A Savonius wind turbine is the simplest form of vertical wind turbine you’re likely to see. At their most basic, they’re made from two halves of a cylinder cut lengthwise and stuck back together around a rotating axis. They’re easy to build, but not as efficient as some other designs – which is why Adrian Cubas has created his own design here, adding wind deflectors to improve torque and reduce drag on the side of the cylinder that’s moving toward the wind.

Adrian used a stepper motor in place of a generator – it’s basically just wires and magnets, and so the only consideration, if you’re going to make one of these yourself, is that you really need to wire the thing up correctly. The central part of this turbine is made, as so many are, from a length of PVC pipe; the rest (the clever bits) Adrian cut out using a CNC, a jig‑saw, and an angle grinder.