Close up image of a wind turbine's propellers with green fields, blue sky and sunset in the background.

Can Waste Heat Recovery Mitigate the Impact of Global Stilling?

Renewables only account for around 11% of the energy currently used worldwide, but increasing awareness of the climate crisis and the pledge to reach net zero mean that businesses, industries and countries are embracing renewable energy at a faster pace.

However, finding a reliable and cost-effective form of renewable power is critical for widespread adoption. To achieve net zero and create a sustainable future, it’s vital to fulfil the demand for reliable renewable energy, particularly given the relative reliability of energy from fossil fuels. 

As many forms of renewable energy are weather-dependent, there are legitimate concerns over its continued reliability and accessibility. For wind power, in particular, the much-debated issue of global stilling raises questions about the impact that climatic changes could have on renewable energy generation. 

In this article, we’re taking a closer look at the impact of global stilling on wind energy and asking whether weather-dependent renewables can provide the reliability required or whether non-weather-dependent renewables are essential for a successful global transition to carbon-free power. 


How Reliable is Wind Power?

Deriving energy from wind isn’t a new concept. In fact, you can go back centuries and find examples of wind-powered water pumps and windmills being used to facilitate industry. After all, sailboats were reliant on wind to propel them as far back as 5,000 BC.

Amidst the industrial revolution and the rise of fossil fuels, renewable energy, such as wind, took a back seat and it’s only relatively recently that it’s come to the fore once again. Throughout the 20th century, advances in technology enabled wind power to be transformed into electricity, laying the groundwork for ‘wind energy’ as we know it today.

Globally, wind power is now the second most prolific source of renewable energy, producing 1,591 terawatt hours out of a total 7,444 terawatt hours of renewable energy in 2020.

Wind power generation has increased significantly since the 1970s and the industry has grown at a rapid pace over the past two decades. Indeed, reports of record wind power production and positive forecasts led many to believe that wind power will continue to be a frontrunner in the race to net zero.

However, the reliability and security of wind power may not be as clear cut as it seems. There is a potential environmental phenomenon that could threaten the industry and put renewable energy generation at risk: global stilling.


What is Global Stilling?

In its simplest form, global stilling is the decrease in wind speeds close to the Earth’s surface. Despite peaks and troughs in wind speeds worldwide, statistics show that wind speeds have been dropping since the 1960s. In 2021, wind strength across Europe dropped by as much as 15% in places, fuelling concerns about the impact global stilling could have on wind energy.

However, global stilling is not a universally accepted phenomenon, nor is it completely understood. In some locations, wind speeds have actually increased since 2010, giving rise to the belief that global stilling could be in a state of reversal. 


Is Global Stilling a Threat to Wind Power Generation?

To accurately determine whether global stilling is a threat to wind power, we must examine two issues. Firstly, the impact on wind power generation if wind speeds are declining globally and, secondly, the impact if global stilling is in reversal. 

The Impact of Declining Wind Speeds

On one hand, the growth of the wind power industry amidst ongoing global stilling may indicate that it’s unlikely to bring the sector to a halt. Certainly, no-one is expecting wind power to decline at a rapid pace. As technology advances and we become more efficient at storing and transporting renewable energy, it’s true that global stilling could be less of a threat to global wind power than once thought.

However, the fact remains that ‘lower wind speeds = less wind power generated’. While the global highs and lows of wind speeds may even each other out and maintain relatively high production levels worldwide, this will be cold comfort to turbine owners who are relying on local wind speeds to power their businesses or homes.

Furthermore, if global stilling causes a fall in wind speeds in the future, it may result in energy price increases. Renewable energy may need to be transported further to provide energy to those that need it, for example, which will potentially send the price soaring.

With existing rates of global wind power generation under threat, it follows that the need for even higher rates of wind energy could be concerning. To stay on track to reach net zero by 2050, wind power growth must triple over the next decade. 


Such growth requirements are a challenge for any industry but, when you’re reliant on environmental factors, the possible uncertainty could dissuade people and businesses from relying too heavily on wind power – particularly when there are other, arguably more reliable options, available.

The Impact of Global Stilling Reversal

If we assume that global stilling is in reversal and wind speeds are increasing, this may equate to an increase in wind power generation too. In fact, some experts attribute as much as 50% of wind power growth in the U.S. between 2010-2017 to global stilling reversal.

So, is the regional increase in wind speeds seen over the past decade enough to conclude that global stilling is not a threat to wind power generation? Not quite. 

The increase in wind speeds has occurred in some locations, while declining wind speeds have been observed in others, such as Europe. Furthermore, the relatively short period of alleged reversal amidst a decades-long decline may mean that it’s too early to conclude that the threat of global stilling is no longer relevant.

With the causes of global stilling still being investigated, we don’t yet know whether the regional rise in wind speeds is a forecast for the future or an anomalous blip amidst a slow decline. 

