In October, Facebook announced it was to buy power from 200MW of the project in northeast Nebraska to power its Papillion data centre also being built in the state.
As part of the expanded deal, Facebook will continue to buy power from 200MW of the project when it starts operations however, this will gradually increase to the full 320MW output by 2029.
This follows Facebook's decision to increase size of the data centre.
In the meantime, Adobe will purchase power from 10MW of the site between 2019 and 2028.
The site, acquired by Enel's North America business unit from developer Tradewind Energy, is currently under construction and due online by the end of the year.
It is due to be powered using Nordex Acciona turbines, according to Windpower Intelligence.