A Guardian investigation has examined a series of massive AI investments announced by the government over the past two years, comparing what was promised with what has so far been delivered.

The investigation centres on two companies backed by the chipmaker Nvidia and central to the UK’s AI plans, Nscale and CoreWeave.

It has found that large, promised sums do not represent real investments into the UK’s economy, that new datacentres are not in fact new, and that a giant supercomputer set to be online later this year is still being used by a construction company in Essex.

Here are some of the key details at a glance.

A supercomputer centre set to be built this year is still a scaffolding yard in Loughton

The Guardian visited a site in Essex that is supposed to host “one of the most powerful AI computing centres ever built”, built by Nscale. The government and Nscale say this supercomputer is supposed to be up by the end of this year.

The site is still being used as a scaffolding yard by a different company. While Nscale said more than a year ago that it had already bought the site, land records seem to show that it is not registered as the owner of the land. Nscale is very unlikely to finish constructing a “top tier” supercomputer there this year.

The UK government has not checked the numbers when it comes to massive AI investments

The Guardian asked the government about key investments worth billions of pounds, including from Nscale and CoreWeave. The government said that these numbers came from the companies themselves, and that it had no mechanism in place to audit them. It could not say what these investments involved: equipment, capital or something else.

Asked about a contract it said had been signed to build the supercomputer in Loughton, the government did not answer. Instead, it said the entire related investment, $2.5bn, did not involve a formal contract, but an intention to commit capital.

Some ‘investments’ are not money, but computer chips relocated to the UK

Nscale and CoreWeave have both indicated that a large part of their massive investments will take the form of Nvidia chips, which they will buy and place inside datacentres in the UK. From there, these chips will be rented out to users in the UK, including US tech companies.

So, for example, Nscale’s $2.5bn “investment” in the UK may in large part mean that Nscale plans to buy a massive number of chips from Nvidia – chips made in Taiwan by a US company – put these in a datacentre in the UK, and from there rent them to Microsoft.

This does not mean $2.5bn will be injected into the British economy.

As another example, in 2024, CoreWeave and the government announced a £1bn investment that, as it was described, would bring two new datacentres to the UK. CoreWeave said this would create jobs.

New datacentres were not built. Instead, CoreWeave put Nvidia chips into existing UK datacentres. It has said these chips and associated logistical and personnel costs are the bulk of its investment. This was an “industry-standard” approach, it said.

A Lanarkshire AI hub will require a nuclear reactor’s worth of power

This January, the government said that CoreWeave was going to partner with the Scottish firm DataVita to build an “AI growth zone” with between 500MW and 1GW of private wire renewable energy. CoreWeave’s investment here is £1.5bn, which, again, is not a figure the government has checked.

1GW of renewable energy is the output of an entire nuclear reactor, or of Scotland’s largest offshore windfarm, which has an area of roughly 1,100 square miles. DataVita has said this will be private wire energy; that is, it will bypass the public grid.

There are no plans on file for DataVita to build a nuclear reactor or gigantic windfarm in Lanarkshire.

Key companies have spotty records, but might make a fortune anyway

CoreWeave was one of the biggest tech IPOs of last year – with its share price nearly quadrupling in the months after its stock floated on the market, amid soaring AI rhetoric. Now, however, the company is being sued by shareholders who alleged it concealed vital information about delays in its datacentre buildout, which caused the stock to fall when the information came out.

CoreWeave said it was aware of the suit, adding that the claims were without merit and it would defend itself vigorously. Whether or not the allegations are true, some of CoreWeave’s early, pre-IPO investors are likely to have made a fortune in the months after it went public.

Nscale, meanwhile, allocated a number of its shares at a price of 1p in October. Today, after the company raised a $2bn funding round on a valuation of $14.6bn, these shares are worth many times that. An analyst who examined the figures told the Guardian: “It’s kind of a 350,000% return on investment.” Shareholders could make a fortune when Nscale does a public offering – how much depends on the AI hype at that time.