Scenario:

* Earth men colonized Alpha Centauri.
* Barnard's Star is at range.
* There is a huge fleet of fission bomb pulse propulsion cargo ships. Given Enough time and space they can reach 0.8C.

Question:

Barnard's Star has no planets to colonize. Would it be possible to use it to collect energy? If so, how? How could they send energy back to Earth? What about to Alpha Centauri?