'The Blade' the Dutch windmill

Sometimes, you stumble upon news that makes you raise an eyebrow—whether it's a strange new invention, an unexpected consequence of climate change, or a surprising display of human clumsiness. It leaves you thinking, "Well, that's remarkable."

Experts and scientists initially believed that it was impossible to create a small, home-based wind turbine that could generate significant amounts of electricity. However, the new Dutch windmill, called The Blade, has defied those expectations. Despite operating in less-than-ideal conditions and requiring only minimal wind power, this turbine is able to produce between 2,500 and 3,000 kilowatt hours of green electricity annually. To put that into perspective, it generates enough energy to meet the average electricity needs of a typical Dutch household for an entire year.

After years of hard work and overcoming many challenges, Cell Technologies reached a significant milestone on Saturday, 28 September. They have secured patents for The Blade wind turbine and submitted an application for the mandatory NEN standard, which is required in the Netherlands. In front of shareholders and stakeholders who strongly support the project, The Blade was officially presented at the company’s facility in Etten-Leur. Production is set to start by the end of 2025, with plans to manufacture around 60,000 wind turbines each year, potentially more. According to directors Fran?ois Huijbregts and Marcel Naaktgeboren, their mission is to combat energy poverty by enabling people to make their homes more sustainable and generate their own green energy.

Placement without a permit (almost everywhere)

The first model, called The BladeX1, is 1.40 meters tall and 60 centimeters in diameter, making it a size that is allowed in most Dutch municipalities. It is installed on a pole against the side of a house, not on the rooftop. Only the turbine, which is 90 centimeters tall, extends above the roof. As long as this extension is less than 10 percent of the house's height, it typically complies with local zoning regulations. The BladeX1 operates quietly, without vibrations, and unlike larger wind turbines on land and sea, it poses no threat to birds. According to Huijbregts, birds perceive it like a chimney and simply fly around it.

The Blade all over the world

Once production begins, every Dutch citizen will have the opportunity to install The Blade windmill on their roof, balcony, or in their garden, offering a convenient way to generate green energy. However, the creators of The Blade envision broader applications beyond individual homes. The windmill could be placed on flat rooftops, in farm fields, or other locations without electricity access. Additionally, it can be mounted on lampposts, where it is hardly noticeable but generates renewable energy for public spaces.

The Blade also holds potential for addressing energy needs in countries like India or Kenya, where wood is still commonly used for cooking. By providing a clean, electrical alternative, significant reductions in CO2 emissions could be achieved. Initially, the focus was on the Dutch market, but interest has now grown globally, with inquiries coming from countries as diverse as India, Japan, South Africa, Turkey, France, and Kenya. The global appeal highlights The Blade's potential to contribute to the energy transition worldwide.

Scientific disbelief

In the Netherlands, the creators of The Blade faced skepticism and disbelief. Many scientists doubted that such a small windmill could generate a significant amount of electricity, and as a result, refused to collaborate. On top of this, the process of testing prototypes, applying for patents, and undergoing the necessary NEN certification took several years. The creators, Huijbregts and Naaktgeboren, describe the journey as long and complicated, filled with unexpected challenges. They also faced considerable resistance from the scientific community. Despite these obstacles, their firm belief in the project kept them moving forward. If they hadn’t been fully convinced of its potential, they admit they would have given up long ago.

Betz's law

The resistance to small wind turbines, like The Blade, comes from experts who argue that wind turbines on a balcony or roof can't generate enough energy to be efficient. This belief is based on Betz's Law, named after Albert Betz, who discovered in 1919 that only a maximum of 59.3% of the wind's kinetic energy can be converted into mechanical energy by a wind turbine, which then turns into electricity.

In practice, this law favors tall wind turbines with large rotors, which can capture more wind and produce more power. Smaller wind turbines, like those placed on roofs, typically generate much less energy. This led organizations like the Consumers' Association to conclude that small wind turbines are not financially worthwhile. However, The Blade challenges this assumption by demonstrating that even small wind turbines can generate enough energy to be a valuable investment.

Wind energy used twice

The inventors of The Blade kept its working mechanism secret for a long time to prevent it from being copied before securing patents. Now that the patents are in place, they can explain how it works. The Blade 'circumvents' Betz's Law, which limits the amount of wind energy that can be converted into mechanical energy, in a few clever ways.

First, a plastic hood with openings, which rotates with the wind like a weather vane, ensures that the aluminum blades only catch the wind without being slowed by wind vortices. This allows the blades to maximize their efficiency. Second, the hood's vane ensures that the wind at the back is not lost but is instead guided through the mill again, allowing The Blade to capture more energy.

While Betz's Law still technically applies, The Blade uses the wind's energy twice, effectively increasing its efficiency.

Transmission

A common issue with small windmills is that they either don't produce enough power or can't spin fast enough to drive the generator or dynamo to generate significant electricity. The inventors of The Blade solved this problem by using a transmission system, similar to the gears in a car.

In The Blade, the rotating blades turn a large gear. This large gear is connected to progressively smaller gears, eventually reaching the generator. This setup allows the windmill to produce enough power with less torque, meaning it doesn't need as much wind force to generate significant electricity. The smaller gears speed up the rotation, enabling the windmill to generate power efficiently even at lower wind speeds.

According to the inventors, no other windmill uses this system. The Blade can reach full power at wind force 4, and if the wind gets too strong, built-in software slows down the windmill to prevent damage.

Conservative and preliminary estimate

The inventors of The Blade are hesitant to reveal exactly how much power it can generate until official testing (the NEN test) is completed. This test, conducted in a wind tunnel, will determine the precise amount of electricity produced under specific wind conditions. So far, the company has tested The Blade twice, not in optimal open-field or high-altitude environments, but in conditions similar to those found in residential areas. The tests used wind data from five meters high, though The Blade is usually installed at ten meters.

Despite testing under less-than-ideal conditions, Huijbregts cautiously estimates that The Blade can generate between 2,500 to 3,000 kilowatt hours of electricity annually. The company is also developing a larger version, called the L1, which will be 2.5 meters high and 1 meter in diameter. While the L1 may be too large for Dutch homes, it is expected to be well-received abroad, where space is less of a concern. The L1 could potentially generate 10,000 kilowatt hours of electricity per year.

Production starts in 2025

The Blade will soon be assembled in a production hall in Etten-Leur, which will create around eighty jobs. However, production can only begin once the product receives NEN certification, which is necessary for any product to be sold in the European market. The company expects to receive NEN approval by April next year at the latest, but they are hoping for it as early as January.

Once approved, it will take about another six months to start assembly because the molds for the windmill still need to be manufactured, which is a costly process. Cell Technologies aims to begin producing 60,000 units of The Blade annually by fall 2025, though they are prepared to increase production if needed. The company is already in discussions with multiple interested buyers, indicating strong demand for the windmill.

Energy for all people

To make The Blade financially accessible to as many people as possible, it is priced at €2,500, excluding VAT, the pole, and installation costs. This relatively low price aligns with the inventors' mission to promote affordable green energy. Huijbregts and Naaktgeboren, who both come from IT backgrounds, met in 2015 and realized they had complementary skills.

Huijbregts was motivated by a desire to make his own home energy self-sufficient, but he discovered that solar panels alone weren't enough. He searched for a small windmill to fill the energy gap but found that such a product didn’t exist. Naaktgeboren, on the other hand, was focused on reducing energy poverty in the Netherlands, particularly for low-income households, many of whom rent their homes and are often overlooked when it comes to sustainability investments. He noted that while municipalities offer energy subsidies, they don’t invest in long-term sustainability for these tenants. Huijbregts likened this to giving people food without teaching them how to fish.

Their company, Cell Technologies, operates under the motto "Energy for all people," reflecting their vision of making sustainable energy solutions accessible to everyone.

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