A typhoon-proof wind turbine is generating an energy shift for remote islands

Vulnerabilities in Japan’s power infrastructure were laid bare in natural disasters such as the Great East Japan Earthquake and Tsunami and devastating large-scale typhoons. Largely due to the massive destruction caused by the 2018 Japan floods, Japan surpassed the Philippines in facing the greatest damages from extreme weather events as calculated in the 2020 edition (PDF, p. 6) of the Global Climate Risk Index.

Since the nuclear disaster at Fukushima, Atsushi Shimizu has worked toward an energy shift, creating a unique wind turbine with vertical cylinders that act as wind blades. It generates power by applying the physical principle known as the Magnus effect. After his invention was patented, Shimizu founded his company, Challenergy. He has since overcome the efficiency problems of the original design, and now his bladeless wind turbine can generate power even in the strong gales of a typhoon. He began testing his designs in the field with a 1-kilowatt test machine installed in Nanjo City in Okinawa in 2016.

Since then, trends in wind power have taken a dramatic turn. Shimizu says there was a boom in small wind-turbine system development, both domestically and from abroad, triggered by Japan’s adoption of the feed-in-tariff (FIT) system. “Just like solar-energy systems, our focus at that time was to leverage the FIT framework,” he says. “So we were working on a larger, 10-kilowatt system to make it more efficient and profitable.” However, Challenergy soon found it difficult to penetrate a market dominated by lower-price blade turbines made outside Japan. And with energy prices dropping below half their original values, it became apparent that it would be difficult to turn a profit within the FIT framework.

Once Shimizu could prove the effectiveness of his technologies with the 1-kilowatt test platform, which succeeded in generating power in typhoon conditions, he refocused to pursue his original vision of a worldwide shift in energy. He wanted to build a business model that did not rely on FIT while continuing development on the 10-kilowatt turbine. In 2018, Challenergy installed a mass-production prototype at a test site on Ishigaki Island, Okinawa, with a product debut planned for 2020.

Due to their design, wind turbines become more cost-efficient as they increase in size. Standard wind-turbine manufacturers are vying for larger and larger sizes, and supersize models with blades reaching 100 meters in length are in the works. “Throughout the history of wind-power business development, one constant has been competition for larger and larger turbines,” Shimizu says. “The focus now is only on those companies that can manage to make the largest turbines. They’re like parades of giant dinosaurs out there.”

In contrast, Challenergy’s strategy is to avoid competing in the cutthroat giant-wind-turbine market and instead pursue the niche market of power generation for remote islands.

“Island communities often rely on diesel generators for their electricity, but nowadays securing fuel and generating affordable power have become major issues,” Shimizu says. “High hopes have been placed on renewable energy sources, but there is no easy solution at hand. While islands lack the land needed for solar-power farms, wind is in ample supply. But constantly changing wind directions and wind speeds result in frequent damage to blade-based turbines. With our turbines, island communities can gain access to a renewable energy source that could one day replace diesel generators.”

One of the largest hurdles to success for a venture business is creating a product design suitable for mass production. This is true for Challenergy.

“For our small-scale 1-kilowatt turbine, not much stress was applied to the structure, so it was relatively easy to come up with a design that offered both performance and structural strength,” Shimizu says. “However, as the turbine gets larger, you need to optimize its weight and strength to maintain mass-production viability. Also, when making a physical product, design is paramount; you can’t just fix it after the fact like you can with software. You have to be sure of your work before you commit to production.”

Challenergy had used Autodesk Inventor from its founding; as its projects grew in scale, it was soon using the full capabilities of Inventor Nastran for running simulations. “The advantage of using simulations is that we can measure stresses in fine detail, whether at different angles of wind direction or within the arm structure itself, where real-life measurements cannot be performed,” Shimizu says. “Once we’ve accumulated enough simulation data, we can quickly adjust our design parameters. Being able to quickly move through the design and analysis phases of the [Plan-Do-Check-Act] PDCA Cycle is a matter of survival for venture companies like us.”

The first location for a 10-kilowatt turbine in Challenergy’s island-based deployment strategy is in the Batanes province of the Philippines. “It is geographically close to Ishigaki Island and experiences typhoons often, so conditions are similar,” Shimizu says. “While tourism is the main industry there, its power-transmission network is vulnerable, and blackouts occur on a daily basis. A local restaurant we visited there had its own small generator, and each time the power went out the staff would switch it on.”

The Philippines has more than 7,000 islands—hundreds of which are inhabited and require electricity. “Supplying islands with power is not only a problem in Japan or the Philippines; it’s a worldwide energy challenge,” Shimizu says. “We are receiving more inquiries from island communities around the world—many of them famous tourist destinations. It vindicates our strategy seeing that demand is so high.”

Island nations have large electricity demands for supporting their essential tourism industries. However, the pollution caused by diesel generators is at odds with the environmental concerns of the tourism sector.

“Solar power is not an option, because any suitable land for solar farms has already been settled,” Shimizu says. “It may sound strange, but the hours of direct sunlight on islands are often limited. This makes it hard to bank on solar power for island communities. While wind is almost always blowing over islands, the island itself disturbs the wind flow, creating problems for conventional blade-based turbines and the risk of machine damage. Our wind turbines fit the niche needs of island communities better than any other renewable energy source, which gives us a clear direction for our strategy going forward.”

Challenergy’s first wind turbine in the Philippines became fully operational in Batanes in August 2021, and Shimizu says he will not stop at providing islands with self-sufficient power.

“We can tap into the limitless potential of the ocean and combine it with wind power to realize a hydrogen-based society for island residents,” Shimizu says. “It all starts with providing power to these small islands and moving forward from there. If we can get one island to realize a 100% hydrogen-based society, such a paradise on earth free of fossil fuels will surely draw tourists. Ultimately, starting with Japan, we want to transform island nations around the globe into sources of hydrogen energy. If we can harness the power of typhoons as a resource for producing hydrogen, and then export it, that will drive the formation of a worldwide hydrogen-based society. It would be a dramatic paradigm shift for island nations, which currently rely on importing their energy.”