Repetitive swishing sound
Take the massive blades for example. These alone span 65 meters and make a low-frequency sound each time they rotate downward and pass the mast, Pronk says. “It’s a kind of repetitive ‘swishing’ sound,’ so low that you can hardly hear it, but the vibrations make you feel seasick. According to Jan de Laat, an audiologist from Leiden, this can lead to health problems, stress and sleep deprivation.”
According to the plan, the turbines will be placed four hundred meters from the residential area, which is extremely close to people’s homes, Pronk says. A kilometer and a half should be the minimum distance, he believes. De Laat adds another percentage, because the vibrations over the water surface carry far. And that’s not all. The shadow from the blades can cause a flicker effect in some of the living rooms in IJburg.
Pronk: “Did you know that they use stroboscopes to torture people with?” And it’s not just the people in the area who will suffer from the turbines, he says. “The municipality thwarts its own policy with this. Because we have a nature compensation area here as well, with two important migratory flyways.”
Pronk’s campaign is centered around a petition, which has been signed over nine thousand times at this point. The situation in IJburg was quickly picked up by media outlets, such as the Volkskrant, because: look at how all those GroenLinks voters are turning into nimbies (‘not in my backyard’). Pronk expected that accusation, although most GroenLinks voters live in the city’s inner canal belt (or ‘grachtengordel’), according to him. “IJburg is a much more diverse community. I myself definitely don’t vote for GroenLinks.”
Which doesn’t mean that Pronk opposes the energy transition as such. His research at TU/e also focuses on solar energy. In 2015, he designed the Sun-Spotter, a floating ball fitted with mirrors and a solar collector that optimally tracks the sun using an ingenious system. Experiments with the prototype proved that the principle works. “We now need to find a project to determine the economic feasibility.”
Pronk’s protest group Windalarm Amsterdam finds little traction with the municipality in the meantime. “I’ve referred to alderwoman Marieke Doorninck as an ‘ice queen’ before, that’s how little interest she shows. She maintains that the municipality follows the rules. But those rules are based on norms dating back to 1979, when wind turbines didn’t exist yet. GroenLinks wants to present itself as the energy transition party, and it considers wind turbines for IJburg as an indispensable statement in that pursuit.”
Pronk doesn’t think much of Amsterdam’s energy policy. The city wants to generate eighty percent of energy for households in a sustainable manner by itself. “That’s impossible in such a densely populated area. And at the same time, we see how energy-guzzling data centers are being built for companies like YouTube and Google, which get energy for a cent per kilowatt hour.” Why doesn’t Amsterdam aim to insulate its inner city,” he wonders, as he turns the tables on those living in the inner canal belt. “And put solar panels on every roof.”
In general, he doesn’t understand why the Dutch government places wind turbine farms across the country. “Put those things together in a sparsely populated area, or even better, install them offshore.” He’s also not afraid of nuclear energy. “Look at Finland, a country that gets seventy percent of its energy from nuclear reactors. Nuclear plants are very safe these days, and waste storage is well managed. And it’s clean: no carbon dioxide emissions whatsoever, there’s no need for biomass plants, and it would be a great place to store the large number or nuclear missiles we still have stored in our country,” he says with a smile.
Pronk has been featuring in the news regularly since 2014 with research projects abroad, aimed at creating large structures with cellulose-reinforced ice water. He and his team first worked in Finland, but in 2017 he shifted his focus to the Chinese city of Harbin, where he collaborates with the local technical university. At the end of 2019, he erected an Eiffel Tower using 3D-printed ice.