from their website: hydrogen fuel cell: 70 kW volume of the hydrogen tanks: composite tanks 5x312l So the content of the cylindrical tanks is more than 1.5 m³ The bus is driven by an axle with two integrated electric motors, each with an output of 125 kW. Solaris indicates a range of up to 350 kilometres. This is exactly (only) as much power as the standard range Tesla model 3 (250 kW), with a range of 409 km. If triple the amount of batteries were included in the bus as in model 3, they would surely provide more than 350km in the bus. The "old" Tesla batteries are around 260 Wh/kg or 711 Wh/litre. The newer Tesla batteries are even (much) better. So, a 200 kWh battery would weigh about 770 kg, and have a size of 281 litres. (somewhat more due to the power electronics, packing and cooling system) Compare this with the huge H2 tanks of 1500 litres internal volume + the fuel cell. A battery bus would be much, much cheaper, much more reliable, and consume 1/3 the amount of primary electricity than with the wasteful hydrogen. City busses are particularly suitable for batteries as they can be charged intermittently (but even then, with a 200kWh battery, a city bus would probably hardly have to recharge during the day) Placing a number of chargers is also immensely cheaper in installation and operation than a hydrogen fueling station. From an ecological point of view, it wouldn't waste 2/3 of the electricity through the wasteful H2 cycle. Even more importantly, it wouldn't provide an excuse to the fossil industry to "green" their image as the H2 provider while still producing H2 from fossil fuels and dumping the CO2 in the atmosphere. This last point is most probably why H2 busses are proudly promoted. I cannot imagine that the politicians are not capable of making this simple calculation and independently come to the obvious conclusion that batteries are much more economical and ecological.

or a detachable supercapacitor/battery pack to get the plane to an adequate altitude, which subsequently disconnects and glides back to the launch site to recharge .

Mass production of H2 through steam reforming of biomass and waste, combined with CCS, could pull gigatons of CO2 out of the air. Also cement production emits gigatons of CO2 which must be sequestered. Even in the complete abcense of fossil fuel use, gigatons of fossil CaCO3 is turned into CaO + CO2. The CaCO3 are fossil chalk skeletons from ancient micro organisms.

If they really succeed to produce 1.5 million tons/year of green ammonia, that would be remarkable, but the world production of all (=fossil) ammonia in 2019 was only 171 million tons. It would make the most sense to first replace the fossil NH3 with green NH3 before, which would already be great. It would make much more economic and ecologic sense to first replace all fossil NH3 by green NH3, and only then start "burning" it. Building an industrial-scale production and transportation infrastructure for green NH3 is very sound, but it seems to be way to early to consider 'burning' it as fuel, as when (most optimistically) they will -by 2025- hardly replace 1% of world fossil NH3 production. electricity --> H2 --> NH3 --> H2 --> electricity (FCEV) is much less efficient than electricity --> battery --> electricity (BEV), so as long as we don't have dirt-cheap excess electricity, it would be more sound to use electricity as efficiently as possible.

This approach Sems to me enormously inefficiënt compared to fuelcells, and certainly compared to batteries Massive production of green NH3 Will be beneficial through.

Doesn't matter too much where the CO2 comes from at this moment. Fossil fuel will be uneconomical soon anyway, so more ecologically sound sources will eventually be used. It's good this tech is developped for industrial production of chemicals (and some fuels) from air-captured CO2 in the future. Also exhaust from waste or biomass incinerators is a flue gas. Pyrolysis of biomass is great for carbon sequestration but still produces also CO2. This could also be used. Cement production, even when using renewable or nuclear heat, produces lots of CO2. this can be turned into plastics via methanol.

Nice, but why use it as a fuel. It remains fossil carbon, that is only used a second time, but eventually is released into the atmosphere. If used as fuel, it is an extremely inefficient use of electricity and an apology for ice users. Moreover, the EtOH is probably very pure, which is unnecessary for fuel. Use it in the chemical industry.

While not efficient for driving cars compared to batteries, green H2 production using excess renewable electricity would be perfect to absorb immense amounts (and doeing so prevent immense amounts of CO2 emissions). Currently H2 is produced by steam reforming (see wiki): for every ton of H2, 9 tons of CO2 are emitted. The US currently produces about 10 million tons of H2 per year. If green and cheap, H2 can be used for many other things, preventing CO2 emissions. One major application would be Iron production (currently iron ore is reduced using carbon, releasing CO2. This can perfectly be replaced by H2, releasing water. (Fe2O3 + C --> Fe + CO2 /// Fe2O3 + H2 --> Fe + H2O) (if an electrolyzer is at the production site, the H2O can be reduced to H2 again and reused ; since the H2O is already extremely hot, this saves on energy)

Anyone buying such ICE Cars should know the residual value in a few years will be almost Nothing because supply/demand for used ICE cars Will be grossly out of balance. For BEV cars it will be the oppositie. This taken into account, why buy an expensive inferior car if you van buy a cheaper but superior alternative?

Typo: ... (Slowly) taking off.

Great that industrial scale green H2 production is (slowly). Even if H2 is never used as fuel, we will need gigatons per year for industrial applications.

