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Oxford University’s Our World in Data falls for renewables industry spin

Press Release
Campaigning group Net Zero Watch has called on Oxford University’s Our World in Data (OWID) site to withdraw its webpage on the cost of renewable energy.

In a letter to OWID’s director Max Roser, NZW’s Andrew Montford explains that the site is putting its reputation at risk by ignoring the highly transparent UK data in favour of numbers that are not replicable, and most likely to be based on “hearsay”.

Mr Montford said:

The UK is almost unique in having a high penetration of renewable energy and freely available financial accounts data. A series of reviews of this information confirms that the cost of offshore wind power is high, and hardly coming down at all. It is hard to comprehend why Our World in Data would ignore this hard data in favour of unsubstantiated spin from the renewables industry. Their page on the subject should be revised before anyone else is misled.”


From: Andrew Montford

To: Dr Max Roser

11 May 2023

Dear Dr Roser

Our World in Data (OWID) is usually a rather reliable source of information, so I wanted to draw your attention to what I believe is an uncharacteristically flawed article on your website. This is ‘Why did renewables become so cheap so fast?’, which examines the levelised cost of renewable energy.

Firstly, I should point out that the levelised cost of electricity (LCOE) isn’t actually data at all. In simple terms, LCOE divides the lifetime costs of a generator by its lifetime output, but neither of those figures are known until the generator closes down at the end of its life. So while the Capital Expenditures (capex) element of lifetime cost is knowable at the start, the lifetime Operational Expenditure (opex) and the output have to be modelled. So whether a site called Our World in Data should be discussing LCOE at all is worthy of consideration.

Where LCOE is discussed, the data used as input needs to be grounded in reality, the modelling assumptions need to be made clear, and caveats spelled out. This is not the case for the sources you cite. For example, while widely cited, the assumptions used by Lazard are demonstrably false. For example, for offshore wind, the version of the report you cite (version 13) claims a capital cost of £2.3-$3.5m/MW, roughly half the cost of offshore windfarms in the UK, and a third of the cost of the only (admittedly experimental) offshore windfarm in the US. As I have pointed out elsewhere, the assumptions for capacity factor and opex are similarly divorced from reality.

You also cite the International Renewable Energy Agency (IRENA), whose figures are similarly problematic, notably because they convert all their numbers into US dollars, giving them a large and entirely spurious downwards trend as a result of the appreciation of the dollar against most other currencies.

It’s not clear where Lazard and IRENA are getting their input figures from, but it’s unlikely to be anything that could reasonably be called ‘data’. IRENA is supposed to be global in nature, and Lazard are vague about whether their estimates are for the US or for the world. Either way, the majority of the financial inputs cannot be data because such information is not available for most of the world: word of mouth and/or developer announcements seem the most likely sources. In the UK, developer announcements are typically 15-20% lower than outturn cost.

The clear exception to this rule is the UK, where financial data is freely available for all offshore windfarms and many large onshore ones (as well as a few solar parks). This then is the only reliable data for estimating the levelised cost of renewable energy. I refer you to the paper by Aldersey-Williams et al. (2019) on the LCOE of offshore wind, which presents a very different story to the one in your article, and which has been replicated by others.

By basing your article on figures that can only be based on hearsay, rather than on empirical data, you are risking your hard-won reputation as a reliable source. I would advise you to revise the article accordingly.

With best regards

Andrew Montford
Director, Net Zero Watch