Wind is ambiguous. It can be devastating. It can be exciting. If just 2% of wind was captured, it would solve the planet’s energy needs in a heartbeat.
In the UK, the wind energy industry is celebrating. Last month, the cost of renewable energy dropped dramatically to undercut by almost half the government’s projections for 2025. At £57.50 per megawatt-hour (MWh), it is far cheaper than the state-backed price of £92.50 awarded in 2016 to Hinkley nuclear power station.
Since the government ruled out new onshore wind farms in England energy companies have been forced offshore. The wind turbines have grown steadily larger, as have the farms to which they belong.
Dong’s Hornsea Project Two will span 480 sq km
A large jagged blue diamond for Project Three
An even larger blue rocket shape for Four.
The reason for the falling cost of wind energy?
Over time, the diameter of the blades have enlarged. A turbine commissioned in
2002 swept 80 metres
2005 - 90 metres
2011 - 120 metres
2020 - 180 metres
Wind energy costs less, and will go on costing less, because the turbines are growing taller and the blades longer.
Two scientists from the Carnegie Institution for Science at Stanford University, California, published a study that suggested a wind farm the size of India, in the North Atlantic, could power the world.
And yet despite the size of its enormous machines, the offshore wind industry is still in its infancy. Wind turbines may look alike, but they're not. There are fixed turbines and floating turbines, which can access deeper seas, turbines with gears and turbines without. The sight of three blades harmoniously turning has become commonplace.
Ken Caldeira is one of the two Stanford climate scientists behind the idea of a North Atlantic wind farm the size of India. He says it is important to know that when wind turbines are arrayed in rows, the extraction of wind by the first row reduces the amount of wind available for the second row, and so on. Row by row, the wind’s potential diminishes.
To counter this effect, turbines need to extract energy from the wind that’s above them. What Caldeira found was that that is exactly what can happen in parts of the North Atlantic, where heat “pours out of the ocean”, causing greater “cyclonic activity”.
The hurdles facing the wind energy industry remain immense. Technical challenges include the difficulty of storing the energy captured. Batteries for this purpose are still developing and are crucial to securing the supply.
Caldeira reckons the total amount of power in winds globally is 50 times bigger than the total amount of power used by human civilisation, and that if we were to power civilisation by winds, we would need to capture about 2% of winds today.
Wind turbines on kites are in research and development. According to Caldeira, the jet stream is the largest, most intense renewable energy source on the planet, 20 times as potent in every square metre as direct sunlight in the middle of the day.
No one thinks that wind alone offers the answer to the world’s energy needs. But for now, at least, the possibilities are boundless.