You spin me right round: Rotational energy as an alternative to electricity.

I sometimes feel that everyone is a little bit like Harry Ziedler in Moulin Rouge: A bit too excited by electricity. It's not really hard to see why, Electricity makes modern society possible. I'm sitting up in the middle of the night at a desk lit by an electric lamp, heated by an electric space heater, writing on an electric computer. But there's a world of other energy types out there, and I some days we only seem to think of them as things we can turn into electricity.

Most electricity is created via generators. You get some via chemical reactions in batteries and some by solar panels, but by far the most common way to get electricity is to spin a magnet inside a coil of wire. This converts rotational energy into electrical energy. Now oddly enough, run a current through the a similar coil and it will spin a magnet, turning electrical energy into rotational energy with an electric motor. A surprisingly large number of electric devices are just electric motors hooked up to a machine that really only needs rotational energy. Now it totally makes sense to convert the energy to electricity when you need to send it a long distance away; electricity loses very little energy transmitted over long distances, a fairly unique trait as a power source. But when we're talking locally generated power, I'm not so sure it makes sense to convert from spin to electricity back to spin.

When I was growing up, my grandfather had a woodworking shop with a very interesting tool bench. Underneath the table there was a single motor and a drive shaft that ran the length of the table. There were a half a dozen different power tools bolted to the top of the table, but there was only one belt. He would move it up and down the drive shaft and connect it to whatever tool he needed to use. Instead of having a half dozen different electric motors, he only had one. But did he even need that one? My mother has a foot treadle sewing machine. Tapping her feet while sewing spins a wheel that turns the machine's mechanisms. Of course, one must keep tapping to keep the machine working, but that doesn't need to the the case. You can store rotational energy. A Flywheel is a massive wheel on nearly frictionless bearings that spins in place. It's inertia keeps it spinning, and the low friction means you lose little energy over time. Spin it up, and then later have it spin something you need spun. You can even use one as a battery for electricity: Spin it with the motor, hook it to the generator later.

What I propose is this: A drive shaft that runs the length of a house or workshop. This drive shaft is hooked up to a flywheel through a self-adjusting gearbox. Along the length of the drive shaft are a wide variety of tools that are powered by rotational energy. A sewing machine or a band saw are good starts, but so might be a food processor or a water pump. My personal favorite would be a sterling engine hooked up in reverse: a heat pump. spinning it's input causes one end of the machine to heat up, and the other to cool down. You could heat or cool a house this way, or turn it into a stove and fridge at the same time. And yes, you could hook a generator up to it if you wanted, but that's missing the point. The flywheel itself is hooked up to one or more ways of generating rotational energy. A windmill would work where there was wind, a water wheel where a stream, and you can pedal energy in when you need a workout. Maybe even as a last resort, you could get spin from some sort of gas or electric motor. The flywheel acts a storage device and a regulator that ensures that no matter what the spin coming in is like, you get a constant spin out for your machines.

The only part of this that is particularly high-tech is the "frictionless" magnetic bearings for the flywheel, though the better materials you make things out of the more spin you can put on them before they fly apart. The weakness of the system is it's complete non-portability. But it's strength is that it avoids a few unnecessary transitions of energy type. It's also simple to understand and construct, much simpler than many electrical systems. A small kit with instructions and the magnetic bearings, and you could probably fit something together with materials scrounged locally.

And maybe when we are looking at alternate ways to power a machine, we'll take the time to ask "do I really NEED electricity to go this job?" If no, then we can reduce our power consumption by a little bit more, and save that power for the machines that really need it.