Nordex will replace the 16 N60 1.3MW turbines with nine N117 3MW turbines for the PNE Wind-owned project by the end of 2016, the manufacturer said.
"In Germany, it is important to increase the output of existing wind farms and to simultaneously reduce the number of wind turbines," said Nordex's Germany managing director Jorg Hempel.
As well as increasing capacity, Nordex said updating the turbines would result in more full-load hours, improved grid compatibility and lower rotor speeds and noise emissions.
The N60 turbines were installed at Altenbruch I in 1998. Work has already begun on dismantling the old turbines and the addition of new access roads on the site, PNE Wind said.
New foundations, larger foundations will also be installed, with upgraded power cables to be laid, PNE said.