This is an idea to change the models of the machines. At the moment the machines are kind of boring, they're 1 block tall, wide, and long. First off, the solar panels are chunky (that was the inspiration for my suggestion), solar panels are normally sleek and slim. So maybe make them fill 2 blocks (like bed), and have them on an angle, from bottom right to top left of the two blocks.
For some machines you could even have moving parts that would match the IC2 Noises. A macerator could spin, a compressor could have moving parts inside that squash together.
It would be cooler, and look nicer!