Harvesting the wind

The inland wind turbines of the future

Model of the Bendix wind turbine
Hardly any other topic is currently as hotly debated as that of renewable energies, their fastest possible expansion to more areas, the independence of energy supply from other countries and the fight against climate change. The buzz about wind is giving a boost not least to beventum GmbH, a subsidiary of SPRIND.

The starting point for its foundation in December 2020 was the decades of work on a high-altitude wind turbine by Horst Bendix, a native of Leipzig who for many years had been head of technology and research at the Leipzig-based heavy machinery manufacturer Kirow, as well as a university professor and consultant in engineering matters, an enthusiastic mechanical engineer and inventor. With a total of 60 new and further developments in the field of materials handling technology and heavy engineering, he was successful in international competitions - and launched his heart's project at SPRIND with his submission.
Documents on the wind turbine
Horst Bendix

The higher a wind turbine is installed, the more efficiently it will work, because the wind is much steadier and blows with greater force at altitude. So why not simply build it taller?

Horst Bendix
Initiated by Prof. Bendix, the beventum team, which has now grown to more than ten employees, has been looking into this question. The answer is essentially: No one has dared yet. Until now: In the meantime, beventum has validated three promising concepts - and now wants to attempt to build the world's first high-altitude wind turbine. The young company is currently looking for partners to build the 350-meter-high prototype.

The extra wind at altitude lowers the cost of generating electricity compared to conventional wind turbines in comparable wind zones, so the higher cost of construction is more than worth it. The vision is to integrate these high-altitude wind turbines, which are about twice the height of existing wind turbines, into existing wind farms as a second stage. In addition, high-altitude wind turbines can and should become the most innovative and fastest solution for the economical realignment of the former lignite mining areas. Both the current coalfields in Saxony and North Rhine-Westphalia and the former ones in Saxony-Anhalt and Brandenburg can thus quite realistically become wind energy-based innovation and production regions, and in some cases are themselves already expressing their interest in doing so to beventum. In addition, for the production of "green hydrogen", as planned by the German government, the demand for regional and sustainable electricity will increase significantly.

But beventum is not only aiming high, it has other groundbreaking goals: It wants nothing less than to solve the problem of readily available and acceptable installation sites for onshore wind turbines. As a second focus, the employees are therefore developing medium-height turbines that can be easily built on land that is already in use, such as in industrial parks. Here, too, the conventional wind turbine is being completely rethought. With around 70,000 industrial estates in Germany alone, it is roughly estimated that the installable capacity could be in the order of several power plants, which could be fed directly into the consumers' own power supply.

Another component of the wind energy revolution are small turbines for single- and multi-family homes: radically redesigned with bottom-mounted generator, rotating tower, designed as low-speed turbine with six to twelve rotor blades - and thus much quieter than previous three- to five-meter-high turbines. Simple and easy to install, the mini wind turbine opens up previously unused roof space and optimizes energy generation for self-suppliers.

Ambitious goal: doubling energy from wind power

beventum's main concern is to make installation as uncomplicated and regional as possible - so that as many companies as possible can build their wind turbines and the supply of wind energy finally picks up speed in Germany, Europe and, at best, worldwide. As a SPRIND subsidiary, beventum wants to double the energy from wind power in this country, and to achieve this, it is treading new, courageous paths and also risking failure in the process - but not without stirring up dust and, in sticking with its name, ensuring "bene vento", the good wind.
On December 20, 2022, the official starting signal was given for the world's tallest wind measuring mast on the Klettwitz plateau in southern Brandenburg.

The beventum has assigned GICON®-Großmann Ingenieur Consult GmbH with the wind measurement program. This company is now carrying out a measurement campaign for an assessment of the high-altitude wind potentials. At the same time, a future shortening of the mast measurement durations for this altitude level is to be achieved.

More about beventum: beventum.org

Start of construction in the Oberspreewald-Lausitz district



In Germany, the lack of sites for wind turbines is a strong obstacle to an independent and future-proof energy supply. The concept proposed by Prof. Bendix offers two ways to overcome these obstacles: On the one hand, through wind turbines so large that they can simply harvest the wind above existing wind farms, and on the other hand, through a way as simple as it is resourceful to make wind turbines affordable for all, thus exploiting countless other potential sites outside wind farms. For example, a structural transformation for existing lignite areas is also conceivable.

When adding a second level to existing wind farms, the potential is obvious. With a hub height of 300 meters, we reach heights that have so far remained completely unused and that can be achieved with significantly less approval effort when adding a second level to existing wind farms. The low-cost solution with medium and small wind turbines will become attractive for any industrial area in Germany, whether a wind turbine with a hub height of 20 meters on every backyard or a six-meter-high and very light wind turbine on all flat roofs, which will eventually be as commonplace as solar panels on these roofs.

The goal of the wind energy industry is to constantly optimize technical properties and further increase efficiency. This has brought us a far way. At the same time, we are squandering a lot of potential because we do not look at legal framework conditions or do not consider many regions to be profitable. We deliberately focus on wind turbines that are not technically trimmed for efficiency, but are designed and inexpensive in such a way that they can be placed in backyards and on roofs without too much effort to obtain permits, and ideally a profitability calculation becomes almost obsolete - making wind energy interesting for everyone.
Photos of Horst Bendix
Documents on the wind turbine