Enercon's installations totalled 1.38GW, all onshore. The company's share in the onshore market alone was 37.3%, according to figures from German-headquartered wind research institute DEWI.
In 2014, Enercon held a 43.1% share of the German onshore market. Its totalled installed capacity in 2015 was also lower compared to a year earlier when it installed more than 2GW.
The fall in Enercon's share contrasts sharply against 2013's total, when the manufacturer held a 49.5% share in onshore installations.
Siemens took second place in 2015 with 25.6% in the overall wind market, due to its dominance in the German offshore sector. Siemens' turbines accounted for all 1.2GW commissioned at sea in 2015.
On land, Siemens barely made a mark in its home market, with just 1.7% or 63MW of the total 3.7GW installed onshore.
In Germany's combined (onshore and offshore) wind market, Vestas accounted for 16.1% or 788MW of new capacity installed last year.
Senvion, Nordex and GE had shares in the combined market of 13.6%, 8.9% and 5.5% respectively.
Germany now has more than 45GW over installed wind capacity up from 40.45GW installed at the end of 2014.