When Hitachi came in to buy Wylfa Newydd from German energy giants Germany's E.On and RWE in 2012 then PM David Cameron described it as a "multi-billion pound vote of confidence in the 海角视频".
It was a huge boost to the island that a global brand with the stature of Hitachi was prepared to invest.
The sale price for Wylfa Newydd and Oldbury in Gloucestershire was around £700m - a major commitment from the start from the Japanese multi-national.
They started to build up a strong team at investment vehicle Horizon Nuclear Power - with big hitters in the industry like Duncan Hawthorne, Gwen Parry-Jones and former Wylfa site director Greg Evans brought in.
But eight years after riding in as saviours Hitachi has now departed the scene - leaving behind disappointment and having burnt through at least £2bn.
Business Live has spoken to a number of sources at the heart of the development about what went wrong.
Flawed from the start?
When Tony Blair first began the process of expanding Britain’s nuclear energy portfolio in 2006 - the message from Government was clear.
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While they wanted a new fleet of 10 nuclear stations - including at Wylfa - taxpayers were not going to foot the bill. This was going to be left to the private sector to deal with.
But a source said that all across the world it is Governments that are directly involved in developing nuclear plants - for example in France the French state backed power giant EDF both builds and operates its nuclear stations.
There is a reason for this.
The huge upfront costs and long pay back time for nuclear makes it a hard sell to private investors - who are looking for a quicker turnaround on their investment.
Strike price
Over the years Governments have tried to find ways of making investment in new nuclear an attractive and secure proposition - without breaking their pledge of no direct subsidies from the public sector.
This saw them develop the 'strike price'.
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The nuclear strike price refers to the price the government will guarantee per unit of electricity produced.
But when it struck its agreement with EDF in 2016 for proposed new nuclear reactors at Hinkley in Somerset - the strike price of £92.50 per megawatt hour (Mwh) came in for fierce criticism.
At the time the wholesale price of electricity was about £44/Mwh.
But this was cheaper than offshore wind at the time.
The message for Hitachi and Horizon after this was clear - any future strike price would have to be lower, even though the company was taking the same financial risk as EDF.
The strike price eventually offered to Hitachi in 2019 was £75/Mwh - meaning over the years billions of pounds less in return on the investment.
海角视频 Government said this reflected the significant fall in the cost of renewables over this period.
Uncertainty
Since Hitachi first made its investment in 海角视频 nuclear it is fair to say the political climate in the 海角视频 has been fairly tumultuous.
Brexit has upset the usual political stability in the 海角视频 with three General Elections in four years and the 海角视频 still unsure what the future trading position with the EU - and much of the rest of the world - will be.
A source added: "Brexit has been a concern, it has also been a distraction for the politcians. We were told legislation is being held up because ministers are focused on Brexit. We have also had changes in Government.
"Then there are potential issues like free movement of workers and tariffs - a lot of uncertainty."
Throw in Covid and there is a whole new level of global economic uncertainty to deal with.
In its announcement about withdrawing, Hitachi said the "investment environment has become increasingly severe due to the impact of Covid-19”.
Trust in Horizon Nuclear Power
One source said: "Horizon is a development company with no track record in nuclear construction, commissioning or operations.
"Building this capability from scratch in a nuclear context is a huge task, riddled with risk and uncertainty for investors.
"At the same time Hitachi is a nuclear equipment manufacturer with no experience of long term operations as a utility."
They said this made the Government wary about whether the scheme was deliverable on the price and timescales being proposed.
They added: "The killer reason, in my view is this. If you are government looking to invest circa £20bn in a first of a kind nuclear development, why Horizon?"
Political will
'Warm words' is how one source described the 海角视频 Government approach but complained this had not been followed with action to make the investments happen.
Wylfa Newydd is not the only 海角视频 nuclear project that has been scrapped or faces an uncertain future - showing this is a wider problem than one site or one company.
A source also criticised the delay in getting a decision on the Development Consent Order. Submitted in June 2019 - the original deadline for a decision from the BEIS Secretary of State was October 23.
This was pushed back to March 31 due to issues raised by planning inspectors - although sources believe these could have been addressed if flagged earlier.
The date was then moved to September 30 but Hitachi has now played its final hand ahead of any decision.
Then there is the Energy White Paper which was originally due for publication in summer 2019 when it was expected a new funding model for nuclear would be announced.
The paper is still not out and is now scheduled for autumn.
We'll never know what difference these delays could have had on Hitachi's final decision.
In the 海角视频 Government's defence a source said the offer prior to suspending the project in January 2019 was a good package - with the Government offering to take a stake in the project alongside the strike price offer.
Combination of factors
Sources agree there is no single factor that has once again dashed hopes of a new generation of nuclear investment.
One said: "While we have focused on the major impact on the local economy people don't appreciate how big this is in international terms. This is a geo-political issue."
While various project costs have been knocked around sources say £16bn is probably the best estimate.
A source added: "This is a huge investment, even for a company as big as Hitachi.
"When they announced the were suspending the project their share price went up, this tells you what the markets thought about this.
"They wanted to share that risk but the investors were not there.
"At the end of the day for many reasons they decided the risk was just too great."