* Networks need reserve options as some nuclear power is missing
* Some 2,500 MW of extra capacity needed again, of which 2,000 MW is contracted
* Regulator worried by unclear longer term scenarios
MUNICH, Sept 10 (Reuters) - Germany can secure enough emergency electricity capacity to get through the winter, should there be tight supply on transmission networks, its energy regulator on Tuesday.
"The situation is tight but under control, there will not be black-outs," Jochen Homann, president of the Bundesnetzagentur told an energy conference in Munich, days before his Sept. 15 deadline for reporting back to government on the situation.
The problem of potential energy shortages will remain for years as nuclear plants in southern Germany are closed quicker than grids are revamped, Homann said. In the 2012/2013 season, Germany's power network came under pressure once in late March.
The regulator took 2,500 megawatts (MW) in capacity reserve under contract last winter to ensure steady power supply, a task made more difficult since Germany in the summer of 2011 shut 40 percent of its nuclear plants.
Homann said that transmission system companies (TSOs) that he supervises had already secured broadly 2,000 MW and that solutions for the other 500 MW "would be found in the coming weeks, if needs be via auctions."
A planned revival of a closed E.ON coal-to-power block Staudinger 1 near Frankfurt fell through as the closure turned out to be too far advanced to be reversed before the winter.
Utilities are phasing out power plants in a depressed market - some 15 sites have applied to close. Homann's authority has to approve the plans under laws safeguarding supply security.
Most of these would not affect the stability of the overall power grid but this could change in 2015, when E.ON's Grafenrheinfeld nuclear plant is to shut in the industrial south, where power demand is highest, he said.
Homann also said he was concerned about the increase of network interventions that grid managers had reported - these stress cables and lines and raise the risk of local disruptions.
Hours in which such activities were necessary rose to 7,200 hours a year in 2012 from 5,000 in 2011 and 1,800 in 2010, he said.
"I don't think this figure will be going down," he added. (Reporting Vera Eckert and Jens Hack, editing by William Hardy)