The windmill was used to pump seawater into the salt pans and the heat to evaporate the water to leave the salt behind was provided by the plentiful supplies of coal, locally.

Maybe calling it a “wind-powered water pump” might be a little more accurate but of course it's not nearly as evocative or interesting a name.

From the far side - looking westwards - the back door can be seen.

A tighter view.

From further back, looking east.