Delivery drones may have their use-cases — especially for people quarantined at home during coronavirus — but in most cases they’re not any better for the environment than traditional truck delivery.
At least that’s according to a study by Dr. Thomas Kirschstein the Chair of Operations Management at Germany’s Martin-Luther-University Halle-Wittenberg, who focuses on green transportation planning.
While drones require a comparable amount of energy as electric trucks when it comes to drone deliveries in rural settings with long distances between customers, the study found that drone delivery requires more energy than a truck-based parcel delivery system in urban areas where customer density is high and truck tours are comparatively short.
The study compared three types of deliveries:
- Diesel trucks (DVs)
- electric trucks (EVs)
- Drones (UAVs)
From there, the study analyzed factors that go into a vehicle’s environmental footprint including:
- Radius of operation
- weather conditions (energy consumption of drones increases drastically in case of head wind conditions)
- traveling speed
- Number of trips needed to deliver parcels in an area
The study also considered how different companies have various landing and takeoff mechanisms (i.e. fully automatic launching stations, vs. ability to land on ‘rough’ ground vs. drones using some detachment technology like ropes [Flirtey, Alphabet’s Wing (the company formerly known as Google)] or parachutes [Zipline] to drop cargo).
One of the big factors why drones require considerably more relative energy? Hovering.
“Spending even short times hovering generates noticeable energy demands affecting a drone’s radius of operation seriously,” according to the report.
The good news: drones aren’t always worse for the environment. In rural areas, drones can save up to 30% of the total CO2 emissions compared to conventional diesel trucks.
“A UAV delivery system can emit less CO2 than conventional truck-based delivery system when customer density is low (less than 100 stops per truck tour) and the energy demand of UAVs is less than 62 Wh per kilometer,” the study found.
That’s not to say drone deliveries shouldn’t happen. Even the study acknowledged situations where drones may be better, such as speed (drones don’t sit in traffic).
Drones can arrive in a more accurate time delivery window, which might be relevant for something like food delivery (most food delivery services give a half hour window, which can make it tough to plan other components of the meal), or medical delivery (where speed is of utmost importance).
But to claim that drone delivery is always more environmentally friendly than cars might not be as true as some thought it to be.