The local government said the contract for the fourth and final phase went to Chinese conglomerate Shanghai Electric and ACWA Power of Saudi Arabia.
The solar park named after Dubai's ruler, Sheikh Mohammed bin Rashed Al-Maktoum, went online in 2013 and the final phase is to be launched in stages from 2020, bringing the overall cost to USD 13.6 billion.
Dubai, which has dwindling oil reserves unlike Abu Dhabi, a fellow member of the United Arab Emirates (UAE), has set a target of 2050 to produce 75 percent of its electricity needs from renewable energy sources.
The UAE has announced it plans to invest a total of USD 163 billion in projects aimed at supplying the country with almost half of its energy needs from renewable sources.