I am not certain as to the energy required for manufacture, but it would be difficult to believe it would equal the power that could be produced in turbine use. Take for example a 1" by 2" by .5" magnet on a 10 foot dual rotor turbine. If the magnet lasts for 10 years (all other repairs aside) then if the average output over the life of the turbine was just 25 watts, which should be incredibly low. Then the watt hours produced would be equal to 25 watts times 24 hours per day times 365 days per year, times 10 years, or 2,190,000 watt hours. For each of the 24 magnets used this would then be 91.25Kwh.
I also find it difficult to believe that all things considered, my old vintage 1980's Arco panels took more energy to make than they have produced. They still output about 1.86 amps at about 16 volts, or about 30 Watts. Now they are more than 20 years old, probably about 25. I don't know their exact history before I got them, or what percentage survived to this ripe old age. For these panels, if they've been toiling in the sun for an average of 3 sun hours a day for 25 years or so, then they should have produced a large amount of energy by now. 30 Watts times 3 hours times 365 days times 25 years equals about 821Kwh of energy. If half of the panels failed up to this point that is still over 410Kwh of energy. I don't know how much energy it took to make them, but it seems difficult for me to believe that it could have taken nearly that much energy per panel. Rich