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

Question

How long would it have to run before the energy it produces would exeed the initial energy expended in its manufacture

Answer 1

A good way to estimate is that it takes about 300 kwh of electricity per pound of metal (aluminum) to create device.
So let's use 1MWH per pound for overall system as a conservative estimator.

If your 5 killowatt wind turbine system weighs 400 lbs in total, then it needs to generate 400MWH of electricity in its life to "break even". If you get 2000 hours per year of full rated output, that is 10MWH - so it would "break even" in about 40 yeas of use.

If you managed to lower the manufactured weight of the system to 100 lbs, it would pay back in ten years or less. You would also do better if more of the system were made of plastic rather than metals.

Hope this helps!
OC

Answer 2

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.

Answer 3

I've wondered the same things, and heard similar answers.
If you were to build a wind farm and use its energy in the production of other wind generator equipment, how would it affect the overall equation? The new equipment would have been built from green energy.

Answer 4

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.

Answer 5

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