More than 10 years have elapsed since David Rodgers was first part of Scotland's bid to utilise its environment for a wind power revolution in the north of the UK.
Back then Mr Rodgers was embroiled in a fierce legal battle with billionaire Donald Trump, who called the planned turbines "reckless monsters" that would ruin tourism at one of his Scottish golf resorts.
Now, in his role as chairman of the Aberdeen Renewables Energy Group, Mr Rodgers has a lot to smile about.
Despite Mr Trump's objections, the £150 million project went ahead and was merely the start of Aberdeen's ambitious green energy plans.
Mr Rodgers is now involved in making Aberdeen's dream of becoming Europe's renewables capital a reality.
"I've worked in the city for 35 years," he told The National.
"I started in the civil service and I have seen how things work from both the public and private sector. I went into the energy industry in 1993 and have had a close connection with the world of energy ever since.
"I was involved in Aberdeen's first offshore wind farm. It was a new concept for the city then.
"Now I get to see first-hand how Aberdeen is building on 50 years of oil and gas heritage with its innovations and achievements and how it is delivering them."
Mr Rodgers has been at the Cop26 climate summit this week in Glasgow to showcase the region's hard work.
"I'm really proud of Aberdeen and full of hope for the future. We have developed strong wind farm credentials and we got to share that with the world at Cop26," he said.
"We have 50 years of expertise in the oil and gas industry and the world needs these skills to create these type of developments.
"My time at Cop26 has been spent conveying the ambitions and the opportunities for the north-east in the future of energy transition and what we have to offer."
His visit coincides with a new report by KPMG which cited Aberdeen's wind farm potential as being the key to Europe meeting its net zero target by 2050.
The Oil and Gas Transition survey concluded that for Europe to reach climate neutrality by 2050, it will require offshore wind capacity to increase from 23 gigawatts today to up to 450 gigawatts, with half of this capacity to be installed in the North Sea.
Aberdeen has created the world's first floating wind farm and TotalEnergies announced that the city has been chosen as a global centre for its offshore wind operations.
"We need firms to transition to be able to go into the net-zero world," Mr Rodgers said.
"A lot of companies in north-east Scotland are developing projects and the supply chain is looking to see where they can play their part. We have world-class engineers here and subsea experts here.
"We represent more than 200 companies and we reflect the ambitions and activities in the area around net zero. We promote opportunities and help to link up our members with developers.
"It takes a lot of infrastructure to deliver these big projects on the ground and we have it."
While Mr Rodgers was sharing Aberdeen's green energy potential with the world, 50 miles away Mr Trump was hosting an international delegation from Indonesia for Cop26 at his flagship Turnberry hotel in Ayrshire.
He is famed for making the US the first nation in the world to pull out of the historic Paris Agreement, a move which has seen President Joe Biden rebuild bridges with world leaders at Cop26.
Had Mr Trump's long-running legal dispute with the Scottish Government over Aberdeen's wind farms been successful, the city's future as Europe's green energy capital could have been a different story.
He had claimed the turbines would ruin the view from his nearby Balmedie golf course, north of Aberdeen.
Mr Trump said of the scheme, which launched in 2018, “with the reckless installation of these monsters, you will single-handedly have done more damage to Scotland than virtually any event in Scottish history".
When he was asked to produce evidence, he replied that he was "the evidence".
“I am an expert in tourism, I am considered a world-class expert in tourism so when you say ‘where is the evidence?’ – I am the evidence.”
The wind farms were approved and Mr Trump spent years suing the Scottish government, taking his fight to the UK's highest court until his case was thrown out and he was ordered to pay the government £225,000.
On the edge of Scotland's west coast, his Turnberry hotel and golf course is three miles from another proposed wind farm, to which he also objected.
These so-called “monsters” off Aberdeen Bay are now permanent structures on its skyline, offering a lifeline of work and a future to thousands.
As Mr Rodgers relayed their potential at Cop26, he hopes the world will learn from the work Aberdeen is doing.
"Cop26 has been a tremendous gathering of world leaders and international government representatives," he said.
"The world is really watching for the blueprint of the planet that will emerge. I hope Aberdeen's work will play a part."