San Francisco Chronicle: As dark clouds approached, Guillaume Craig packed up his tools, climbed into a rickety boat and sped off from a small fishing village, hoping to make the three-hour commute downriver before nightfall. The boat wasn’t quite fast enough, so the former Oakland resident used a flashlight to guide his way back through endless miles of tropical forest. "That was actually our easiest site to reach," said Craig, whose San Francisco-based Blue Energy foundation is delivering …