Stolaroff and his colleagues spent three years studying the environmental difference between quad copters, a type of drone and diesel-powered delivery trucks in the US. In new research published in Nature Communications, they found that within the 4km (2.5 mile) range of current battery-driven delivery drones, the airborne devices consumed less energy per package and per kilometer than trucks for light deliveries of 0.5kg (1.1lb).
The findings suggest that drones can deliver certain items faster and with less environmental impact than trucks, which form part of a transport sector responsible for around of a fifth of the world’s greenhouse gas emissions.
Stolaroff’s study found that drones require additional warehouse support, due to their limited range, and struggle when it comes to larger packages, especially if the drones are recharged by an electricity grid fed mainly by fossil fuels rather than renewable energy.
Amazon is intent on using drones to transport goods weighing less than 2.5kg, which make up a large majority of its deliveries. In December 2016, the company said it had achieved its first autonomous drone delivery, taking 13 minutes to deliver some popcorn and a TV streaming device to a customer in the UK.