[blisterpeanuts]

>>>...by then we will be all on renewables plus cheap storage, or at least pretty close. What would the incentive be for ripping that all out and replacing it with immensely costly fusion plants?

That's a valid concern. Probably in 37 years, we'll all be riding in self-driving electric buggies that recharge in 10 minutes from stored solar power.

Lockheed-Martin[1] is working on a compact fusion design that some day might fit on a truck yet power a city. It might keep a C-130 plane aloft for a year, or keep an aircraft carrier at sea for multiple years. It might power a spacecraft to Mars, shortening the trip from six months to one month.

There is a need for a compact, concentrated, continuously generating power plant at least for these kinds of specialized applications. Whether it will still make financial sense by the time it's actually working is another question. Perhaps the main use case will be military, though the idea of an airship that can stay aloft for months or years is rather appealing -- given enough power, you could put a city in the sky.

1. http://www.lockheedmartin.com/us/products/compact-fusion.htm...

[grkvlt]

From that LockMart page on their compact fusion reactor:

> ENERGY CREATED THROUGH FUSION IS 3-4 TIMES MORE POWERFUL THAN THE ENERGY RELEASED BY FISSION

I'm not entirely sure how to parse that...?