[jbert]

> perhaps you could put it into some non-volatile heat sink, but unless it's a really big heatsink, you wouldn't want to be anywhere near that thing when it went into resistor mode

Specific heat capacity of water ~= 4(KJ per Kg per Kelvin)

so, assuming we can safely take water from 20 degC to 90decC, we'd need 21MJ / 4KJ/K/degC / 70degC == 75Kg of water as a heatsink.

Or about the weight of one passenger.

Double or triple up for safety factors (avoid steam) and you're still OK. Have some insulation and drive some A/C to chill the water further and you're also OK.

So yes, dump it into a resistive load immersed in a tank of water?

(Edit, that said I do think that The Right Way to do transport+energy etc is for us to find our correct "limitless" source of energy (fusion or orbital solar, I guess) and turn that into synthetic hydrocarbons as a convenient, relatively safe, energy dense fuel. i.e. we don't build massive supergrids for pushing that power to people over wires. We pump the power into a CO2+H2O=>petrol converter which we then ship around the world using the existing infrastructure. We also don't need to retool the whole world's transport infrastructure. Obviously all carbon-neutral too. (Carbon -ve if you've got the spare power.))

[dmv]

How would systems running on petrol be carbon-neutral? Granted, you reduce one form of carbon emissions by presuming a clean form of energy and petrol generation. Use of the petrol, however, should still result in carbon emissions. Have I missed something?

[jbert]

If you're making the hydrocarbons from CO2 and H2O, you're taking as much CO2 from the air as burning the hydrocarbons will liberate.

Obviously, you need to put in the energy too. But I think synthetic hydrocarbons are a great way to carry around useful energy. They're very energy-dense, should be cleaner than oil from the ground and the whole world is tooled up to use them.

However, they're not useful until we also have:

- loads of power

- an efficient way of turning that power + CO2 + H2O into hydrocarbons