Board Thread:Questions and Answers/@comment-1456127-20130226215716/@comment-208.124.75.22-20130227034556

They are part of Industial Craft 2. They run off of EU and can be used to power BuildCraft machines such as quarries. They are nice because you can directly run an EU power source into an electric engine to power a quarry, rather than the old method of having to run an EU power source into an Energy Link to convert it into BuildCraft enegry (MJ) and then into an engine to power a quarry.