That applies in particular to the timing of the shutdown of the country's nine remaining nuclear reactors and the construction of replacement generating capacity, he told Deutschlandfunk radio.
That will help ensure stable energy provision and reduce the risk of sharp price hikes for consumers, he said.
Berlin permanently shut eight nuclear power plants after the Fukushima nuclear disaster in Japan in March.
Germany's parliament is scheduled on Thursday to ratify a programme to close the remaining nine in stages over the next 11 years.
Energy policy mix was a matter for each EU state to decide for itself, and the EU completely accepted Germany's shift away from nuclear power, Oettinger said.
Germany's planned exit from nuclear power has surprised its European partners and raised concerns about the impact this will have on other countries that import German electricity.
BusinessEurope, an employers' group, sent a letter to Oettinger on 10 June, demanding an EU impact assessment into the phase-out's likely effect on costs.
The group cited a study by the German Federation of Industries which found that a nuclear phase-out by 2017 would increase energy bills, possibly across European borders.
Nuclear plants supply 25% of German electricity, forcing operators to find alternative sources of power. Importing nuclear, gas and coal from its neighbours might end up being the easiest option, according to William C. Ramsay, deputy executive director of the International Energy Agency (IEA).
EurActiv with Reuters