By Vera Eckert
ESSEN, Germany (Reuters) - Weather-driven surges of German solar and wind power may lead to higher costs for Austria as its grid is forced to take measures to avoid breaking down, a Austrian energy regulator said, calling for a region-wide solution to excess flows.
Martin Graf, who shares leadership of the Vienna-based E-Control authority with Walter Boltz, said Austria already must deal with a constant unwanted supply of 2,000 megawatts of power from northern Germany that flows into its grid via Poland and the Czech Republic, he said.
Germany has been slow to build power lines to ensure its growing renewables supply flows to its own market.
"Such load flows go via Poland and the Czech Republic to Austria," Graf said in an interview during the annual E-World energy fair in Essen. "We have a permanent import via the Czechs of 2,000 megawatts."
Austria must then cope with additional surges of thousands of megawatts more into its grid, called loop flows, when the weather favors German wind and solar plants.
Loop flows, which are most acute in the windy autumn and early winter, can knock out transmission systems and cause blackouts.
Austria could theoretically head off the strain on its grid by mobilizing power capacity that it presses in the opposite direction on the grid, but the question is who pays the extra costs, Graf said.
Germany has been in discussions with its neighbors for over two years on the issue.
Czech grid agency CEPS said last month it was in agreement with German counterparts to install phase-shifting transformers by end-2016 to guard against excess power flows. Details of which side would pay for them were not revealed.
The Czech and German grid operators also agreed on the need for wider regional cooperation, which could involve building transformers along the Polish border as well.
These transformers only deflect the flows, which means that the Czechs and Poles could end up moving even more of the excess on to the Austrian grid.
"If Germany and Poland work on deals to remedy this, we may end up being landed with higher costs," Graf said.
BILATERAL NOT GOOD ENOUGH
He said Austria was also in talks with Germany's network regulation authority, the Bundesnetzagentur, about these problems, but he criticized all such bilateral approaches between Germany and the nine surrounding countries.
Loop flows were only one of several issues as Graf made a plea for Germany to rein in the harmful impact on neighboring countries as it shifts from nuclear to green power.
He said Germany is neglecting its neighbors as it considers the idea of building capacity markets, which would reward utilities for keeping gas-fired power stations on standby for operations at times that renewable output is low.
"Again, this is just a national debate in Germany. So how are we supposed to build an integrated European energy market that way?" he asked.
Germany's renewables boom has driven many gas-fired plants out of the market, including some in Austria.
Austria's power market, which is only around a tenth of Germany's 600 terawatt hours a year, is fully aligned with that of its bigger neighbor.
"Austria is offering Germany pumped power storage and huge gas storage possibilities and helps provide system stability on German power grids in the winter," Graf said.
"Therefore, it should be consulted when there are market changes in Germany."
Austria houses the biggest gas storage units in the region where international pipelines converge, which helps prevent seasonal shortages in surrounding countries.
It has held power capacity ready for Germany over the past three winters to cushion systems there after Germany hastily closed 40 percent of its nuclear capacity in 2011 in response to the Fukushima disaster.
(Reporting by Vera Eckert; editing by Jane Baird)