Could floating turbines be the answer to wind energy?

Wind farms are one of the best sources of renewable energy for the UK, but while they are cheap, they are also an eyesore for anyone nearby which is why many don’t want them in the countryside. Putting wind turbines out at sea is one alternative, but building fixed structures in water is not easy, and so the idea of the floating wind turbine is being explored. What challenges do traditional wind turbines face, how do floating turbines solve this, and are they feasible?

What challenges do traditional wind turbines face?

While many around the world push for solar panels as a source of renewable energy, the UK sees far larger gains with wind energy, undoubtedly thanks to our windy climate and little sunshine. In fact, wind energy is so plentiful in the UK that there have been numerous times in the last few years when wind energy was the biggest source. 

Now it has been explained at Electropages many times that wind energy, like most renewable energy sources, has issues with availability. The sun doesn’t always shine, and the wind doesn’t always blow which sees energy grids still reliant on fossil fuels for reliable energy. The solution to this comes in the form of energy storage, but exactly which technology will prevail is still up for debate.

But while engineers struggle to find the ideal energy storage solution, social challenges have also prevented the widespread adoption of wind energy. Despite the low price of wind turbines, their massive size makes them an eye sore for miles, and as such most do not want to live near them. Furthermore, the high speed of the blades often kills birds and bats which has many worried about the effects of wind turbines on wildlife. 

Thus, many look towards offshore wind farms that put wind turbines as far away from populations as possible. In fact, the lack of obstacles and land features make the sea ideal for capturing wind energy, and the large open spaces also allow for wind turbines to be significantly larger out at sea. 

But just like how there is no such thing as a free lunch, wind turbines out at sea also face numerous challenges with installation cost being a major one. To keep costs low, turbines can be installed at shallower waters, but this impacts their ability while also limiting where they can be installed.

Introducing the floating wind turbine

One idea that numerous companies are quickly trying to capitalise on is floating wind turbines. While traditional offshore wind turbines are mounted into the ground, a floating turbine instead floats on the water and uses multiple anchors to prevent it from drifting. The advantage of using a floating platform and anchors is that a floating turbine can be installed farther out at sea and support deeper waters. Not only is the wind stronger in these locations, but the lack of a fixed mounting significantly decreases the cost and installation time.

Some floating turbine designs use a singular central tank that uses three anchor points. By allowing water into the tank, the submerged depth can be controlled, and this is important during storm conditions which could cause structural damage. The use of a floating design also allows the entirety of a wind turbine to evenly distribute strong forces from damaging winds and large waves which increases the lifespan of the turbine (i.e., it is better to rise with the waves and sway in the wind than to resist). 

Another design for a floating turbine uses a structure of multiple columns similar to an oil rig where each column has its own pumps and controls for providing stability. One such example was recently reported by the BBC that is currently in operation ten miles off the coast of Scotland. The demonstrated platform was used to house a 190-meter-tall turbine that generated enough power for 35,000 homes.

According to RenewableUK, it is believed that floating turbines will not only make up 50GW of energy production by 2050, but will also add in excess of £43 billion to the UK economy and employ over 29,000 for design, management, sales, and repairs. 

Are floating turbines practical?

By far, floating turbines make the most sense when it comes to offshore wind farms for numerous reasons. The first is that the floating design eliminates the need for expensive foundations which gives floating turbines more economic incentive. Combined with stronger winds at sea and the ability to keep the turbines out of sight, floating turbines will also be popular amongst environmentalists and stubborn residents alike. 

However, turbines that can float freely on water also present some serious safety challenges. Should any of the anchors fail, it could allow the turbine to drift and collide with boats, other turbines, or infrastructure. But considering that such a turbine would drift slowly, it would be likely that a ship could quickly assess damage and tow the turbine back into position.

Overall, it seems that floating turbines present the best option for modern offshore wind farms. Now that numerous companies are working to develop their own unique solutions, it won’t be long before floating turbines become the favourite for offshore wind farms.