there is a way. but it require's build craft.
you take a electrolizer. a hell of a lot of (buildcraft)pipes and watercell's and tresport the watercell to an other electrolizer to take the energie out.
this is the most cheap and fastes way to have a 100% efficiency
EDIT: i sorry didn't read the wiki very well there's a 10% loss indeed.
maybe with battery's?