Windfair.net interview: Silvio Konrad and Alexander Ohff / TÜV NORD

The energy crisis has once again highlighted the need for a rapid expansion of renewable energy plants. A major problem at present is the shortage of skilled workers. How can we deal with this?

Konrad: Working in the field of renewable energies is generally popular, but in recent years the constant ups and downs due to regulatory interventions have led to many skilled workers migrating to other countries and regions or to other industries. Now, with the strong expansion coming, we have a huge shortage of skilled workers. The most important thing now is to have a stable regulatory framework and a "skilled labor recovery initiative" to be able to offer an attractive and secure working environment in the long term.

Ohff: At TÜV NORD, we have been growing steadily for years and rely on continuity because we operate internationally and diversify into different markets. From my point of view the most important thing is the day-to-day working environment: we rely on a culture with friendly interaction, open and transparent. We want our people to enjoy coming to work and spending time with their colleagues.

In Germany more and more hybrid plants have been built in recent years, in which different types of RE plants are combined with storage systems. What are the technical challenges with these plants?

Konrad: Already during the planning of a hybrid park, the components should be coordinated. The output of the energy generation plants must match the capacity and output of the energy storage systems, and the different voltage and current levels must be interconnected. In addition, there is usually a sophisticated, largely automated operation management system: this regulates, for example, at what time the storage system is charged so that enough energy is available for the next lull. This is the only way to ensure security of supply! Here economic considerations meet "natural" conditions, functional safety requirements and protection of the plants against cyber attacks.

In recent months, hydrogen has become the much-cited savior, but most projects are still in their infancy. Is the potential for this technology really that great, and how long will it take for the hydrogen boom to really take off?

Konrad: The demand for hydrogen in Germany will rise sharply; current forecasts predict that by 2045 it will be equivalent to one third of today's natural gas consumption. However, we often lose sight of the fact that not only production or import must be ensured, but also suitable transport infrastructures and storage capacities. In all three areas, we are working on promising pilot projects to enable both uniform and sustainable international certification. The European Commission should create an investment-friendly framework for the necessary market ramp-up with the Delegated Act now pending. Likewise, an instrument comparable to H2Global should be established at European level with appropriate funding.

To date, there are nearly 30,000 wind turbines installed in Germany with many of them getting on in years. How can we ensure that they continue to operate safely beyond their intended lifetime?

Ohff: For lifetime extension, we analytically check what loads the turbine has been exposed to at precisely this location and thoroughly inspect its condition on site. On this basis, we make recommendations on how to ensure safe continued operation. Repowering can also play an important role: The old turbines are often located at wind-strong sites that should be used as efficiently as possible to achieve the expansion targets which are very ambitious, for example, in Germany.

In the course of the energy transition, the need for offshore wind farms will further increase. What are the challenges from a technical point of view and how can they be met?

Ohff: The biggest challenge in the offshore sector is the low flexibility of the supply chain, as there are only a few specialized suppliers for the construction of offshore wind turbines, foundations or transformer platforms. If offshore expansion picks up, I also see a bottleneck in the availability of suitable specialized installation vessels. For the large 15 MW+ offshore turbines, new jack-up platforms and crane vessels are needed as the transport and lifting capacities of the existing vessels are not sufficient. Delays can also occur in the balance of plant, such as substation platforms or cables, when multiple projects are installed simultaneously and they compete for the few specialized suppliers. The offshore supply chain requires a fair amount of specialized knowledge, so continuous utilization is essential for a sustainable and healthy development of this exciting market.