If it’s 24-hour power we need, wind is way ahead of solar. But can these giant propellers fill most of the gap left by 23GW of coal power that needs to leave the NEM? Jeremy Chunn reports.

As solar is added on rooftops across the country it creates a problem, simply because PV systems powered by the sun generate between the morning and afternoon peaks. The “duck curve” – a hollowing out of daytime demand as volumes of PV have been connected to the grid over the past 10 years – has left a steeper and steeper ramp up to evening peak to be supplied by coal and gas.

Many of those fossil-fuel assets are getting very old and clunky. How long will they be able to take the strain?

As clean energy generation has been added to the National Electricity Market solar and wind have started to push the dominant energy source, coal, slowly to the sidelines.

In 2006, coal met 86% of demand on the NEM (black coal 59%, brown coal 28%). Solar and wind barely registered back then, according to data from OpenNEM. By 2019, a renewables build-out that started in 2008 and quickly gathered pace had made an impact on supply: coal was fulfilling 68% of load, with utility-scale and rooftop solar making up 7.6% and wind 8.2%.

If it’s 24-hour power we need, wind is way ahead of solar. But how much should we expect of it? There are currently about 6.9GW of wind assets generating, less than one third of the 23GW output of coal plant across the country. There is still a long way to go. Can wind fill the gap?

Follow a winding road

The wind industry is in little doubt that tens of gigawatts of additional wind energy can, and should, be added in Australia. “There is a massive opportunity for the industry over the next 10, 20, 30 years to continue to deploy many thousands of megawatts of wind and other technology,” says Tilt Renewables executive general manager renewable development Clayton Delmarter. “Many times more than today’s amount.”

Different regions have different wind profiles, but Delmarter says it’s too hopeful to expect a geographically diverse distribution of wind plant to deliver anything equivalent to a reliable output. How solar and wind will be matched with storage – batteries, pumped hydro – and firming assets to balance intermittency isn’t entirely clear, “but we know for sure that firming and storage capacity are going to be vital to continuing to deploy more renewables into the system,” Delmarter says.

“We try to take advantage of that in our own portfolio to try to reduce out exposure to seasonality and climatic conditions and highly correlated on-off production and revenue risk, but you can only do that to a limited degree,” he says. “There will always be correlation and there will always be times when there is no wind and other things you have to deal with on the system.”

Land of the giants

When GE head of sales Australia and New Zealand onshore wind David Lian started in the industry about 12 years ago he remembers 88m-diameter rotors powering 2MW machines. Today, GE’s Cypress turbine measures 158m across and is rated 5.5MW – an 80% wider blade span taking in an area about 3.2 times larger and delivering 2.75 times the power. “The market is constantly evolving,” Lian says. “On the scale of iphone releases you’re getting turbine rotor diameter increase of 5-10m. It’s quite extraordinary.”

One of the main constraints around blade length for onshore wind locations is transportation, Lian says, where truck drivers hauling ludicrously long loads pull off amazing feats of cornering to ensure these things get built. But there has to be a limit. “Victoria is flatter with large highways, so it’s a little less of an issue there, but in many parts of the country winding roads pose a significant restraint.”

A canny solution developed by GE has been the split blade, transported in two pieces. The blades on the Cypress units include a root section, no longer than a typical blade sold in the past two years, and a tip. “We’re sticking to a generally established norm for blade transport based on the previous generation of turbine and then we’re able to extend the blade by installing the tip onsite,” Lian says.

Further afield

As turbines go higher to capture higher wind speeds and come with longer blades to generate more energy, sites in NSW and Queensland that might have been deemed uneconomic only a few years ago are today as competitive as some of the older sites in South Australia and western Victoria with higher wind speeds. “That’s been the big shift,” says Delmarter at Tilt.

Tilt can today procure new technology capable of about 10 times the output of units at some of its projects that are up to 20 years old. “You’re talking 6MW-plus onshore generation with rotor sizes up to 170 metres,” he says. “The amount of energy they can capture and produce on a per-turbine basis has increased absolutely massively.” The result is falling operational and construction costs.

Ten years ago a typical viable site might have a wind speed of 8.5 metres per second, says Lian at GE. “But now you’re getting wind farms with a 7.5m/s average wind speed, or even lower, becoming viable in places like NSW.”

The key issue that’s emerged for the sector in the past couple of years is access to the grid, Delmarter says.

Repowering ahead

Wind projects involve long lead times, and the Australian Energy Market Operator’s Integrated System Plan (ISP) and hoped-for rule changes and infrastructure investment decisions around it – not to mention the giddying ride of political and policy uncertainty – make the business of owning projects with lifetimes up to 30 years a deep challenge. Everyone in the industry would love to know how the ISP will progress, but that’s a little too much to expect.

Within the next 20 years, of course, it will make perfect sense to return to the best locations for wind in Australia, where plants have already been built, and replace turbines with vastly more powerful machinery. This form of “repowering”, as it’s called, is already happening in Europe.

“In the past the location of wind farms has really been dependent on top-notch wind resources,” says Australian Wind Alliance national coordinator Andrew Bray. “But as the technology has developed and new designs have allowed them to capture much lower wind speeds, the number of places you can put wind farms has increased massively.”

Parts of NSW and Queensland that were out of bounds five to 10 years ago are now included on lists of viable locations for large installations, he says.

This doesn’t mean older wind plants will start to look a little embarrassed about their output relative to younger peers. A phase of “repowering” older wind farms is underway in Europe, Bray says, where old turbines are replaced with new equipment.

