A Japanese company has built the world’s first typhoon-resistant wind turbine. The prototype is capable of transforming severe gales into electricity and could in theory harness enough energy from one tropical storm to power Japan for 50 years. Susanne Steffen reports from Tokyo.
Normal wind turbines shut off at wind speeds of around 25 metres per second. Typhoons – which frequently rage across Japan at speeds of 40 metres per second or 144 kilometres per hour – are infamous for destroying propeller systems.
“Most Japanese wind turbines are damaged by typhoons,” said Atsushi Shimizu, which partly explains why the Japanese government is investing far more into solar power than wind power.
“But Japan’s potential in wind power is far greater, it’s simply not being used,” explained the 37-year-old engineer and entrepreneur, whose start-up company Challengergy has developed what he calls the world’s first typhoon turbine
Withstood the first typhoon
If Shimizu’s invention passes real-life tests, this situation could change. Since July, a prototype of the wind turbine has been operating in Okinawa in southern Japan, a region plagued by typhoons.
At the beginning of September, the first typhoon hit the new wind turbine with top speeds of 30 metres per second. The turbine generated electricity without interruption, as Shimizu’s company proudly announced on its website. The engineers have yet to provide specific details about the amount of electricity generated.
At first glance, the seven-metre-high construction looks more like a giant whisk than a wind turbine. Two features in particular distinguish the typhoon electricity generator from conventional wind turbines: firstly, the turbine’s suspension isn’t fixed, allowing it to adapt to the sudden changes in wind direction during a typhoon. Secondly, rotor speeds are controlled by means of what’s known as the Magnus Effect to prevent the rotors from spinning out of control. According to Challenergy, this means that the turbine can withstand speeds of up to 80 metres per second, or 288 kilometres per hour.
Electricity for 50 years
In initial tests, the machine functioned at an efficiency of 30 per cent; quite low when compared to the 40 per cent efficiency of conventional wind turbines. But the immense amounts of energy that can be generated during a tropical storm arguably offset this deficiency.
A strong typhoon would produce so much kinetic energy that it could power Japan for 50 years, said Shimizu in reference to calculations from the Japanese transport ministry.
An average of 11 typhoons approach the East Asian island nation each year, with around three making landfall on Japanese soil. But in this year alone Japan has already been struck by six tropical storms, and scientists warn that more frequent and stronger storms should be expected in the future as a result of climate change.
Storage still unclear
Shimizu’s company has received financial support from the government’s New Energy and Industrial Technology Development Organisation (NEDO). But before these typhoon turbines can revolutionise the wind power industry, a few problems still need to be solved. Among these: even if Shimizu is actually able to produce electricity from typhoons, it’s still unclear how this massive amount of electricity can be stored.
For Japan, a country that currently imports more than 80 per cent of its energy, a breakthrough in typhoon technology could represent a step towards energy independence. Until the Fukushima nuclear disaster in March 2011, the country relied almost exclusively on nuclear power. But ever since the triple nuclear meltdown, public opposition to nuclear energy has grown.
In the future, the government plans to make nuclear energy and renewable energy equal pillars of the country’s energy supply.