A new study suggests drone deliveries could help reduce carbon emissions by replacing less efficient trucks for lighter weight cargo. Published in the journal Nature Communications, the research adds a new dimension to efforts by companies such as Amazon and Google to expand deliveries by drone.
The researchers, including environmental scientist Joshuah Stolaroff, of the Lawrence Livermore National Laboratory, devoted three years to a comparison of quadcopter drones with diesel-fueled delivery trucks. According to Stolaroff:
“Drones can make a significant impact on emissions, especially now that transport is the biggest polluting sector out there. That last mile of getting goods to a destination is a big part of the emissions picture. There are plenty of plausible scenarios where drones can do environmental good.”
Their research found that in the 4km range of battery powered drones, less energy was consumed per package and per kilometer than by delivery trucks carrying light packages weighing less than 0.5kg. According to the study, drones can deliver items more quickly and with fewer emissions than trucks. Transport emissions account for roughly one fifth of the world’s total, which means these findings could someday lead to a substantial reduction in emissions, if put into practice on a large scale.
Yet some limitations exist which mean drones will be most useful for deliveries in specific scenarios. Drones are less helpful for transporting larger packages, since larger drones for heavier packages are far less energy efficient.
“A drone would be a good option to deliver an iPhone or a pair of sunglasses. A bag of groceries or a computer monitor? Probably not. A larger drone may not be a win for the environment,” according to Stolaroff.
With a shorter range, drones also require more warehouse support than trucks. All of these drawbacks are especially problematic if the drones are charged from a fossil fuel driven electrical grid instead of from a renewable energy source.
Amazon plans to use drones for deliveries weighing less than 2.5kg, which amount to a substantial majority of the company’s deliveries. In 2013, the company managed its first autonomous drone delivery in the UK. Most drone delivery testing has been focused in Europe, where restrictions are more lenient. In the US, drones must be controlled by humans, who must also maintain visual contact with the drone throughout its operation.