GM Wants to Make Each Cylinder a Generator with New Patent Application by Sebastien Bell November 29, 2019 Share Comments General Motors’ latest patent application aims to turn each of your cylinders into a generator. By placing a magnet in your piston and adding a coil of wire around the cylinder wall, each piston could generate electrical–as well as mechanical–energy. The idea is simple enough, though, as any Juggalo will tell you, magnets complicate things. When a circle of wire surrounds a magnetic field, moving that magnetic field creates a voltage. It’s exactly the type of generation that powers those wanky flashlights you probably have in your emergency preparedness kit. By strapping a magnet to the piston, it moves up and down through the wires, generating power. That power can be sent to a battery and stored in much the same way as regenerative braking. Contained within that analogy, though, is the reality that there’s a cost to generating electricity. Thanks to an irritating little law called Lenz’s the wires slow the magnet moving through them down. This would express itself as slowing down your piston, sapping your power. But there’s no such thing as a free lunch, so any way you try to generate electricity will lead to some parasitic loss and it may be that GM has determined that the benefits outway the costs. There are also some advantages to the hybrid engine. Namely that you could move the cylinders by feeding electricity back into the coils. That means you could potentially start the engine more smoothly, which would be nice in a car with a hybrid powertrain. The electricity generated can also be used to power a heater to warm up the engine (or the electric motor) faster in the cold. Another nice benefit of the system is that it can (relatively) easily be retrofitted onto an engine. The wires are contained within a ceramic cylinder liner and a new piston head with a permanent magnet in it just needs to be swapped in for the traditional ones. Naturally, you still need computers and the like to run it so this isn’t necessarily a replacement for the alternator in your Chevelle, but the simplicity of the system at least means that GM doesn’t need to design a whole engine line to accommodate the system, which should help keep costs down.