Climate change and wind power: The winds of change

There is currently around 1 terawatt of installed wind power globally, equivalent to the annual electricity consumption of the Netherlands. This capacity is expected to double by 2030, even though this will be below net zero targets. Wind is already an important part of the electricity mix in many states. The UK, for example, recorded a 29% electricity share from wind power in 2023; it was 18% for the EU over the same period.

However, climate change will impact wind power. There could be changing wind patterns, reducing wind in many regions; increased storm intensity; growing likelihood of lightning strikes; and heatwaves lowering the lifetime of equipment and increased downtime of the turbines.

Taking wind out of sails: Wind droughts

In the second half of 2021, Northwestern Europe suffered a 'wind drought', with wind speeds falling 15% below average. This fall is largely associated with Arctic warming, narrowing temperature differentials between the tropics and the pole, and so reducing Northern hemisphere wind speeds. It was not a one-off. In winter 2022, wind speeds again plummeted to 'barely a breeze' over several days. Lower than average wind speeds over northern parts of Europe have been associated with development of high-pressure patterns, also referred to as 'blocking', over the northeastern Atlantic and Greenland.

Wind drought has significant consequences. In September 2021, wind contribution to the UK electricity mix fell to just 2%, necessitating the reignition of two mothballed coal plants. In December 2022, the wholesale cost of UK spot electricity rose to a record high, driven by a fall in wind power and a rise in natural gas prices.

Wind drought can be particularly serious as the relationship between wind and electricity production is not linear. A 10% wind speed decline can result in more than 30% reduced output. Wind turbines can only operate above a minimal wind threshold; and productivity is dependent on wind magnitudes, direction, pattern and duration.

The Intergovernmental Panel on Climate Change (IPCC) states that climate change will affect aggregate global windspeeds with projected average annual wind speeds dropping by 10% by 2100, albeit with large regional variabilities. One study suggests 11% of global wind power plants will experience a 5% decrease in average wind speeds in a low emissions scenario (SSP1-2.6, associated with warming below 2°C). This could increase to 18% in a high emissions scenario (SSP5-8.5 associated with warming of above 4°C). Risk transfer solutions like index based wind resource volatility cover can help the investors and stakeholders by providing protection against financial risk due to uncertain wind speeds. 

Stormy weather: Wind turbines and storms

Most wind turbines are engineered for facing winds of 112 mph, equivalent of a category 3 hurricane. Speeds above this can damage rotors and even bring down turbines. Extreme wind speeds also affect productivity as turbines shut down beyond a certain threshold to avoid damages. 

Tropical cyclones and severe storms impact power generation in two ways: by shutting the turbines at high speeds and possible infrastructure damage. By and large, wind farms have proved robust in coping with storms. Hurricane Harvey passed over several wind farms in Texas in 2017, leaving them largely unscathed. However, strong enough winds cause damage. Typhoons Jebi and Cimarron toppled over several turbines in Japan in 2018. Windstorms caused rotors to become detached in Scotland in 2023; while a tornado brought down five turbines in Iowa in 2024.

Observations indicate a global decrease or no change in the frequency of tropical cyclones, however, the proportion of major tropical cyclone intensities (Category 3-5) has increased. This evolution is projected to continue in the decades ahead. An increase in the average and peak wind speeds during cyclones is also expected because of climate change. Additionally, tropical cyclones are projected to shift northwest and north, with greater impact on eastern China, Japan and Korea among others. Damages caused by more intense storms will be compounded by rising sea levels, inland flooding from extensive rainfall, and changes in wave patterns.

Hot sparks: Lightning strikes and rising temperatures

An estimated 5.4% of turbine blades are hit by lightning every year with significant regional variation. Despite protection systems, lightning strikes cause 60% of operational blade losses and 20% of operational wind losses. With climate change, lightning frequency is estimated to increase by 12% for every 1°C warming (Figure 3). US could see a 50% increase in lightning strikes by 2100. Increases in turbine tower and rotor size increase likelihood of lightning strikes. In 2030, wind turbines with heights of 230-250 m are expected, roughly 80% of the height of the Eiffel Tower. 

Extreme heat events with a 10% pre-industrial probability have a 30% chance of occurring today. Temperatures of 35-45°C can impact the life of battery cells and other equipment. Turbines may be designed to shut down when temperatures go beyond 45°C to prevent damages, but this can result in lower outputs from the wind farms.

Climate change, wind power and implications for insurers

• Planning expected electricity output must take account of projected changes in wind speeds: In certain locations, aggregate average windspeeds may fall. Business owners need to include a range of wind projections in planning investments. 
• Risk prevention measures must acknowledge growing climate risk. These include turbines with greater wind gust and lightning strike resilience; as well as greater heat resistance. 
• Offshore failures are a lot more expensive than onshore: Offshore turbines can be larger and windspeeds are typically higher. However, post-incident downtimes are longer, and power losses greater. It costs 5-10 times more to replace an off-shore than on-shore turbine.
• Wind investments will inevitably become more risky: Easier sites will be developed first, riskier ones later, and risk will be exacerbated by climate change. Texas, for example, has huge potential for wind power; but has large storm exposure and projected increase in number of days with temperatures over 45℃.