However, almost a year and a half later, there has been little progress in deployment and companies are still bogged-down in regulations and red tape.
This week (5-8 December), the first Iranian Renewable Energy Commercial Conference (IRECC) is hoping to change that by bringing the world's renewable energy companies and financiers to Iran, to meet with local partners.
Iran's government is seeking 5GW of renewable energy by 2020, with more than 4GW of wind power. The nation currently has approximately 141MW of installed wind power.
"According to SUNA, the renewable energy organisation of Iran, there are already 15 wind farms operational in Iran but there's 100GW of potential capacity from wind alone," said Alex Stein, senior producer at Green Power, the company hosting IRECC.
"SUNA modelled its new feed-in tariff policy on the German equivalent. It is a sign of the country's gathering support for renewable energy that the tariff is significantly longer and at higher prices than previous years," he said.
The lack of activity has been put down to the early compliance by Iran to the conditions laid out in the nuclear deal, meaning sanctions could be lifted.
"The rest of the world wasn't ready. The process was completed six months earlier than expected in January 2016," Stein explained.
Iran has "fantastic typography for wind and the population is well educated," Stein added.
However, while the ambition is there, financing projects remains a struggle. Banks and financial institutions are wary about Iranian deals, and the risk of breaking sanctions set by the US.
In 2015, bank BNP Paribas was sentenced to pay $8.9 billion over breaches in Iran, Cuba and Sudan.
"Banks are cautiously working out how to do business in Iran," Stein said. Half a day at IRECC has been put aside to discuss financing with representatives from debt and equity finance banks.
"It will mean developers and banks will have to do more work to finance projects, but the returns are worth it," Stein said.
The US election also delayed progress of new projects. "It became clear nothing would happen before the end of the Obama administrations. From about September onwards finance activity stopped," explained Stein.
He said there was still a lot of activity from OEMs and developers. There had been many trade delegations to Iran with a renewable energy contingent.
There are even several gigawatts of shovel-ready projects waiting for finance to be arranged. More frustratingly, some shovel-ready projects, with power deals in place, have had to be canceled due to a lack of activity.
"It's about equity risk versus reward," explained Stein.
The price of the power deals in Iran are among the highest in the region, Price added, as Iran looks to expand its renewables capacity.
He said the country has a strong supply chain, with good steel tube and pipe infrastructure and there is Chinese investment in Iran's ports.
The national grid is also being upgraded so it can cope with any influx of renewables.
As a result, SUNA is looking to attract $10bn of direct private investment by 2018 and $60bn by 2025.