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by rdl·16y ago·view on hn ↗
The challenge is definitely liquid fuels for transportation, especially aviation. Stationary applications can easily go electric, and conceivably maritime transport could go to electric powered by nuclear or bulky non-hydrocarbon fuels, but aviation is weight and volume limited.

The US Air Force has a goal of qualifying all of their aircraft to fly on biofuels by 2011; they've flown B-52s and other aircraft on 50-100% biofuel mixtures. Currently, most biofuels for aviation use cost several times what petrochemicals cost, but I could definitely see this changing. It's actually pretty easy to get a jet turbine to run on anything, but the difficulty is more with qualifying the entire storage/supply chain to be stable, and stability at temperature extremes. If the Air Force can transition to biofuels, it will be relatively easy for scheduled commercial flights to transition.

Given relatively cheap electricity to input, there are plenty of processes to make liquid hydrocarbon fuels -- algae biodiesel, some forms of intensive agriculture, and CO2 sequestration from the air, as are pointed out in the article. These would be "carbon neutral" in terms of atmospheric CO2 as well.

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Nuclear-powered maritime transport been a solved problem for decades. (It's a fairly easy solution, too. Conventional steamships have boilers which generate steam from seawater, which through a significant amount of gearing turns the ship's propeller, and through a turbine-generator system generates the ship's electricity. Nuclear powered ships replace the boiler with a nuclear reactor, but are otherwise identical.)

The only reason not all US Navy ships are nuclear is because you can get better performance for frequently-resupplied, less-than-supercarrier-size vessels with gas turbine engines (literally off-the-shelf jet engines exhausting underwater). The fuel is even the exact same as aviation fuel, so you only need your resupply ships to carry one type of fuel.

The unsolved issue in nuclear maritime is making it cost effective, including all life-cycle costs. The US actually had a couple commercial transports which were nuclear powered (NS Savannah being the main one, http://en.wikipedia.org/wiki/NS_Savannah) , and the USSR built a few icebreakers and supply vessels, a few of which are still in operation.
Cost-effective is comparative. If there was a severe shortage of other maritime fuel, we'd be stuck between nuke and sail.
True; and according to NS Savannah's reports, it actually would have been viable during the 1970s.

I wonder if there would be a business in either operating nuclear civilian ships, or outsourced reactor build and management. The irony being that some of the best prospects would be nuclear Very Large Crude Carriers.

The other reason the Navy doesn't want 100% nuclear (and kept ships like the Kitty Hawk around) was some countries are weird about nuclear warships specifically transiting their waters; some are anti civilian nuclear too, but are generally more anti-nuclear warship.