In the wake of the government policy decision to pull the plug on nuclear, Germany has ramped up its renewables drive, but this has been hampered by delays in work to boost the country’s transmission and distribution network.
However, the new research – conducted by renewables consultancy Ecofys and the Smart Energy for Europe Platform (SEFEP) – concludes that “even without any grid expansion by 2020, Germany can still deploy significant renewable electricity sources within 15 years”.
The report’s authors say that they have debunked “two persistent myths regarding the Energiewende: the first that if Germany’s grid expansion plans are delayed, a slowdown in renewable energy investment will happen in the coming years, and the second that wind should be built where it’s windy, and solar should be built where it’s sunny”.
The study found that Germany can still meet its target of getting 72 per cent of its energy from renewable sources by 2030 even if grid expansion is limited to projects that were already under construction by December 2012.
And it adds that the costs of this limited grid expansion would be manageable: “System costs would only increase by 0.8 to 3 per cent depending on the geographical distribution and generation profile of the nation’s renewable energy sources.”
Christian Nabe, electricity market specialist at Ecofys, said: “If grid expansion is delayed, about €800 million in transmission costs can be saved per year if we spread wind and photovoltaic installations more evenly across the country.”
The study concludes that increased amounts of PV and onshore wind, with a decreased share of offshore wind, would create a system that was more robust against grid expansion delays.
“If more offshore wind is added, then grid expansion becomes more urgent as, for example, offshore wind power generated in the northern part of the country needs to be transported to southern population centres,” staes the report.
It adds that replacing 10 GW of offshore wind with solar PV and onshore wind would not disadvantage the total system cost, create more emissions or require increased curtailment.
Ecofys said that “system flexibility will also be key to Germany’s energy future”.
It said if “grid expansion as a source of flexibility is limited, other options such as compressed air energy storage and load shifting will be the most cost-effective means”. The report dismissed battery storage as not being “a cost-optimal technology”.
The report also says that the “myth that wind should be built where it’s windy, and solar should be built where it’s sunny” is “simplistic”.
“It reduces the complexities of the Energiewende to a question of wind and solar resources. But other economic and non-economic factors also need to be considered, including the costs of land, capital and project development, the availability of skilled labour, policy certainty, social acceptance, the need for regional and national self-sufficiency and regional development concerns.”
The study also claims that if Germany delayed its grid expansion, it could result in slightly lower CO2 emissions in 2030, compared to full grid expansion.
“This is because grid expansion creates favourable conditions not only for the integration of wind and solar, but also for the steady operation of inflexible, low marginal cost power plants such as those that burn lignite.”
It added that in all scenarios modelled by the report authors, 2030 emissions are reduced to about one third of 2011 levels due to an increasing shares of renewables in the mix.
However, the authors cautioned that their results “should not be interpreted to mean that grid expansion is not important for the Energiewende”.
“Grid expansion will increase the stability and resilience of the Germany’s power system and reduce the costs associated with ancillary services and a strong grid is a good investment toward the expansion of renewables over the coming decades,” they said.
Raffaele Piria, SEFEP’s programme director, said: “The study shows that rapid expansion of renewable energies can continue. If grid expansion is delayed, we need to manage geographical distribution of renewables wisely. With rapid grid expansion, effective measures to reduce emissions from lignite become even more important.”