An autonomous window-washing drone landed 19-year-old Sydney resident Oliver Nicholls the top US$75,000 (A$99,850) Gordon E Moore prize at this year's Intel International Science and Engineering Fair.

The drone device is tethered to the roof of a commercial building.

It is equipped with a powerful spray nozzle and rotating brushes.

Nicholls' drone can handle 45 kph winds, and costs just over A$3000.

It is said to replace human teams that can cost in excess of A$14,600 per building and in the process reduce the high risk of injuries, Intel said in a statement.

The winning entry was selected from a total of 1800 young engineers and scientists taking part in 420 affiliate fairs in 81 countries and territories.

Of these, 600 made it to the finals, and 24 selected as best in category.