The money was announced this week by the U.S. Department of Transportation as part of $527.8 million in grants to airports across the country.
London is at the top of the list of destinations, but the airport is also looking into Paris, Frankfort or Amsterdam.
Duke Energy is leasing ground from Crane for the solar farm that includes about 76,000 panels.
Officials are trying to stir up interest from airlines in providing direct flights between Indianapolis and London.
The Indianapolis International Airport has received this honor four of the past five years.
More than 76,000 solar panels went online last Friday, albeit six months behind schedule.
The Indianapolis International Airport will soon be home to the largest airport-based solar farm in the world, with the addition of panels that track the sun.
The Indianapolis Airport has 18 parcels of land that add up to about 1,200 acres available for lease or sale on the airport property.
The Indianapolis International Airport Authority voted today to expand its smoking ban to include e-cigarettes.
The rating comes from the Airports International Council, which ranks airports by region based on passenger satisfaction surveys.