EnBW is buying the ISP from Danish private equity fund Polaris Private Equity for an undisclosed sum.
The acquisition is still pending approval by the German anti-trust authorities and is expected to be completed in the fourth quarter of 2016.
The move comes amid a trend of consolidation in the wind O&M business. In January, Danish wind OEM Vestas agreed to buy German ISP Availon for €88m ($98.5m),