What's New in the Windfair World? - The Dutch Windwheel

The Dutch Windwheel is an example of contemporary architecture. The state-of -the-art design consists of two of three-dimensional rings with a light, open steel and glass construction. Because the foundation is underwater, it looks as if Dutch Windwheel is floating.

The double ring construction is not only an eye catcher, but also offers a diversity of functions. The outer ring houses 40 rotating cabins on a rail system (giant coaster), the inner ring is an innovative windmill housing a top class panorama restaurant, sky lobby and hotel, apartments and commercial functions in the plinth.

The proposed location of the Dutch Windwheel is the international port city of Rotterdam. This modern, dynamic and international metropolis is the architectural capital of the Netherlands and continues to renew itself. It adds a unique landmark to the city making the skyline even more spectacular.

Sustainable icon

The Dutch Windwheel will be a showcase and accelerator for innovation, renewable energy and the circular and inclusive economy. It is the dynamic showcase for Dutch Clean Technology and provides a continuous platform to demonstrate technical and technological innovations.

One of the innovations that can be developed with the Dutch Windwheel is the EWICON ( Electrostatic WInd energy CONverter) technology. This technology was developed by a consortium including the TU Delft and Wageningen University in the context of government innovation program. This pioneering wind turbine converts wind energy with a framework of steel tubes into electricity without moving mechanical parts. Result: less wear, lower maintenance costs and no noise or moving shadow. This makes the Dutch Windwheel the most innovative 'windmill' in the world.

Moreover, the Dutch Windwheel is designed for disassembly and re-use and built with materials from the Rotterdam region, the harbour and the surrounding steel industry. With the Dutch Windwheel the Netherlands is an icon with global appeal richer. It tells the story of the Netherlands and generates a new story for the Netherlands; it is both a sustainable icon and icon for sustainability.

Unprecedented attraction

The Dutch Windwheel is one of the most spectacular attractions in the world that can be experienced by everyone. The outer ring houses 40 cabins that run on rails. Visitors from around the world can enjoy an unprecedented view of Rotterdam and the surrounding area from this giant coaster. Visitors look over the largest port in Europe, until the Second Maasvlakte and the sea. From a great height the beautiful architecture of Rotterdam and in the distance the cities of Delft, The Hague and Dordrecht can be seen. The Unesco World Heritage of Kinderdijk glimmers to the east. This unique ensemble of 19 mills from the 18th century, the symbol of the Dutch water management, will be reachable within 25 minutes with the fast ferry. In so doing one not only visits the contemporary Dutch wind icon, but also the icons of the past.

In the 3D rollercoaster interactive cinema a trip through the history of the Dutch water management can be taken. The innovative lighting concept and digital information layer in the cabins of the giant coaster make the Dutch Wind Wheel and it’s interior an experience in itself. Parts of the facade are so-called ‘smart walls’, glass panels that include a virtual layer of information that give the visitor an extra dimension of information.

The integration of all kinds of sustainable and innovative technologies is an attraction in itself. That is the power of the concept: sustainability contributes to the experience of the Dutch Windwheel. It tells the story of the Netherlands and generates a new story for the Netherlands; it is a sustainable icon and an icon for sustainability.

Economic engine

The Dutch Windwheel has a great business case. Based on the current number of visitors to the Netherlands and Rotterdam it is expected that around 1.5 million people will visit the Dutch Windwheel per year. This ensures that the development will be profitable within 10 years. The extra visitors to the city (and the Netherlands) provide an additional boost to the economy and employment. The Netherlands will be more attractive for tourists and the city of Rotterdam and its surrounding area benefit from this. The expected growth in the number of tourists will generate an indirect economic added value of tens of millions per year. These figures are based on hospitality research by NBTC Holland Marketing in 2013.

The Dutch Windwheel can be an important economic engine for the Netherlands and Rotterdam in particular. It must be the global symbol for sustainable development and a showcase for the circular economy. The realisation of the Dutch Windwheel will involve various organisations: developers, investors, operators, authorities and marketing organisations. All the players needed to shape this development are present within the country's borders. With the Dutch Windwheel the global symbol for sustainability will be developed in the Netherlands by Dutch organisations.

The development of the Dutch Windwheel also means a huge boost for employment, both during development and in the exploitation period, when Dutch companies showcase their knowledge and innovations through the Dutch Windwheel to the world.

Some food for thought: Is it worthwhile?

The windwheel will use the innovative Electrostatic Wind Energy Converter (EWICON) that was developed from research conducted at Delft University. EWICON was the subject of a 2008 doctoral dissertation that concluded that the system was capable of producing energy, but with very low efficiencies -- 1.7% at best, in the researcher’s experiments -- far less than the efficiency of a large wind turbine. Of course, the advantage of EWICON is that there’s no moving rotor, so it doesn’t cause vibration in the building. In short, they won’t be putting a giant rotating turbine in the center of the building, so let’s not compare the EWICON to a traditional turbine.

One can only wonder how much energy the EWICON could actually produce, and whether it would be more practical to use another source of renewable energy in the same space. So once again we move to the back of an envelope (this one required two envelopes) to do some arithmetic. These are very round numbers based on averages.

The outer diameter of the Windwheel is 174m. Although they didn’t specify the inner diameter, it can be estimated to be around 87m. That’s a cross-sectional area of just under 6000m². Rotterdam’s average wind speed is 6m/s, so the total available power in the wind is 794 kW. At 1.7% efficiency, the EWICON would generate roughly 13.5 kW, or about 324 kWh/day.

Solar Equivalent

6000m² would hold a 1500 kW (DC) photovoltaic array. Taking into account the average sunlight in Rotterdam and the fact that the panels would be tilted at 90^o (vertical) so they don’t shade each other, such a system could produce an average of 2500 kWh per day - almost eight times the amount that the EWICON is capable of delivering. To make the EWICON competitive with solar PV, it would need to have an efficiency of at least 13%.

On the other hand, a wall of PV panels would block the view through the center of the Windwheel. Suppose we use one fourth the number of panels, tilt them at 45^o and space them out so they don’t shade each other or impede much of the view. That system would produce about 1100 kWh/day - more than triple the EWICON's production. (If you're wondering why cutting the number of panels by a factor of four doesn't cut production by the same factor, it's because the panels will generate more power when tilted at 45^o than they would at 90^o.)

As a tourist attraction, the developers expect the building to become profitable in ten years or less. At this point the Windwheel is a concept. The planners are searching for more partners, and have not yet made the costs public. That makes it difficult to determine the return on investment or the payback period of the EWICON. One thing that raises eyebrows: Delft University, where the EWICON was developed, now says this on its web site:

“In March 2013 TU Delft and its partners unveiled the EWICON. Scientific data has shown that the principle works on a small scale. However there is no evidence that this principle is suitable for use on a commercial scale. At present TU Delft is not actively involved in the further development of the EWICON.”

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