.............of course they stand out quite well in the day and shouldn't be a hazard. But, at night, these things can be up to 425 ft AGL without requiring to be lit. Almost worse are the tall, thin masts with guy wires that don't appear on any map which spring up to support data gathering equipment to see if a wind turbine is worth building on the same site - and they don't get lit either. PM me if you are about to low fly in Derbyshire and I'll give you the grid refs of the 4 that I've found.