Wind Turbines – How Do They Work?
With just under 7,000 turbines currently generating power throughout the UK – these green giants contributed over 10% of the entire electrical power to the country in 2015.
They’re constantly getting more efficient and it looks like we’ll be seeing even more of them on the horizon soon – but how do they work?
The theory behind wind turbines is intuitive – as simple as a child’s pinwheel – however some basic scientific principles still need to be applied, in order to understand how much energy can be reaped from any one turbine.
The size of the individual turbine is obviously one of the main contributing factors with the physical height of the turbine being paramount. In addition to this, the length of each rotor blade is crucial to maximising the energy produced. Some of the larger turbines have blades that stretch out over 70 metres (over thirty times the wingspan of the average eagle).
Turbines effectively work the opposite way to an electric fan. Instead of transferring electric power into kinetic power, the turbine traps the kinetic energy of the wind and turns it into electric current that can be used to power homes.
Wind blows into the rotor blades, which are designed to direct the wind into each other, siphoning the kinetic energy of the wind. As the wind powers the blades, the gradient of these blades, as well as the lateral position of the turbine itself, shifts to accommodate for the variable wind direction.
The blades spin, this rotates the main drive shaft within the structure of the turbine. This rotates slowly, but quick enough to activate the gearbox which transfers low speeds into a speed high enough to push power to the generator.
Whilst this is happening, recording devices set within and outside of the turbine, work to record and measure the amount of wind being supplied and overall efficiency of the turbine – allowing the managing company to keep tabs on it and see if there’s any need for maintenance. These measurements are used in conjunction with the turbine’s various mechanisms to ensure the best angle for electricity generation.
The generator then runs the power through a DC/DC converter, which steps up the voltage to be used on the national grid.
Once the power joins the grid, the electricity runs through various power stations, on it’s way to the homes of thousands of people around the UK.
Despite the huge bonuses of using windfarms to produce clean, renewable energy – the systems do have their drawbacks. Although months are spent by energy companies (in the run up to a new installation) strategically positioning wind farms, to ensure that the investment made will produced a decent amount of energy; the average UK wind turbine will remain idle for around 14% of each day.
Even when they are active, they often don’t generate maximum power. To ensure the ultimate efficiency of an entire wind farm, it is imperative that these turbines are spaced at a good distance apart from each other – otherwise the disruption of wind will affect the amount of kinetic energy that other turbines receive. This means that a windfarm, consisting of just a handful of turbines, could stretch out for several square kilometres.
They might not be perfect, but wind turbines are constantly being developed and perfected to provide a cleaner, greener future for all of us.