Synthesize carbon neutral jet fuel using carbon-free heat and power. Inputs of CO2 and H2O. In other words, use nuclear power.

Synthesize carbon-neutral jet fuel from CO2 and H2 using nuclear power. Don't burn fossil fuels and then try to capture some of the resulting CO2 from the air. Surely that is doing things the hard way.

@Roger--How does the aircraft handle the shifting CG if you put all the mass of LH2 at the rear of the airplane? Keeping a stable CG is one of the reasons aircraft are designed with wing fuel tanks, since wings are generally located so lift is at CG point, more or less.

Carbon-neutral synthetic fuels make a lot more sense if you want to continue with internal combustion engines. Make a gasoline or diesel drop-in replacement that uses existing fueling infrastructure. Of course that doesn't require you to make cool new engines.

Consider the infrastructure challenges of storing and distributing LH2 compared with synthetic kerosene, which can use existing infrastructure. Consider the need to build a fleet of completely new aircraft types compared with the ability to drop synthetic kerosene into existing aircraft. This is a silly idea.

Perhaps a more realistic solution is to lower the carbon footprint of the existing fleet using low-carbon, drop-in synthetic fuels, which could be produced with nuclear heat and power. Simultaneously, transition to a more electric fleet over time. The popular myopic focus on renewables as the only visible solution to decarbonization is striking, considering the potential for clean, abundant nuclear energy is just sitting there mostly disregarded.

Seems like a good match for a high-winged transport like a C-17.

No cobalt, no lithium, just abundant sodium and nickel. We're talking scalable.

@SJC: Core unit (including graphite) is swapped out every 7 years to avoid the problems long term graphite irradiation (swelling, etc). Terrestrial Energy knows what they are doing.

Very clever design--eliminating a helical gearset with its axial thrust has got to improve efficiency. I wonder about wear/longevity of those sliding segments. Wish them luck--lowering motor speed for highway driving should be great for increased range.

One very expensive status symbol for most buyers.

If you have a source of biogas, why not just that for your energy needs? Seems like it would be a lot simpler and less expensive.

Smart. Screen/test, isolate, rinse, repeat.

Traditionally, putting propellers far from the fuselage creates a hazard should one fail during takeoff--pilot has to manage the turning moment from single engine on one side. I suppose this isn't such a problem with the smaller takeoff/landing motors along the wingspan.

@EP: If I had to guess, and looking at the graph, large hydro (imports from Pacific NW) declined, natural gas increased, coal is already marginal. Just wait until the ill-advised shutdown of Diablo Canyon in 2025.

"...spontaneous power delivery..." Not sure that's what you mean to say--I'd rather not have my car accelerate spontaneously.

Per SJC, best use case may be for larger scale, stationary applications, where taking off a stream of nitric acid becomes a benefit, not a burden.

I assume the fuel cells need a supply of H2 (from nat gas, bio gas, syn gas) as well as CO2 from flue gas, so the additional power generated is not exactly 'free'. However, good work on a more efficient way to sequester CO2.

@mahonj: 60 MW/unit latest version, FYI.

The world needs *cheap* green energy. Cheap energy is the foundation of prosperity in the modern world. There is no reason (besides entrenched interests) that affordable, safe, clean, nuclear SMRs could not be powering our world.

As far as load-shifting storage for a NPP, I am curious to compare the capital and operational cost of energy storage vs just scaling up the NPP and load-following. In the latter case your NPP capital cost goes up and capacity factor goes down, of course, but you avoid the cost of storage. For intermittent renewables the need for backfill of capacity is mandatory, of course.

Another way: synthesize low-carbon liquid fuels using nuclear heat & power. Also decarbonize the grid with nuclear. The solutions are out there.

Replace the renewable energy source with a small modular nuclear reactor and then you've got something.

@Davemart: please check your math.

Gotta start leaving that carbon in the ground. Oil company balance sheets show these reserves as assets. They are going to go to the mat against anything that impairs those assets (e.g. carbon tax, whatever). This is the fight of the 21st century.