Today began with a brief lecture from Arne Von Garrel, a mechanical and aerospace engineer who is a professor at the University of Twente. During his lecture we learned about the aerodynamics behind the operation and design of wind turbines. The majority of wind turbines used in the Netherlands are lift-based and horizontal axis. This means that the design and orientation of the blades must be optimized to produce the most in each type of wind condition.
A very interesting part of his lecture was learning about the aeroacoustics of wind turbines and how different designs are still being researched and tested in order to reduce the amount of noise produced by wind turbines. A design that is being tested and implemented to achieve this is putting a serrated edge on the turbine blades and it helps to break up the vortices created by them. An interesting fact about wind turbines is that only the blade moving downwards produces noise due to the orientation of the blade.
Following the conclusion of the lecture we travelled an hour and a half to visit a wind farm in the west of the Netherlands. Here we were able to get a tour of the technology and infrastructure that is necessary to operate and integrate wind turbines in the national grid. The wind farm we visited has over one hundred turbines, each of which is over 160 m tall, and they are all connected by an underground system of lines. These lines converge at a battery and grid connection center where the power is either stored or directly put into the national grid.
An interesting aspect of the systems operation is the fact that the energy is publicly traded, this means that the price of the energy changes throughout the day depending on the demand, and the company Pure Energie, which operates the wind farm, must adjust their energy output according to the demand. This is why they have a system of batteries so that they can store energy, and they also have a complex algorithm that monitors the price of energy and adjusts the angle of the turbines and their blades so that they produce more or less energy. The system may even shut down turbines if the price of energy is really low.
The second half of the day was spent in the medieval town of Elburg. During our time in the town, we went on a tour and learned about its history. The town was first constructed in 1392, and the town’s large cathedral was finished in 1396. The town was originally constructed with a moat and was fully enclosed by a large wall. At its peak 2,500 people and 2,000 cattle were housed within the walls.
The town is famous for its very narrow houses that were built right up against the old wall. Once the wall was no longer necessary people would build their house up against it as it required building one less wall. These houses could be extremely narrow/thin in places. The town also features a port, as when it was first constructed it was a coastal town. But, during the 1960s, larger amounts of land were reclaimed, so now boats have to travel through a system of canals before they can reach the North Sea.
