Explainer: Why are wind turbines so big – and could smaller be better?

Everything is bigger in Texas, the saying goes, but for one thing: wind turbines. 

Texas is the US wind capital with three times more working turbines than the next largest US wind state, Iowa.

But, notwithstanding a handful of giants, the machines are as low-slung as the state’s archetypal cowboy jeans.

Texas’ great plains, hill country and deserts are covered in many, many short wind turbines, thanks to a rush of development in the two decades before 2021, when wind turbines in general were much smaller than they are now.

It has 19,175 in total, with an average hub height of just 85m and an average tip height of 132 metres, according to 2025 data from the USGS. 

In Australia, the trend is going in the opposite direction. Project developers are opting for bigger and bigger turbines, in a bid to reduce project footprints – and impact on the environment – while generating maximum power, and that’s because of what is made available by suppliers.

But which approach is better: Fewer, much taller machines with massive windswept areas, or lots of small turbines that crowd the project area but can’t been seen from as far away?

According to the experts, pushing for the biggest machine possible hasn’t always worked in developers’ favour in terms of social licence.

In western Victoria, Neoen’s proposed Kentbruck wind farm is the latest example of how turbine height can divide communities, as riled residents and holiday home owners share images comparing the future turbines with one of Melbourne’s tallest building, the Rialto Tower.

But if smaller turbines are what some communities want, why can’t Australia be more like Texas? 

In short, rules and money.

In Texas, during its heyday in the 2000s, wind energy was cheap, and turbines were structurally smaller. It became the wind state thanks to a “lack of regulation”, zero environmental requirements, and the availability of vast swathes of deserted land where noise limits don’t apply, according to a 2018 article published in the Inquiries journal.

Australia, on the other hand, has rules – and many of them. When combined with the laws of physics, the battle for sites, and environmental and community expectations, the value of a kilowatt is much higher here than in Texas – and that means going bigger.

Giants among us

In the earliest days of wind, Aussie turbines were relatively small. 

On King Island in 1998, three of the earliest wind towers only generate 250 kilowatts each and have a 30m hub height. 

Today, the biggest turbines have hub heights of 166m, tip heights up to 236m and power ratings of up to 7.2MW.

These behemoths can be seen in Queensland where wind speeds are lower, says Vestas’ Michael Brown, such as in Wambo where the biggest turbines yet are set to go up.

Across Australia turbine hub heights average at around 150m, and slightly lower in Western Australia at 125m where wind speeds are higher, he says. 

But for future projects, 8MW is what developers are tacitly proposing in their planning applications with turbines that are closing in on 300m at their tallest point.

The trade off

Behind the great Australia wind turbine inflation is a trade off: communities want to be adequately recompensed for hosting, no one wants large-scale environmental damage, neighbours don’t want turbines on their doorstep – large or small – and governments want to manage who is connecting to the grid, where and how. 

But at some point, wind farms need to make money. 

This tension has led to bigger turbines that can wring more megawatt hours from fewer machines, says Engie head of development Scott de Keizer. 

“One larger turbine is more expensive than one smaller turbine but still cheaper than two smaller turbines that produce the same amount of megawatts,” he told Renew Economy.

“Australia is notoriously hard to get environmental approvals, and so we also have to consider the footprint of the project… alongside the additional impact of larger rotors which have greater visual impact and bird and bat interaction. 

“In general, based on the LCOE [levelised cost of energy] analysis of projects we are developing, more, smaller turbines result in higher cost wind farms which are lower yielding and therefore have no chance of making it economic in today’s competitive environment.” 

Former Mint Renewables CEO Peter Cowling has been working on wind projects almost since the industry began. He says developers have flirted with small turbines in the past, but none have been able to make the financials work.

And it’s the financials that must also work for the communities that host wind farms, as they will be the recipients of some of the benefits. 

A project that is more economically productive is better able to support its host community, says farmer and Stride Renewables consultant Luke Osborne.

“The industry has a strong desire to get the lowest cost of energy, which is great for the community and turbines getting bigger has been a big factor in that,” he told Renew Economy. 

“Within reason, I’d probably lean towards the best project with the fewest turbines and the best shared benefits program, over a marginally lower visual impact and less economic project. I think everyone is poorer for that.”

Still competing with fossil fuels

Another quirk of Australia’s fraught relationship with wind is the pressure to make renewables equivalent to fossil energy – and that means longer life spans.

The design life of a wind turbine is typically 20-25 years. But today wind farms are expected to last for 30 – and preferably more – years.

This requires machines to be over-engineered for the expected conditions, notes Aurecon in its 2023 costs and technical parameter review for the Australian Energy Market Operator (AEMO).

Finally, with the best sites already taken, bigger blades are needed to capture energy from medium (7.5 to 8.5 m/s) and low (6.5 to 7.5 m/s) wind speeds.

“Smaller turbine rotors cannot compete with the larger turbine rotors anymore. Hence, OEMs don’t offer turbines with smaller rotors than 160m. The smallest wind farm delivered in the last few years is [Ark Energy’s] Rye Park [in New South Wales], and that has a Vestas machine with a 162m rotor,” de Keizer says.

Shrinkage

But sometimes turbines don’t need to be so big: developers often ask for the maximum possible number and size of machines to give them wiggle room if communities or regulators demand something smaller. 

Community feedback is thought to be behind Neoen’s move to cut the height of turbines at its Tchelery wind farm in NSW by 15m. 

In 2023, Acen Australia reduced the size of the turbines at its controversial Robbins Island project from a maximum tip height of 270m down to 212m. 

Tilt Renewables tried to supersize its Liverpool Range project in 2022 from 962MW to 1.33GW but massive resistance saw it scale the capacity back to 1GW and tip heights down from 250m to 215m.

The Kentbruck conundrum

The residents of Portland, Victoria, are familiar with wind farms. 

Coddrington is the country’s oldest currently operating commercial wind farm, according to owner Pacific Blue, and turbines line the coast. 

The region is set to look out on the second designated offshore wind zone, dubbed the Southern Ocean, and developer Neoen is proposing the Kentbruck wind farm. 

It’s a 600MW project with up to 105 wind turbines that, at 270m at their highest tip, will tower above a commercial pine plantation along the notoriously windy Discovery Bay, between Nelson to the west and Portland to the southeast. 

The sheer size of the turbines are causing the Portland and Nelson communities to mobilise against the project, according to local resident Mary Picard, who is concerned that ever taller turbines are creating unnecessary opposition to wind farms. 

“What worries me is that younger environmental activists are opposing these sorts of things on environmental grounds because they don’t have enough trust that these things can be done without harm,” Picard told Renew Economy.

“Why do these things have to be so big?”

In this case, blame the trees, Cowling says.

Surfaces such as the ground, trees, and buildings create friction which slows wind speeds, a phenomenon called wind shear. 

“You must have a very high hub height because you’ve got to get up above the trees and as high above the trees as you can because the wind shear will be extreme,” he told Renew Economy.

“It’s being actively slowed by the trees… then the higher you go the more of that wind you get.”

A statement from Neoen notes that most existing wind turbines in Australia have a blade tip that at its lowest point is just 20m-35m above the ground – not ideal for working in a forest. 

“The minimum blade-tip height of the Kentbruck turbines has been adjusted to sit at 60 metres above ground. This follows careful study and consideration of the local avifauna and will help protect the native bird and bat species that forage in the area,” the statement says.

“The Southern Bent-wing Bat, for example, most frequently flies at heights below 60 metres.”

Larger wind turbines are coming for Australia, as developers try to match size against what price their project will need to be able to sell electricity at to make money.

But greater and greater heights are also likely to make wind energy, already difficult to navigate through state and federal planning and environmental processes, even more of a flash point.

And if communities do get their wish – to have more, smaller turbines – the question they will have to face is whether they are prepared for a trade off between height, or even higher power prices and a deeper impact on the environment they live in.