Repowering Holds Enormous Potential

The story of Willenbacher’s first wind turbine is legendary.

Inspired by the idea of a clean power supply, he began working on the E-40 when he was 26 years old and even risked cutting himself off from his father. “I wanted to take a stand. But when my father learned that the wind turbine costs almost 1 million DM, he was completely against the project; he wanted to save me from making a ‘stupid mistake’,” Willenbacher recalls. His father eventually saw how serious his son was and how quickly he managed to secure financing; he came around and supported his son’s efforts wholeheartedly. It is with pride that he now regards his son, juwi and the Schneebergerhof with its five wind turbines and free-field photovoltaic system which together generate more than 36 million kilowatt hours of clean energy per year. The largest chunk will come from the new Enercon E-126. The power house, hub and the powerful rotors (diameter: 126 meters) are in position at the tip of the 140-meter-high tower, the system delivers enough clean and cheap wind energy to supply a small town. The E-126 generates over 18 million kilowatt hours per year, which is enough for more than 5,000 three-person households.

The E-126 is not the first example of repowering on the Schneebergerhof.

Willenbacher’s pioneer wind turbine, an Enercon E-40 (0.5 megawatt output), was already replaced by an E-66 (1.8 MW) in 2003. The E‑126 (6 MW) is in turn replacing another E-66 (1.5 MW) in the area, which was one of the first of this class when it was installed on the Schneebergerhof in 1997. The site at the edge of the Donnersberg district exemplifies not only the technological leaps that have been made in wind energy, but also the potential of repowering. Hermann Albers, President of the German WindEnergy Assciation (BWE), recognizes an “unbelievable potential for increasing energy yields and the acceptance of wind energy” inrepowering: His credo: sensible and well conceived repowering – that is, powerful wind turbines in good locations – will allow us to generate significantly more clean energy using fewer systems than ever before. Take the example of Rhineland-Palatinate: a study carried out by juwi revealed that by 2030 at the latest, renewable energies could cover 100 per cent of the energy needs in this Federal State. Wind energy is the largest contributor in this equation, generating over 40 per cent of the total. At the moment, its contribution is around 8 per cent, generated by approximately 1,000 wind turbines. “To achieve this enormous increase, the last thing we should do is increase the number of wind turbines. Quite the opposite: with a sensible repowering program, we can in fact halve the number of wind turbines to 500 and still generate many times more power than is currently produced”, Willenbacher explains. If this is true of Rhineland-Palatinate, it is also true of Germany as a whole. There are certainly more than enough good locations for wind power systems – in almost every region. juwi Executive Manager Fred Jung also believes that centralized offshore wind parks far off the coastline simply strengthen the monopoly of energy companies.

With a high feed‑in rate as well as high assembly costs and follow-up costs for expanding the network, for example, offshore wind parks are also a burden to the consumer. “Inland wind energy has been able to compete with conventional power for a long time and still has enormous potential – for regional value creation, above all,” says Jung. “Every wind turbine, solar and bio energy system that produces power on-site is also generating rental and business tax income for the region, so it boosts the economy. This can only function with a decentralized concept.”