Though wind power is now cheap enough to be economic, and its technical feasibility has been demonstrated to produce the equivalent energy generation capacity of a power station, still requires hundreds of very large machines or even thousands of smaller ones. One remaining uncertainty concerns the environmental impact of this and the resulting public attitudes. Large machines, which could be up to 125 metres in height, can be visible for miles, and must be spread out. Relatively large land areas are required. In addition, the machines emit noise and safety considerations preclude siting them in built up areas. Shadow effects might intrude upon habitations, and there could be effects on birdlife. Wind energy will therefore be highly conspicuous and the final constraint on the amount of wind power installed will be the reaction of the public. This paper reviews some of the relevant factors which make up the environmental impact and then addresses the question of wind farm siting to cause the least impact in the UK.