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We Still Have No Idea How To Eliminate More Than a Quarter of Energy Emissions (technologyreview.com)
Climate discussions typically center on the need to replace fossil-fuel power plants with technologies like wind turbines and solar panels. But a new paper in Science offers a stark reminder that there are still huge parts of the global energy system where we simply don't have affordable ways of halting greenhouse-gas emissions. MIT Technology Review: Air travel, long-distance transportation and shipping, steel and cement manufacturing, and remaining parts of the power sector account for 27 percent of global emissions from the energy and industrial sectors. And the authors say we need much more research, innovation, and strategic coordination to clean up these sources. "If we're really ambitious about meeting our climate targets, we need to be tackling these hard sectors now," says the paper's lead author, Steven Davis, an earth system scientist at the University of California, Irvine.
If the headline is correct, that means we can eliminate 3/4 of energy emissions. That sounds like a win to me.
You are welcome on my lawn.
A nuclear plant could easily power a processing plant to produce methane from the CO2 in the air and water (Sabatier reaction). The high energy density of liquid methane fuel can then be used on aircraft with a net-zero carbon footprint. The net effect is a "nuclear powered airplane."
Many steel plants already use induction furnaces for for melt processes, but the addition of coke to remove impurities is a required part of the process. Using induction heating with a much smaller carbon injection reduces the footprint from steel production, while CO2 capture and electrolytic splitting becomes possible with massive energy sources. In other words, capture the CO2 that does come off, and re-split it to carbon and oxygen, which also lets you re-use the carbon on the next batch of steel. Bonus.
The real killer is concrete production, as the cooking off of CO2 to create portland cement is actually one of the major sources of CO2 in America. Again, capture and reprocessing becomes possible with the availability of cheap power, though I personally think alternatives to traditional cement need to be found.
In any case, abundant energy at low prices derived from an "assembly line" 6th generation walk-away safe nuclear reactor would solve pretty much every one of the problems out there when it comes to carbon emissions and energy. And that merely assumes fission. With Lockheed supposedly producing a "semi-truck sized" fusion 100MW fusion plant that could be parked next to any major factory, the game changes even more.
Life, the Universe, and Everything... in my image.
The absolute best batteries available today are around 1.8 MJ/kg in storage. Compare that with jet fuel which is around 43 MJ/kg. Now cut the range your airplane can fly by a factor of (43/1.8) ~24 and you'll see the issue.
That is not a fair comparison. A battery can convert 95% of its energy to thrust. The best turbofan jets can reach about 36%. So ((43 * 0.36)/(1.8 * 0.95)) = ~ 9.
But that isn't fair either, because when you burn fuel you are no longer carrying the fuel, so the plane gets lighter and uses less fuel per mile further into the journey. The weight of a battery doesn't change. The batteries are deadweight during landing, making landings more dangerous and requiring longer runways.
Batteries need to improve by a roughly a factor of ten to be competitive for long haul aviation. That is unlikely.
A compromise may be to use electrical energy for the takeoff, possibly with a mass driver with the batteries on the ground. This means smaller, quieter, and safer jets (since they don't have to be beefed up for takeoff thrust) as well as shorter runways.