A Fellow of the Institute of Chartered Accountants in England and Wales and former chair of the Isle of Man Society of Chartered Accountants, has written to every MHK and MLC with a stark warning about the proposed Mooir Vannin wind farm. He says the Island’s largest ever infrastructure project may be built on financial assumptions that simply don’t hold water.
David Owens FCA says he has “no financial interest directly or indirectly” in the Mooir Vannin offshore windfarm. But he also says the project’s implications will stretch “far beyond the present generation” and that the public and politicians are being asked to make decisions without the full facts.
His 15‑section report, sent to Tynwald members is rather blunt: the project’s forecast Treasury revenue is highly uncertain, potentially overstated, and exposed to multiple high‑risk assumptions.
A Project Built on Optimism – Not Evidence
Owens’ central criticism is clear: neither Ørsted nor Treasury have disclosed the assumptions behind their headline revenue figures.
Ørsted claims the Isle of Man ‘could’ receive £2.4bn nominal over 35 years. Treasury modelling suggests £0.7bn–£1.9bn in real terms. But Owens says the underlying assumptions are either unverified, optimistic, or contradicted by industry benchmarks.
He writes: “At present, the available information does not permit proper assessment of the potential financial benefit to the Island.”
The Risks – All High
Owens’ damning report reads like a checklist of red flags. Among the most serious:
Operating life inflated
Ørsted and Treasury assume a 35‑year life. DENZ says 30 years. IEC standards say 25 years offshore. Owens warns: “Reducing the assumed operating life… substantially reduces forecast Treasury revenue.”
Load factors too optimistic
Forecasts assume 50–47% average output. Ørsted’s own fleet averages 42%. Recent studies show turbine degradation up to 0.72% per year. Owens: “Forecast load factors exceed the best‑case degradation outcome.”
Strike price only guaranteed for 20 years
Forecasts assume CfD pricing for 30–35 years. Ørsted itself says revenue will fall “in year 21.”
Transmission charges unknown and politically set
Annual UK TNUoS charges could be £70–£140m, entirely outside Manx control.
Decommissioning guarantee weak
No escrow. No insurance. Just a parent company guarantee which Owens says carries “very high” risk.
Corporate tax residence could be challenged
Given Ørsted’s group structure, HMRC or Danish authorities could argue Mooir Vannin profits are taxable in their jurisdiction. Owens: “It is difficult to imagine that Mooir Vannin will be fully managed and controlled in the Isle of Man.”
Why This Matters Now
Owens says he prepared the report because the Island is being asked to make generational decisions without full disclosure. He stresses that the public cannot form a properly informed view either for or against, until the assumptions behind the £2.4bn headline figure are laid bare.
His decision to send the report directly to all MHKs and MLCs is deliberate: a call for transparency, scrutiny, and realism before the Island commits to a project of unprecedented scale.
The Bottom Line: High Risk, Unverified, Implausible
Owens’ message to Tynwald is clear: The Mooir Vannin windfarm may still deliver value – but the current forecasts are built on assumptions that are high‑risk, unverified, and in some cases implausible.
For a project of this magnitude, optimism isn’t enough. Owens wants evidence. And he wants politicians to demand it.