“The earliest [wind farms in Australia] went into the windiest spots, so if there is an option to put better kit in there and harness more of the wind then they can use the grid connections, which are often the most valuable parts of a project and carry on.”

Tilt is already seeking approvals to replace technology at sites in New Zealand where the turbines have been spinning away for about 20 years. “We’ve got some sites in Australia – and we know our competitors do too – where they’re starting to think hard about replacing technology with newer, more efficient technology,” Delmarter says. “That’s a massive opportunity for the sector … where you take what you’ve got and make it even better.”

With two-piece blades, GE’s Lian says repowering plants may be as simple as swapping out tips for longer versions – provided the turbine can withstand the mechanical load. That could be a long way off, however. Until then, the rapid evolution of wind technology means repowering will mostly involve completely removing old units, foundations included, and replacing with completely new gear. “The old technology is totally incompatible with the new,” he says. “You need to replace the entire turbine and the foundation for a repower.”

Researchers at work off the coast of Victoria, scouring the environment for data to help Star of the South put together a proposal for up to 2GW of offshore wind.

Looking offshore

An offshore plant can be larger than onshore without the bother of negotiating with landowners. The site for the Star of the South project has been chosen for its strong wind, whipping through the Bass Strait off the coast of Gippsland, south-east Victoria.

The developer is monitoring wind and wave conditions near Port Albert and is optimistic about data gathered by satellite and at onshore wind farms. It’s particularly upbeat about the wind profile on very hot days when demand for electricity is at its highest. The developer of Star of the South expects to have a useful wind profile model within two years. “We’re studying the wind profile and seabed conditions off the south coast of Gippsland to help confirm the project’s feasibility and inform the initial design of the wind farm,” says Star of the South chief development officer Erin Coldham.

The seabed is within the 20-40m range that makes non-floating offshore wind possible and the plant will connect near the Latrobe Valley, with strong existing transmission. The exploration licence covers 496 square kilometres between 10 and 25km from shore, so the top halves of turbines – up to 2GW of them – would be visible at the horizon. On EcoGeneration’s calculations, a 250m tower would have to be at least 56km from shore to be hidden by the horizon for those standing on the beach.

If site investigation shows the project is feasible, and it progresses through environmental and planning approvals, the developer hopes to begin construction in the mid-2020s, possibly as early as 2023.

“It’s still early days for the project, but we’re excited about the potential to kick-start a booming offshore wind industry in Australia, creating opportunities for local jobs and investment,” Coldham says.

The developer says it has financial support from Copenhagen Infrastructure Partners, a Danish pension fund already invested in offshore wind in Taiwan and the US.

Transportation of turbine componentry is much less of a problem for offshore applications, where blades can me manufactured close to ports and shipped to site. The GE Haliade-X offshore turbine, released last year, has a rotor diameter of 220m and can turn out 12MW. Offshore machines can be installed onshore, GE’s Lian says, but they are even harder to transport and also noisier. “Those are challenges we have to solve along the way as we move to larger and larger rotors.”

The late surge in offshore wind financings last year saw the sector tick up $US29.9 billion in 2019, up 19% on 2018 and $US2 billion more than in the previous record year of 2016, on data from BloombergNEF.

Offshore projects that reached financial close in the second half of last year include a 432MW array off the Scottish coast, a 376MW project off Taiwan, a 500MW installation in the East China Sea and France’s first offshore wind project at 480MW.

“We expect the sector’s global momentum to continue in 2020, with the focus on gigawatt-scale projects in the British North Sea and the first commercial arrays off the US East Coast,” said BNEF head of wind research Tom Harries.

Across the fence

At the Australian Wind Alliance, Bray’s efforts in the wind sector are directed towards relationships and appeasement. When revenues from hosting turbines can amount to $10,000 to $15,000 a unit and more, goodwill among neighbours can fray when developers come to town. Some will be better off, some will get nothing, and others just won’t know what to make of these enormous structures seemingly cast from old science fiction movies.

“There is always going to be a range of views, but there is a general understanding that renewable energy is the way of the future and the places where there are wind and solar resources plus transmission plus wide open spaces, they realise there is an opportunity there.”

Farming and agriculture have always been risky endeavours, and the opportunity to access steady income from the generation of electricity is easily understood by communities, councils and businesses in the countryside.

Bray has heard both sides of the argument about wind. “Sometimes you land yourself in pretty sticky situations,” he says. “Not everybody wants to hear there is a wind farm planned for their area.”

Developers who exhibit expertise and commitment will have a better experience than those that don’t. If agreements with landowners are shrouded in secrecy, ill feeling may foster. “In the early days trust was not as highly valued as I think it should have been,” he says. Things are improving, however. “There is a greater level of transparency [these days], and that’s been much better for developing trust.”

The issue of how benefits are shared and real outcomes delivered to local communities will become “critical”, Bray says. “The urgent attention has gone to transmission and grid connection and what have you, and that all has to be done, but if you’ve got 34 renewable energy zones around the country and you’re going to start loading a whole lot of new projects into them and they’re not well-received, that’s going to cause problems pretty soon.

“It’s one of those very foreseeable issues,” he says. “As long as we act on it and get ready to deal with it, we’ll be alright. If we don’t, it will be a real risk.”

Bray’s tips for getting it right with communities are: engage early, engage often, engage as widely as possible, be transparent on plans, deliver tangible benefits for the community, such as local jobs and prioritizing local suppliers, allow for community investment and “look after the neighbours”.