Rapture_Tales
Instead of Source power, everybody uses Backup Power. Although, in this particular context Source Power would most likely refer to a sci-fi gizmo power source and not for instance a huge diesel generator (diesel generators are completely immune to EMP, especially if they were started before said EMP was fired, since diesel engine doesn't rely on electricity or electronic control to run)
Just because satellites lose power they would do nothing out of the ordinary, unless additional forces are transmitted to them. They will keep either moving or "standing still" depending on their orbit without colliding with anything, since their movement follows predetermined orbits that don't require additional energy expenditure. Satellites are basically big lumps of metal that were accelerated to a speed where they remain on orbit while they were deployed.