than arbitrarily chosen costs and then compare that to… right, what exactly are you comparing it to?

[McBryce]

With "They" I meant the politicians making these decisions. I am aware that my calculation is extremely rough and ignores lots of things, but it still doesn't change the fact that we will not have even close to enough electricity generation capacity for all of the EV on the road by 2035.
I am also aware of the details (new cars only etc), but even in this case many countries will be forced to build many new power stations to cope with even this and many countries haven't even started to increase generation at the rate we would need to charge the EV's.

So yes, sloppy maths, but it doesn't change the result: Not enough electricity generation or plans for new generators to cover the situation in 2035.

McBryce.

[nctnico]

With "They" I meant the politicians making these decisions. I am aware that my calculation is extremely rough and ignores lots of things, but it still doesn't change the fact that we will not have even close to enough electricity generation capacity for all of the EV on the road by 2035.

'Hydrogen' is the word you are looking for. The EU doesn't plan for all cars have to be BEVs; just that all new cars have no CO2 emissions.

[Marco]

Talking about hydrogen, I notice that farther in the past with just as much knowledge of the technical hurdles as now, and with actual running prototypes, liquid hydrogen was seen as a perfectly realistic solution even for passenger cars. Then somewhere along the way it got shoved to the side for the totally unworkable compressed hydrogen ... and I can't really understand why. Liquid hydrogen has downsides, but nowhere near as many as compressed.

The hydrogen evaporates eventually ... but ehh, so what? If it's connected to your inverter the evaporated hydrogen can be converted to electricity, so it doesn't entirely go to waste. To handle it running dry, have a limp to the pump battery pack in there too (good for heating up the fuel cell too when needed). Need to figure out some way for roadside assistance to attach a range extender so toeing the entire car doesn't need to become the go to for running out of hydrogen and power, a small hitch specifically designed for a toed battery pack perhaps?

Ignoring whether hydrogen is practical at all for a moment, I think liquid makes the most sense even for passenger cars.

[McBryce]

Talking about hydrogen, I notice that farther in the past with just as much knowledge of the technical hurdles as now, and with actual running prototypes, liquid hydrogen was seen as a perfectly realistic solution even for passenger cars. Then somewhere along the way it got shoved to the side for the totally unworkable compressed hydrogen ... and I can't really understand why. Liquid hydrogen has downsides, but nowhere near as many as compressed.

The hydrogen evaporates eventually ... but ehh, so what? If it's connected to your inverter the evaporated hydrogen can be converted to electricity, so it doesn't entirely go to waste. To handle it running dry, have a limp to the pump battery pack in there too (good for heating up the fuel cell too when needed). Need to figure out some way for roadside assistance to attach a range extender so toeing the entire car doesn't need to become the go to for running out of hydrogen and power, a small hitch specifically designed for a toed battery pack perhaps?

Ignoring whether hydrogen is practical at all for a moment, I think liquid makes the most sense even for passenger cars.

Because a tank of liquid hydrogen wouldn't get you very far. Liquid Hydrogen has an energy density of 2.8kW/h per litre, Compressed Hydrogen is 33.6kWh/kg. You'd need a massive tank of liquid hydrogen to get a decent range.

The other question is, where is all this hydrogen going to come from? There's no sources of natural hydrogen on this planet. There are a few other processes that produce it as a by-product, but not in the quantities required and other methods of producing it require massive amounts of energy and have high losses.

A third, rarely mentioned issue, is that most hydrogen is not 100% pure. It has impurities that gunk up the fuel cell pretty quickly. Most vehicle fuel cells only last a short time before they start failing.

McBryce.   

[iMo]

I talked recently to a guy working in a company messing with car chargers. Asked him the question on where all the energy comes from. He told me the energy, e.g. from nuke power plants, is here 24x7 in a constant amount, but most electricity is burned by the users in 2 peaks during the day and by industry 1/3 of the day. By creating a constant load during the day and night you may use it for charging all the cars (he told me "happily"). I am still pretty skeptical on it, though.
PS: Also with the news on the EU plan with ICE I registered an info (I do not have the source handy) "they" consider to double the EU nuke power station electricity production by 2050..

[McBryce]

Well I just did a closer calculation using real numbers, and using Germany as an example:

Germany produced 579 Billion kWh in 2021. In 2021 it sold 20.5 Million tons of petrol at the pumps (just petrol, diesel not included). A litre of petrol has 12.2kWh/kg. So the petrol sold was equivalent to approx 250 Billion kWh of electricity, meaning that Germany would need almost 50% more generation just to cover the petrol cars.
Not forgetting, 2021 was Covid shutdown, more electricity being used in home office and less petrol needed to drive to work.

The currently planned new power stations in Germany don't even cover the capacity that nuclear and coal fired generation supplied and which are now being shut down. So Germany is definitely not in a position to support this and I would guess that many other (non-nuclear) EU countries are in a very similar situation.

