I'll avoid putting this in EE :-) Taking power from cars while they are braking may make sense. But, anything that generates power from a car's slipstream on a level motorway is liable to be a bad idea overall. This man doesn't think so: > http://www.metropolismag.com/cda/story.php?artid=2466 Darrieus wind turbines mounted on the centre line use the 'wind' from passing cars to generate electricity. That's one way to get fuel to power your alternators. But it's unlikely to be an energy efficient or ecologically viable one. IMHO anyway :-) Russell ref: Matthew McMahon FWIW - the article refers to Darius (sic) wind turbines. Can't say I've heard of that version :-) -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist