Comment by vintagedave

> and the same power it would take to boil eight kettles.

Newspaper-style units, but laughter aside, I tried to do the math.

If a kettle is rated at 2.5kW, then five minutes of usage (to boil a kettle, or for eight of them do a turn of the bridge) is 2.5kWh * (5/60) * 8 = 1.6kW.

My Nissan Leaf stores about 24kWh. So it's about 7% of a Leaf's battery to turn the wheel, or 10km of range. Given mass, perhaps it is finely balanced, and that seems more reasonable than I expected.

I am not an electricity expert and will get things mixed up ;)