Boasting new technologies and investment, is wind power set to become the dominant renewable sector?Recent analysis suggests that utilising offshore wind farms at depths suitable for fixed foundations could generate 36,000 terawatt hours of electricity a year — much more than the 23,000 terawatt hours a year we need to satisfy global energy demands.
No wind, no fee
Yet wind energy has a similar drawback to other weather-dependent energy sources — no wind, no electricity.
Generating hydrogen fuel from seawater provides an attractive solution to this problem. Offshore wind turbines can operate dually as electricity generators and hydrogen fuel producers. Hydrogen fuel generated while the wind is blowing effectively stores the kinetic energy of the wind as chemical energy, so it can be pumped back to shore for use when needed.
Coupled with falling prices for wind turbines, which have dropped by more than 30% over the past three decades, wind power may finally be able to compete with the convenience and cost of fossil fuels. This is something that all renewable energy sources struggle with due to reliance on existing infrastructure. With a new 53bn barrel oil field having been unearthed in Iran, it’s less likely that the risk of running out of oil will be a sufficient motivator to adopt renewables, even though this is needed to curb global warming.
However, there are plenty of outstanding ideas transforming the capabilities of wind power and making a strong case for its more widespread use.
Gone with the wind — the latest wind power innovations
Where water is too deep for fixed foundation wind turbines to be built, floating wind turbines are becoming a real option. Europe’s second floating wind farm is currently being constructed off the coast of Portugal to take advantage of the stronger winds experienced offshore. Excitingly, the practice is now said to be “at the cusp of large-scale commercialisation”.
Wind turbines can also now be built much taller. Due to the earth’s wind shear effects, wind speeds increase at greater heights, allowing increased power generation. Some recent designs even reach the height of the Eiffel Tower. The rotor blades are designed according to the same principles as an airplane wing, though they have a twisted profile. The efficiency of wind turbines is improved by automatic adaptation of the blades to changing wind speeds. This is done, for example, by rotating the rotor blades into a low wind to increase the amount of energy extracted, or by decreasing the rotor profile in the wind direction to avoid damage by strong winds. This is known as pitch control and the rotor blades can even be designed to generate turbulence that disrupts lift when wind speeds are too high.
Some other key developments include the use of solid silver slip rings, rather than wearable plating, and silver in brushes. Both of these components contribute to electrical communication between the stationary and rotating elements. Silver provides enhanced durability in the harsh conditions of offshore farms. Ultra-capacitors offer longer lifetimes than lead-acid batteries in emergency pitch controls and better performance can also be achieved by the use of tapered, rather than spherical, bearings.
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It’s no surprise that innovations in wind power are coming thick and fast — in 2018, global investment in wind was USD 135 billion. In terms of renewables, this was second only to the USD 140 billion investment in solar energy. Combined, global investment in renewables in 2018 reached USD 290 billion, which exceeded the investment in fossil fuels.