In addition to this, the increase in wind speeds over the U.S. may have contributed to an increase in wind power generation, yet this increase only equates to a 2.5% boost to the country’s wind power capacity. At a time when the wind energy industry needs to treble its growth within a decade, even the reversal of global stilling may not be sufficient to put wind power on track to achieve global net zero ambitions. 


What Do Varying Wind Speeds Mean for Wind Power?

At first glance, it might seem logical to conclude that declining wind speeds are a threat to wind power and global stilling reversal is beneficial to wind energy, and in some ways this is true. Yet the impact on wind power generation is not quite so clear cut. 

Whether or not wind speeds are rising or falling, it’s their variability that poses an inherent threat to wind power. Like many forms of renewable energy, wind power is dependent on climatic conditions and herein lies the problem.

For homeowners, businesses and entire regions to truly embrace green energy, reliability must be guaranteed. After all, an on-site wind turbine might generate enough renewable energy to power a factory but what happens when local wind speeds fall? Will owners need to find and fund energy storing devices and hope that the wind speed increases before their reserves run out? Or will they rely on fossil fuels as a back-up, thereby increasing their CO2 emissions, potentially attracting financial penalties and damaging the environment?

Despite its benefits, the inherent weather dependence of wind power could prevent the sector from achieving the rapid growth required and affect the perception of wind power as an infallible source of renewable energy. If so, additional, non-weather-dependent forms of renewable energy must be used instead or in conjunction with wind power to safeguard the transition and provide increased reliability. 


Is Waste Heat Recovery a More Reliable Source of Renewable Power?

Just like wind power, heat energy has been around for centuries. Many people maintain that the sun’s heat was the first form of energy, which would make heat power the original form of renewable energy!

Of course, converting heat into clean electricity is a relatively new concept but one that’s becoming more widely used. From cruise ships to geothermal plants and Japanese onsens to Icelandic villages, you’ll find Climeon Heat Power Systems being used to generate carbon-free electricity in a wide variety of environments.

Although wind power is currently more widely used globally, waste heat recovery does have advantages over this form of renewable power, particularly when it comes to reliability.

With a Heat Power System, clean electricity can be produced reliably and predictably. As long as waste heat continues to be emitted from the specified source, heat power modules will continue to produce clean energy around the clock. 

Let’s return to the example of a factory owner. The industrial processes taking place within the factory produce waste heat. Instead of letting this by-product disappear into the ether, the factory owner uses it to generate clean electricity. This clean energy helps power the factory and the continued industrial processes generate more waste heat, thus producing more renewable energy….and so the cycle continues ad infinitum.

By using waste heat recovery systems in this way, clean electricity can be generated 24/7/365, with no dependence on weather or climatic conditions.


Heat Power vs Wind Power

Producing wind power on-site requires considerable resources, particularly if landowners want to produce clean energy in vast amounts. Business and property owners will need to find sufficient space to install turbines and ensure that wind is not blocked by the surrounding topography or infrastructure, for example.

While some people and organisations may assume that purchasing electricity generated by wind power via traditional energy firms is a sustainable alternative to on-site generation, this presents two problems. Firstly, off-grid premises, such as oil wells, will not have access to this power source and, secondly, it puts energy users at the mercy of external energy companies when it comes to availability, reliability and pricing.

In contrast, Climeon’s Heat Power Systems are compact, modular and scalable, which enables them to be installed in a range of locations. From power plants to the confined engine rooms on container ships, on-site clean energy can be generated with minimal space requirements.

As a non-weather-dependent form of green energy, there’s no doubt that the reliability of heat power overcomes many of the challenges facing climate-dependent renewables and provides industries and regions with a guaranteed source of clean electricity.


Diversifying the Energy Mix with Heat Power

Transitioning to a net-zero future needn’t mean choosing between heat power vs wind power or any other type of renewable energy. Instead, waste heat recovery can be used to diversify the energy mix and safeguard access to carbon-neutral power. 

Our modular and scalable approach allows heat power to be integrated alongside existing renewable energy solutions. If a factory owner wants to safeguard other renewable energy resources, Climeon heat power modules can be installed on-site and used in addition to wind turbines, solar panels or other renewables, for example.

As such, waste heat recovery can mitigate the impact of global stilling and support global stilling reversal by ensuring that users of wind power have access to a more reliable form of carbon-free energy to safeguard their sustainable operations. 

This ability to transition towards reliable renewable energy at a staggered pace highlights why waste heat recovery is such an attractive option to industries in need of dependable carbon-free energy and why Climeon is a leading provider of waste heat recovery solutions.


What Does the Future Hold?

Although global stilling and its potential reversal remains a matter of debate, the precarious and intermittent nature of weather-dependent renewable energy is undoubtedly a cause for concern amongst many experts, business owners and industry leaders.

Conversely, waste heat recovery overcomes these challenges due to its non-reliance on climatic conditions. As a result, heat power can be used instead or in conjunction with other renewables to increase the reliability of green energy, safeguard a sustainable future and facilitate the transition to net zero. 

Want to learn more? Find out how Climeon’s Heat Power System can work for you. Talk to the team today.