Logo of the Helmholtz-Institute Erlangen-Nürnberg for Rebewable Energies
<a href="//commons.wikimedia.org/wiki/User:Helmholtz-Institut_Erlangen-N%C3%BCrnberg_(HI_ERN)" title="User:Helmholtz-Institut Erlangen-Nürnberg (HI ERN)">Helmholtz-Institut Erlangen-Nürnberg (HI ERN)</a>
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<span class="int-own-work" lang="en">Own work</span>