How much energy is use to make a domestic wind generator, in comparison to the power it gives out .?

The energy return on investment (EROI) for wind energy is equal to the cumulative electricity generated divided by the cumulative primary energy required to build and maintain a turbine. The EROI for wind ranges from 5 to 35, with an average of around 18. This places wind energy in a favorable position relative to conventional power generation technologies in terms of EROI. Baseload coal-fired power generation has an EROI between 5 and 10:1. Nuclear power is probably no greater than 5:1, although there is considerable debate regarding how to calculate its EROI. The EROI for hydropower probably exceeds 10, but in most places in the world the most favorable sites have been developed. Therefore to answer your question directly it would depend on the use and siting of the generator predominently as the range of 5:1 to 35:1 is quite wide.

I don't know the answer either but it is an excellent question and one that the"environmentalists" should study carefully. They really don't know either and they always go on the "if it looks green it is green" idea. The answer cannot be "never" as this means that the capital cost would also be far greater than the total energy output during its lifetime.

Don't know the figures but I heard (depressingly) that you never overcome the energy spent on its manufacture. Same with railway carriages.