Six years. That’s roughly the gap, on current form, between an onshore wind farm getting a connection agreement from a transmission network service provider and an offshore project doing the same thing anywhere in Australian waters. Not six years to build – six years just to get from a declared zone to a signed connection offer. That number tells you almost everything about where this comparison actually sits, and it’s why I get twitchy every time a developer’s investor deck leads with megawatt totals instead of connection status.
The turbine count is not the story #
Every offshore wind briefing I’ve sat through in the last eighteen months opens with a number designed to impress: enough turbines to power however many hundred thousand homes, a nameplate capacity that dwarfs anything onshore. It’s spruiking, mostly. The number that actually matters is the one buried three slides later, if it’s there at all – whether AEMO or the relevant transmission business has issued a connection agreement, and what queue position the project holds. Onshore wind in Australia has been through this exact hype cycle already, repeatedly, and the projects that got built were rarely the ones with the flashiest render. They were the ones with a signed land access agreement, a functioning connection point, and a proponent who’d already dealt with the local council overlay.
Onshore wind: mature technology, immature queue #
Onshore is the incumbent for good reason. Turbines have been going up in Australia since the late 1990s, the supply chain is known, and the civil works (access roads, hardstands, underground cabling) are a solved problem in a way offshore simply isn’t yet. The bottleneck now isn’t the turbine, it’s the wire. Renewable Energy Zones in NSW, Victoria and Queensland are meant to solve exactly this by pre-building the transmission backbone ahead of generation, but the rollout has been slower than the state energy departments originally promised, and I’ve covered the REZ pushback often enough to know landholder negotiation and local opposition can add years even after a project clears planning.
The other onshore reality is that the easy sites are mostly taken. New England, the Hunter, parts of South Australia’s mid-north – good wind resource close to existing transmission is a finite list, and what’s left tends to need either a long transmission spur or a fight with a REZ queue that’s already crowded. None of that kills onshore wind. It just means the next tranche of projects are marginal in a way the first tranche wasn’t, and financiers are pricing that in.
Offshore wind: the zones exist, the megawatts mostly don’t yet #
The federal government has declared offshore wind zones off Gippsland, the Hunter, the Illawarra, southern Victoria’s other reaches and Bass Strait’s northern coast, under the Offshore Electricity Infrastructure Act 2021 administered through the Department of Climate Change, Energy, the Environment and Water. Declaring a zone is not the same as building a turbine in it. It’s a licence to apply for a feasibility licence, which is a licence to do years of metocean and geotechnical survey work before anyone lodges a commercial development application. Star of the South in Gippsland is the furthest advanced project in the country and it’s still working through that sequence. BlueFloat Energy’s proposed project off the Illawarra has been through its own version of the same grind, and I’d note, because this is the bit that actually determines whether steel goes in the water – that none of the declared-zone projects around the country currently hold a firm transmission connection agreement of the kind onshore proponents routinely secure within a couple of years of site identification.
That’s not a criticism of the developers. Offshore wind connection is genuinely harder: you’re talking subsea cabling, onshore converter stations, and in most of the proposed NSW and Victorian zones, landfall points that need their own planning approval separate from the offshore lease. It’s a longer, more expensive queue by design. But it means anyone comparing onshore and offshore on installed-capacity potential alone is comparing a grid connection that mostly exists to one that mostly doesn’t.
Fixed-bottom versus floating changes the maths again #
Most of Australia’s continental shelf drops away quickly, which rules out fixed-bottom turbines – the cheaper, more established technology used across most of the North Sea – for a good chunk of our best wind resource. Gippsland has workable fixed-bottom depths close to shore. Much of the rest of the coastline, including a fair slice of the Illawarra and Hunter zones, needs floating platforms, which is a technology still scaling up globally rather than one with a long Australian or even broad international track record at commercial size. I went through the fixed-bottom-versus-floating trade-off properly in an earlier piece on the two technologies, and the short of it is that floating adds cost and schedule risk on top of an already slow connection queue. That compounding is the single biggest reason offshore timelines in Australia keep sliding right, project by project, announcement by announcement.
Cost, capacity factor and the argument nobody wants to finish #
Offshore wind’s genuine advantage is capacity factor: turbines out at sea catch steadier, stronger wind than most onshore sites, and larger turbines are viable because there’s no road transport limit on blade length. CSIRO’s GenCost work has consistently shown offshore wind coming in at a higher capital cost per megawatt than onshore, sometimes by a wide margin, even before you load in the connection infrastructure. AEMO’s Integrated System Plan still has a role for offshore wind out toward 2040, particularly to firm supply near southern load centres as coal retires, but its own modelling treats offshore capacity as arriving later and in smaller volumes than onshore or utility solar over the next decade. You can read that document straight off AEMO’s ISP page – it’s public, and it’s the single most useful document for cutting through developer spin on either technology.
My honestly mildly contrarian view, having watched two rounds of offshore wind announcements now: I don’t think a single offshore turbine in Australia produces exportable power before the early 2030s, and I’d bet on Gippsland getting there well before any NSW zone does, purely because the connection and depth problems are smaller. Anyone underwriting a decade-out energy plan around large-scale Illawarra or Hunter offshore capacity arriving on today’s stated timelines is, in my view, planning around a render rather than a connection agreement.
Who actually gets built first #
Onshore wins this race almost by default over the next five years, not because it’s a superior technology but because the hard problems (land tenure, connection points, turbine supply) are largely solved ones, even if REZ transmission is running behind schedule. The Capacity Investment Scheme is underwriting a decent slug of that onshore pipeline right now, and I’ve laid out how that scheme actually allocates risk if you want the mechanics. Offshore wind is a real part of the 2035-and-beyond generation mix on paper, and the resource is genuinely excellent in places like Bass Strait. But treating it as a near-term substitute for onshore, gas peaking or batteries misreads where the connection queue actually sits today. For the fuller build-out picture across both technologies, our earlier comparison piece is worth reading alongside this one: the gap between the two hasn’t closed, it’s arguably widened.
A Newcastle postscript #
I did an early swim off Merewether last weekend, the kind where the wind’s still onshore and cold enough to make you regret the whole idea within about four strokes, and got talking to a bloke on the beach who does subsea survey work out of the Hunter for one of the offshore proponents. His read, off the record and over a coffee rather than a briefing, was blunter than anything in a press release: the seabed work is the easy part, the landfall approval is where projects actually stall. That matches everything I’ve seen on paper. Onshore wind doesn’t need a landfall. That, more than turbine size or capacity factor, is the whole ballgame right now.
– Callum Hayes, Wind & Offshore Correspondent
Photo by Hc Digital on Unsplash