McBryce.

*All figures taken from Germany government sites.

[iMo]

Yep, EU has to reconsider the feasible energy sources.. EU and especially Germany had nice green project plans, but they did not evaluate all potential risks in their planning, like ie. the war in Europe. So they have to change their plans, it seems. In project management it is called a "change management process" which may result in more required resources, efforts, time (and $$)..

[Marco]

Because a tank of liquid hydrogen wouldn't get you very far. Liquid Hydrogen has an energy density of 2.8kW/h per litre, Compressed Hydrogen is 33.6kWh/kg. You'd need a massive tank of liquid hydrogen to get a decent range.

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

To address your tangent though, fuel cells are more efficient than ICE's and increasing a fuel tank by 50% in each dimension won't make it suddenly impossible to build a passenger car around it. Just like hydrogen aeroplane designs, the car designs can adapt.

A third, rarely mentioned issue, is that most hydrogen is not 100% pure.

Electrolysis of RO water has a lot less possible sources of contamination than from natural gas processing.

PS. I think material for PV can be massively reduced by moving to flexible solar mounted on plastic cushions inflated with expanding foam. Hail resistance can be handled like this. Etc. There's orders of magnitude of room to improve gigascale PV. That's where hydrogen will come from, if civilization persists.

[McBryce]

Because a tank of liquid hydrogen wouldn't get you very far. Liquid Hydrogen has an energy density of 2.8kW/h per litre, Compressed Hydrogen is 33.6kWh/kg. You'd need a massive tank of liquid hydrogen to get a decent range.

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

To address your tangent though, fuel cells are more efficient than ICE's and increasing a fuel tank by 50% in each dimension won't make it suddenly impossible to build a passenger car around it. Just like hydrogen aeroplane designs, the car designs can adapt.

A third, rarely mentioned issue, is that most hydrogen is not 100% pure.

Electrolysis of RO water has a lot less possible sources of contamination than from natural gas processing.

I'm not sure I understand what you mean. The tanks weight isn't really a factor here. Liquid hydrogen only has 2.8kWh/l. Petrol is 9.7kWh/l. So I would need a tank of about 3x the size of a current petrol tank to get the same range. I also need to drag this weight around with me. With compressed hydrogen I have 3x the density of petrol, so for the same range, the tank only needs to hold a third of the volume.

As for impurities. I've worked on two commercial Fuel cell vehicle projects. The fuel in both cases was produced using electrolysis and the fuel cells only had a meaningful life of just over 3 years before they were too gunked up to work efficiently. Additionally, producing hydrogen using electrolysis is incredibly inefficient (as low as 70%), so why not just use the electricity in a BEV instead of wasting 30% of the energy converting it to hydrogen?

McBryce. 

[Marco]

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

[McBryce]

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

Both far inferior to what? I can't answer this any simpler: To go the same distance, one needs a big heavy tank full of heavy fuel, the other needs a much smaller tank of equally heavy fuel. The weight of the tanks aren't much different per volume.

McBryce.

[Marco]

You can't answer it period, because you aren't reading the question.

Why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars.

[wraper]

Because a tank of liquid hydrogen wouldn't get you very far. Liquid Hydrogen has an energy density of 2.8kW/h per litre, Compressed Hydrogen is 33.6kWh/kg. You'd need a massive tank of liquid hydrogen to get a decent range.

And way more massive tank of compressed hydrogen. You compare apples with oranges. Liters with kilograms. For water the same number means equal amount but not for hydrogen.
Do you not see a problem in storing liquid hydrogen? Unless you keep it colder than -253^oC it will turn into gaseous form, so you need very good thermal insulation and to either let excess gaseous hydrogen into atmosphere to prevent the tank from rupturing or cool it by some means.

[wraper]

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

Both far inferior to what? I can't answer this any simpler: To go the same distance, one needs a big heavy tank full of heavy fuel, the other needs a much smaller tank of equally heavy fuel. The weight of the tanks aren't much different per volume.

McBryce.

The same amount of hydrogen in liquid and compressed form weights the same, but compressed hydrogen takes much larger volume thus needs much larger tank which also must be able to survive extremely high pressure .

[Marco]

Do you not see a problem in storing liquid hydrogen?

I was the one promoting liquid hydrogen, he was answering questions which weren't being asked.

I see the challenges of liquid hydrogen, but I don't judge them qualitatively different than liquid natural gas. A cryogenic fuel being commercially used in trucking today.

There's problems and risks, there are solutions and mitigations. The lack of energy density and charge-speed/grid-load of batteries is also a problem, the far far worse round trip efficiency of synthetic fuels made from green hydrogen is also a problem. The arable land and water use of biofuels is also a problem.

Which are the bigger problems?

