Seems like generating power to feed to a heat pump would still be more efficient, despite electrical losses, considering that good heat pumps can be 3x more efficient than friction/resistive heating.
One of the main benefits of the water brake system is the storage of heat. With a sufficiently large insulated tank, you can retain head for days to weeks when the wind subsides. The water brake gives you a little more insurance compared to electricity generation for an off-grid solution.
The problem is wind can be unreliable. With a electrical system you are way more flexible.You can use the generated electricity if you don’t need heat and if you are in the winter in a period without much wind you can fall back on solar or grid.
Unless you live in an area with very steady wind during the winter and a more or less equal need for heat all year around, the electrical solution is more practical even if it is less efficient.
I could imagine this for warm water with a different system used for heating or something like that.
