Mark Kleiman writes:
The Reality-Based Community: Making progress backwards: If you're my age — that is, if your childhood reading included books such as Our Friend the Atom — one of the things you've always known is that all energy problems are transient, since eventually we will learn how to do controlled fusion and the world's oceans will be its fuel supply. In the late 1950s, fusion power was commonly said to be thirty years away. But for decades the horizon seemed to recede as fast as we moved forward; by 1975, fusion was expected to be ready sometime early this century, and by 1990 the schedule had slipped back to something like 2020.
A nuclear engineer of my acquaintance tells me that this is no longer the case. Instead, we're moving backwards. Now no one seriously expects commercial-scale fusion power in the next thirty years. The more we learn about the problem, the harder it gets, and each passing year adds to, rather than subtracting from, our distance from the blessed day when we can thumb our noses at ExxonMobil and the House of Saud.
It seems to be possible that fusion will arrive about the Twelfth of Never.
Nonsense! Mark Kleiman merely needs to look up! (At this time of year, between the hours of 7:30 AM and 6:30 PM.) Gravitational containment of fusion power is very practical, and currently delivers about 175 petawatts of power to the earth.
Turning the energy generated by this gravitational-containment fusion reactor into more useful forms, or starting up another, smaller gravitational-containment reactor at a more convenient place do, however, pose considerable engineering difficulties.