Duke Leto wrote: No, zapkitty’s right. The current Desal process is obviously too equipment intensive by comparison to just boil and coalesce. If he’s right then 50 cents might not be unrealistic.

Then and again I’m barking mad.

You ARE mad… it would be much cheaper 😉

The following calculations are BotE, don’t count plant costs (but those will be dirt cheap compared to current desal gear) and assume 100% efficiency in applying the FF heat to the water… but this will still get you within an order of magnitude or two of the cost:

amount water at 20 degrees c (kg) 1000
(1 metric ton seawater)

spec heat water (kj/kg) 4.186
latent heat (kj/kg) 2260
delta t (c) 80

1st step raise to 100c (kj) 334880
2nd step vaporize (kj) 2260000
total (kj) 2594880

FF kilowatts thermal (kwt) 7000

process time (sec) 370.7
process time (min) 6.18

Yep, even the waste heat from a 5 MWe fusion reactor takes over 6 minutes to boil away one ton of water.

daily water output (tons) 233.07

kwh in a day 24
FF elec cost kwh (cents) 0.2
desal power cost per day (cents)… 4.8

power cost 1 ton water (cents) 0.021

Lerner-hakase has it right… FF fusion desal makes water problems simply go away.