The ten-year agreement will mean power produced from Enel's 200MW Dominica wind project in San Luis Potosi, central Mexico.
Around half of HSBC's 1,100 Mexican offices and branches will be powered by clean energy, Enel said. The contract begins from the second half of 2017.
Dominica was completed in two 100MW phases in 2014 and 2015, according to Windpower Intelligence, the research and data division of Windpower Monthly.
It comprises 100 Gamesa G90 2MW turbines