[wraper]

There is a big difference between storing at -253^oC and -162^oC for LNG, even latter makes it very niche and troublesome. Not to say LNG has almost an order of magnitude higher density which require way smaller tank to be kept cool. Neither is a good option for any use that will be significantly intermittent. Basically fill and spend as fast as you can is the only viable option solution when using these.

[Marco]

BMW 750hl supposedly had about 1.2W heat ingress, that's about the latent heat of 2 mg of hydrogen per second. Lets say 5 kg of hydrogen tank, so that has a life of roughly a month. Lets say you include a small lithium ion battery and have the car run that down first. When you park the car, the evaporated hydrogen would first go to charging the battery.

It would require a different mindset from a fossil fuel car or EV, but I wouldn't say it's completely unusable simply because of evaporation.

[McBryce]

You can't answer it period, because you aren't reading the question.

Why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars.

It seems I really don't understand the question. All I can say is that I've seen the solutions for both systems in real hardware and the compressed gas solution was viable to put in a car for the ranges required with enough room for all the other things a customer would expect in a vehicle and the liquid version was not. Either way, neither are a viable solution as long as we don't have an efficient method of producing vast quantities of Hydrogen, which we still don't.

Maybe I need to ask the question: Ignoring the energy density aspect. We know the difficulties of keeping Hydrogen in a liquid form, very low temperature which requires both insulation and an energy source. To keep gas at pressure we just need a robust container. So tell me, what advantages do you see that liquid Hydrogen has over compressed gas?

McBryce.

[Marco]

Liquid hydrogen only has 2.8kWh/l. Petrol is 9.7kWh/l. So I would need a tank of about 3x the size of a current petrol tank to get the same range. I also need to drag this weight around with me. With compressed hydrogen I have 3x the density of petrol

I'm sorry I missed this ... in my defence, it's a really bizarre thing to say. Hydrogen can actually be liquid at room temperature, but it takes a hell of a lot more than 700 bar. Outside of extreme corner cases which are not relevant here, a gas of a molecule isn't going to be more dense than a liquid regardless of temperature and pressure.

The density of hydrogen at 700 bar at room temperature is 42 kg/m3, the density of liquid hydrogen at -252.87°C is 71 kg/m3. Compressed hydrogen has even worse energy density than liquid hydrogen, as common sense dictates. That said, I had never really looked at the Mirai tanks and it is kind of impressive how thin and light they were able to make a 700 bar tank. Eyeballing it the 750hl managed to pack it's 8kg of hydrogen in far less space including the necessary equipment than Mirai's 5 kg.

[tszaboo]

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

Because hydrogen is explosive. You can blow up it in the air, by shorting out something like a 10uf capacitor, that is charged up to 10v. That tiny spark has enough energy to blow up the car in your garage.

There is a big difference between storing at -253^oC and -162^oC for LNG, even latter makes it very niche and troublesome. Not to say LNG has almost an order of magnitude higher density which require way smaller tank to be kept cool. Neither is a good option for any use that will be significantly intermittent. Basically fill and spend as fast as you can is the only viable option solution when using these.

LNG is nice if you have a large tank that is maintained constantly. The issues start coming when that tank is actually used. So they never empty out LNG tanks to 0%. And when they are almost empty, the heat capacity decreases dramatically, while the heat gain of the tank is the same. So pressure builds up in them as the remaining LNG evaporates. And you can blow up an almost empty tank in a few days.
CNG is much safer for cars, because the tank is actually designed to handle the high pressure.

But I'm a fan of CNG. As I recall 60-80% of the car fleet could be converted to Petrol/CNG hybrids, significantly reducing the need for petrol. And we can create CNG from CO2 and water and solar or wind power. It's not perfect, but it would be a significant reduction of fossil fuel usage, even without the massive environmental need to make BEVs for everyone.

[nctnico]

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

Because hydrogen is explosive. You can blow up it in the air, by shorting out something like a 10uf capacitor, that is charged up to 10v. That tiny spark has enough energy to blow up the car in your garage.

This is FUD. In the end the same is true for fuel vapour. Why do you think fuel systems in cars are hermetically sealed? Research has shown that hydrogen has no higher risk of fires or explosions compared to other fuels used in cars.

[McBryce]

To reiterate the question, why was liquid hydrogen abandoned in favour of compressed hydrogen for passenger cars. Your supposed answer (you said "because") was energy density. Obviously the energy density and energy per weight including tank for compressed hydrogen are both far inferior, so it's irrelevant to the question at hand.

Because hydrogen is explosive. You can blow up it in the air, by shorting out something like a 10uf capacitor, that is charged up to 10v. That tiny spark has enough energy to blow up the car in your garage.

This is FUD. In the end the same is true for fuel vapour. Why do you think fuel systems in cars are hermetically sealed? Research has shown that hydrogen has no higher risk of fires or explosions compared to other fuels used in cars.

?? Show me the research that says that.

McBryce.