Apparently on date 3 Apr 2004 23:28:41 GMT, "Michael R N Dolbear"
said:

Sales! wrote
[...]
was generally seen as *the* future solution then. Fusion has been on
the
horizen for a long time. I wonder if it will ever deliver?

It's been delivering for about four billion years, why would you
doubt it
works?

The problem with * that * fusion reactor is that it can't be switched
off, can't be refueled and will explode as a nova when the fuel runs
low.

It would never pass Greenpeace's checks, sorry.

The sun isn't really the same thing as a fusion plant, though, no fusion plant
will weigh the same as a million planets so the issues of it going nova don't
apply, it will never be a gigantic object with so much mass it implodes into a
gravity well, once the fusion no longer prevents this.

Similar logic, you can refuel the sun and you can switch it on and off, by
adding or removing various constituent parts, e.g. suck the helium out of the
core and the sun can carry on for another four billion years without
maintenance. Remove enough hydrogen, and the sun stops being massive enough to
initiate fusion by gravity pressures alone.

The real reason fusion plants don't exist, is because they don't know yet how
to make them produce more energy than it costs to make them work. This is a
practical barrier as the sun is a working demonstration that the theory is
fine, and the fusion process does work in the lab. Just, you have to have it
show you a profit or there's no point in doing it in the first place.