Onshore wind power is the wunderkind of Germany's path-breaking clean energy transition. Stretching from the gusty coasts of the North and Baltic Seas all the way now to the Alps, the nation's land-based wind turbines (23,000 as of 2012) account for virtually all of Germany's 30-plus GW of wind-generated green electrical capacity. This generates nearly 40 percent of the country's entire carbon-free electricity production, roughly equal to 40 nuclear reactors. By expanding its supply ten-fold since 1998, it has exceeded the rosiest forecasts of green-thinking optimists -- and costs have plummeted, too. It is no exaggeration to say that onshore wind has turbocharged Germany's Energiewende, the epic transition of Europe's foremost industrial heavyweight to an all-renewable power supply.

Indeed, without the punch of onshore wind Germany would never have shattered the records it did in 2011 and then again in 2012: 22% of Germany’s electricity supply now stems from renewables. On sunny and windy days, onshore wind and photovoltaic meet over 85 percent of Germany’s mid-day electricity needs. Rather than importing nuclear-generated power from its unapologetically pro-atomic neighbors since Germany shut down a third of its reactors in spring 2011, it exports electricity to France – and indeed sold more abroad in 2012 (23 gigawatts) than ever before. Germany’s renewables industries provide now 386,000 domestic jobs, over a third of those in the onshore wind sector. These are the kinds of acolytes that, despite rising energy costs, secures the Energiewende broad and consistent popular support. A recent independent poll showed 93 percent of Germans solidly behind the clean energy switch.        

“It’s clear now that onshore wind and PV will be the backbone of Germany’s energy supply, with the rest of the power system being optimized around them,” explains Rainer Baake, director of the Berlin-based NGO Agora Energiewende. (Solar power production has also dwarfed projections of just a few years ago, hitting a record high last year by adding more than 7.6 gigawatts of capacity to Germany’s power supply, thus boosting supply in 2012 to over 28 gigawatts, a jump of 51 percent over 2011.) Baake argues that by 2015 the total cost for power produced by wind and photovoltaic plants will be roughly 7–10 euro cents per kilowatt hour, thus about the same as electricity generated by new gas and coal powered plants. 

“In 2000 a competition was opened up to the whole array of renewables,” Baake says, referring to landmark legislation that provided green energy – from wind to geothermal – with feed-in priority to the energy mix and compensation for high investment costs in the form of high-than-market-price tariffs. “And we can now say that onshore wind and PV have won it. No other renewable energies can generate electricity in sufficient quantity at such low costs. Wind and PV are the most essential pillars of the Energiewende,” explains Baake, who was a high-ranking official in the 1998-2005 center-left government responsible for the seminal clean energy laws.

But even in energy-progressive Germany, this conclusion – that two such weather-dependent sources as onshore wind and PV can supply the needs of German industry and heat homes through frosty winters – is fighting an uphill battle for acceptance, not least in the current administration of Chancellor Angela Merkel. Moreover, although there are convincing arguments that onshore wind could do significantly more than currently projected by official sources, this is a proposition with opponents far beyond the NIMBY movement. Germany’s center-right government says it want to “slow down” the Energiewende, which it claims has been too successful for Germany’s own good. After scaling back photovoltaic’s feed-in incentive last year, onshore wind, the undisputed prize pupil, is now also at the heart of this simmering conflict in election year 2013.     

Among the current scenarios for the transformation of Germany’s energy mix  there are vastly diverging prognoses for onshore wind’s role. In all, green energy will provide at least 40 percent of Germany’s electricity supply by 2020, according to a recent government update reflecting the expanded output of onshore and PV. But how much of this will be onshore wind? The government’s official 2010 energy concept pegs onshore wind to account for 36 gigawatts of installed capacity in 2020, a low-ball, now outdated figure that has been overtaken by burgeoning supply. The German Renewable Energy Federation (BEE), an umbrella organization of renewable energy associations, has onshore ramping up by half by 2020 to 45 gigawatts a year and then, together with offshore, providing a full half of Germany’s electricity by 2050. Other more bullish scenarios, such as one prepared by Germany’s 16 federal states, or Länder, predicts that onshore could account for as much as 86 gigawatts by 2023. 

“The government’s numbers, even the newest ones, are very conservative,” says Andree Böhling of Greenpeace Germany. “The figure of the Länder, though, is most probably too high, possible only if all the chips fall in place.” Greenpeace wants to shoot for 50 gigawatts of onshore by 2023 and a 45 percent share of renewable electricity in Germany’s power supply in 2020. “This is doable,” says Böhling, who adds that increased onshore capacity in the south would obviate the need for expensive new transmission grids planned to bring on and offshore supply from Germany’s north to its industrial south. 

“We can reasonably expect that a combination of repowering in the north and new [onshore wind] parks in southern Germany will contribute about 2 GW [of installed capacity] a year for the foreseeable future,” explains Rainer Hinrich-Rahlwes, a former environment ministry official and currently BEE board member. Even though the furious pace of onshore wind’s expansion has slowed since the late 2000s, Hinrich-Rahlwes argues that this steady, powerful contribution its annual growth is nevertheless extremely impressive – as well as unrivaled in terms of bang for the buck compared to other renewables. He also says that onshore has a lot more potential than government officials are currently willing to acknowledge, depending, he underscores, on the policies toward renewable energy that Germany settles upon – most probably after the national elections in autumn this year, which Merkel’s poll-leading conservatives are likely to dominate.

There are others in-the-know who put the case for more onshore even more bluntly. The renowned Fraunhofer Institute, one of the world’s leading applied clean-energy research institutes, estimates that if 2 percent of Germany’s available landscape were approved for wind park development, the capacity could supply Germany with a full two-thirds of its electricity needs (198 gigawatts of capacity).