A windmill could spin until it falls apart and never generate as much energy as was invested in building it.
No, a professor didn't say a windmill will 'never generate' the energy invested in building it [...] Now, we have a meme roaming social media that claims Canadian author and professor Thomas Homer-Dixon said that windmills will "never" generate as much energy as was expended to build the structures. [...] The meme does get a part of the quote right, but it strategically leaves out large swaths of information in order to give people the impression that all windmills never expend the amount of energy that was invested in it, which is not accurate. The meme’s omitted section explains that, while poorly placed windmills may never generate enough energy payback, a good wind site could generate it in three years or less.