Small addition: producing charcoal does not liberate free O2. The oxygen in the biomass is released as H2O. It is plants growing that releases O2. But you must prevent the biomass from decaying into CO2 again to keep the O2 in the air. For this, turning the biomass to charcoal or plastic or furniture will work.

Indeed, every carbon burnt is turned into CO2, even more, hydrocarbons are turned into CO2 and H2O, taking even more O2 out of the air. So for every CH4 burnt, two O2 molecules are lost. Luckyly, there is a lot of O2. 21% O2 = 210000 PPM, while CO2 is at 400 PPM. So even trippling CO2 to 1200PPM would consume about 1500PPM of O2, thus decreasing O2 from 21% to 20,985%. This decreases the partial pressure of O2 only as much as going opstairs about 10metres or so. Turning biomass to charcoal (= pure carbon) or nanotubes would liberate the O2 again. Also making aluminum from bauxite liberates a lot of oxygen if done with nonfossil energy. Interestingly, all the O2 in the air comes from vulcanic CO2, of which the carbon is sequestered by ancient organisms and the O2 was released

Could anyone explain how you can generate energy by concentrating CO2.? It violates the second law of thermodynamics.

Keep using fossil fuels (untill truely renewable fuel is available) and planting forrests on the areas now wasted on sugar cane and corn is much more defendable than this destructive dead end.

Only quantifying the polution on particle size is obviously practical and simplifies comparison and statistics, but it is an oversimplification of health effects. The effect of a dustgrain depends not only on its size but also largely on its chemical composition. For instance, a grain of NaCl of 2.5 um is completely harmless, while a grain of asbestos or sooth is not. Sooth of ICE exhaust is probably much more harmful than the inert particles of tires

"particularly in cosmetics" this will replace huge amounts of petroleum. I hope they have other applications, and that the economics also work for less high-end products.

coal has no future for many reasons. These technologies, however, will be useful for many other applications. Higher efficiency steam turbines will be useful for nuclear and concentrated solar. materials for ultrasupercritical powerplants is also good for high-temperature nuclear, and high-temperature electrolysis. subsurface carbon storage will be needed to actively lower atmospheric CO2 using direct air capture or CCS of biomass/waste. recovery of rare earth elements or toxic heavy metals from coal ash can be done with the megatons of coal ash we already have, or to extract those elements from low-quality ores. If some politicians like to sell the development of those technologies as "coal promotion" for political reasons, I grant them the pleasure. At least it will be used for entirely different applications, and it is not immediately harmful to the planet. By the time these technologies are developed, and coal is history, they will be used in advanced nuclear plants, concentrated solar plants, high-temperature electrolysis, wind turbines, electric cars and geoengineering. Those technologies may even hasten the end of natural gas. At least coal proponents can do a last useful act before finally admitting it's over.

Li is great, so hopefully Mg is even better. The more options, the better. Nevertheless, even if Li is the best option, there will never be real scarcity since it can be extracted from seawater at limiteless volumes. Admitted, there is even much, much more Mg in seawater. But still, the amount of Li available is vertually infinite.

Interesting and useful concern. However, such kinds of algorithms can be monitored and legally regulated. Moreover, once fully autonomous driving electric cars are available, taxies will be so cheap and convenient that they will most probably take over private driving. A taxi ride will probably be much cheaper than the parking charges today. An electric car that can drive 1,000,000 miles before it needs to be replaced, and costing $50,000, costs about 5c/mile capital investment cost. The "fuel" cost is less than 2c/mile. Let's say a "total overhead cost" of 5c/mile. Total : 12c/mile . Free competition will ensure reasonable profit margins, so this will be much cheaper and more convenient than driving your own car.

1 ppm of co2 equals about 7.81 gigatons of CO2. decreasing the atmospheric CO2 from 410 ppm to 250 ppm level of two centuries ago would cost about $37,000 billion. Not too much to save the planet, if we need a plan B

@Roger: they do direct air capture (climeworks). Even if no liquid organic fuel is needed in the future, we will still need gigatons of plastics. Wheen cheap green energy will be abundant, it will be obvious to make them locally from air. Certainly for countries with no domestic crude production, and with a correct carbon price.

I doubt many people will be willing to damage the batteries of their cars to stabelize the grid. EV-batteries are too expensive for this application. And people prefer having their car battery fully charged whenever the want to start driving. Mass-produced dedicated battery packs (which are cheap because often second-hand cells) would be preferable I foresee. The technical requirements for a stationary battery pack is also very different from a driving and crashable car. Waste heat from charging/decharging can also be used more cleverly with dedicated stationary systems.

I fully agree with PE. The greatest advantage is that it will permit high-power delivery at locations where the grid wouldn't permit it through smoothening of the load, and to optimize the use of renewables and nuclear. Mass production of such units will permit higher penetration of renewables and better utilisation of nuclear. Great evolution.

I love the idea that there seems to be no other metal used than magnesium. The organics can be made from carbon and at end-of-life be completely destroyed to CO2. The Magnesium can be extracted from seawater, and at the end-of-life recycled or returned to seawater. This is the ultimate circular economy, very environmentally sound, and endlessly scalable (which is not the case for cobalt). Even if power density and capacity is not optimal, this is a great chemistry for stationary batteries.