John Kerry visited Abu Dhabi's Noor solar park on Saturday, on the first day of a trip to the Emirates.
The special presidential envoy for climate was given a helicopter tour of the facility, which is the largest single-site solar park in the world.
An image was shared by the office of the UAE special envoy for climate change, Dr Sultan Al Jaber, who accompanied Mr Kerry.
"This project enables the UAE to reach ambitious renewable energy goals," his office wrote.
Mr Kerry was later shown another major solar development, Shams 1, south of Zayed City in Al Dhafra.
On Sunday, Mr Kerry will attend high-level discussions on advancing global action to halt climate change at the GCC and Mena Regional Dialogue For Climate Action in Abu Dhabi.
This is his first visit to the Middle East since being appointed to the role by US President Joe Biden.
Mr Kerry vowed to swiftly make up for America's "lost years" in the fight to protect the environment.
The UAE has ambitious plans to rapidly increase the amount of energy it generates from renewable sources.
At the end of 2020, the country's renewable capacity reached 2.3 gigawatts.
That is forecast to leap to 9 gigawatts by 2025.
Alongside the Noor solar facility, which began generating power in 2019, there are four new projects that will drive this growth.
The biggest is the 2GW Al Dhafra solar scheme in Abu Dhabi, located 50km outside the capital.
That facility is expected to become fully operational in 2022 and would generate enough electricity for about 160,000 homes.
Dubai currently has more than 1gigawatt of installed capacity – all of which comes from three phases at Mohammed bin Rashid Solar Park.
Kerry to rally global action on climate
Kerry is leading efforts to get countries to commit themselves to reduce greenhouse gas emissions to zero by about the middle of the century.
President Biden has called a summit of 40 leaders including India and China on April 22-23.
Later this year world leaders will gather for the United Nations climate summit in Glasgow to build on a 2015 Paris accord to halt the increase in global temperatures at levels that would avoid the worst impacts of climate change.
"Looking forward to meaningful discussions with friends in the Emirates, India, and Bangladesh on how to tackle the climate crisis," Mr Kerry tweeted before he arrived in Abu Dhabi.
India says it will not only stick to the Paris accord to reduce its carbon footprint by 33-35 per cent from its 2005 levels by 2030, but will likely exceed those goals as it ramps up use of renewable energy.