Germany's requirements for a stable, renewables grid

Against a backdrop of negotiations between the major German political parties to forge a grand coalition federal government, the debate over the future of the country’s grid has taken centre stage at the 14th Forum Solarpraxis conference in Berlin.

As an increasing share of renewables, including PV, is added to the electricity network, the role of renewable energy installations in the grid is continuing to be discussed. Costs, due to grid expansions some argue are necessary to sustain renewable capacity expansion, are presented in sections of the German media as an argument against the growth of renewable energy.

However at the Forum Solarpraxis, which concludes in Berlin today, an alternative role for PV and renewables has been presented.

David Wortmann, from solar developer Belectric, made the case the "reactive power" capability of solar installations should play a major role in stabilising the grid. "In the political space we don’t see enough support for reactive power," said Wortmann, "it’s not understood by politicians." Belectric says the large inverters in solar power plants could play an important role in stabilising the grid, even when solar plants are not producing at peak levels.

‘We need to effect a change’

In terms of the frustration felt by firms such as Belectric regarding the potential for reactive power provision, Wortmann did not pull any punches: "You can despair at this, somehow we need to effect a change," he added. He also made the case for renewable energy installations to be built more strategically, to limit the need for vast grid expansion. "It’s not only the grid network that needs to be considered," said Wortmann, "we also need to consider the location of renewable energy installations. Why build offshore wind and absorb the grid costs, that could be billions, when we can integrate a decentralised renewable energy system?"

Addressing the reactive power potential of PV, Barbie Kornelia Haller, from the German grid regulator, said the agency does recognise the potential for PV and wind installations to provide such a service, but there is no political framework in place as yet, to do so.

"To establish a reactive power market, this needs to regulated by legislation," said Kornelia Haller, "many players are currently having discussions regarding this." She added distributed storage could also play a role, including for voltage regulation on a grid level.

The need for grids to deliver better information about supply and demand was also addressed at the Solarpraxis Forum.

Claudia Kemfert, from the German Ministry of Industry, said there are various smart grid programs in Germany and solutions emerging from them can be integrated.

"We need to look at best practice with smart grids being expanded in a decentralised fashion," said Kemfert, "we might be able to pool the best solutions."

The formation of a coalition government, anticipated within days, is expected to lead to more details on the future of German grid expansion and the regulations underpinning renewable energy, the EEG. It is to be hoped renewables policy is not a sacrificial victim of the horse trading going on between parties.