Delivering packages with drones can reduce carbon dioxide emissions in certain circumstances as compared to truck deliveries, a new study from University of Washington transportation engineers finds.
In a paper to be published in an upcoming issue of Transportation Research Part D, researchers found that drones tend to have carbon dioxide emissions advantages over trucks when the drones don't have to fly very far to their destinations or when a delivery route has few recipients.
These heat maps show carbon dioxide emission differences between drone and truck deliveries as a drone's energy requirements (measured in watt-hours per mile) and the number of stops on a route increase. Red areas reflect conditions in which drones emit less carbon dioxide than trucks (lighter packages, fewer stops), while blue areas denote conditions in which drones emit more (heavier packages, more stops).
Credit: University of Washington
Trucks -- which can offer environmental benefits by carrying everything from clothes to appliances to furniture in a single trip -- become a more climate-friendly alternative when a delivery route has many stops or is farther away from a central warehouse.
For small, light packages -- a bottle of medicine or a kid's bathing suit -- drones compete especially well. But the carbon benefits erode as the weight of a package increases, since these unmanned aerial vehicles have to use additional energy to stay aloft with a heavy load.
"Flight is so much more energy-intensive -- getting yourself airborne takes a huge amount of effort. So I initially thought there was no way drones could compete with trucks on carbon dioxide emissions," said senior author Anne Goodchild, a UW associate professor of civil and environmental engineering. "In the end, I was amazed at how energy-efficient drones are in some contexts. Trucks compete better on heavier loads, but for really light packages, drones are awesome."
Interest in the nonmilitary use of drones has increased dramatically with successful operations outside the United States in delivering food, medicine and mail. Within the U.S., the Federal Aviation Administration has recently created legal space for experimenting with drone deliveries, though it is not expected to fully authorize commercial operations for some time.
While public debate has largely focused on cost reduction, privacy implications and airspace congestion, few people have analyzed the environmental consequences that drone technology may have if fully adopted by industries, the researchers found.
The new analysis, led by former UW civil and environmental engineering graduate student Jordan Toy, compares carbon dioxide emissions and vehicle miles traveled from drone and truck deliveries in 10 different, real-world scenarios in Los Angeles. The model incorporated 330 different service zones, with the number of recipients varying from 50 to 500 in each zone.
The researchers relied on models for estimating truck data that were previously used in comparing the environmental footprint of grocery delivery services to personal shopping trips. The analysis also assumed that drones could carry only one package at a time and would return to a depot after each delivery -- requiring far more back-and-forth and vehicle miles traveled than for an equivalent truck route.
The researchers estimated how much energy generation the drone deliveries would require, based on consumption for 10 different hypothetical products. Carbon dioxide emissions were calculated using an average fuel mix for the state of California.
Goodchild said it's unlikely that drones will be used for all delivery applications but that there are some contexts in which they appear to make sense -- such as shorter trips in less densely developed communities, or in controlled places like a military base or campus. One could also envision a hybrid system in which a truck hauls an entire load of packages to a centralized location, and then a fleet of drones fans out in opposite directions to reach individual homes or businesses.
"Given what we found, probably the most realistic scenario is for drones doing the last leg of the delivery," said Goodchild, who also directs the UW Supply Chain Transportation & Logistics Center. "You're probably not going to see these in downtown Seattle anytime soon. But maybe in a rural community with roads that are slow and hard for trucks to navigate and no air space or noise concerns."
Another takeaway for Goodchild was realizing just how much progress engineers can make when they accept a challenge. Making a flying object so light that it can accommodate its own battery and actually perform useful work was an incredibly difficult problem to solve -- yet that technology now exists, Goodchild said.
"We haven't applied the same level of effort to engineering lightweight trucks -- they're excessively heavy and the on-road fleet doesn't look much different than it did a few decades ago," she said. "If we took the same amount of energy we've put into making drones light and efficient, applied that to trucks and got them on the street, we could do so much good for the transportation industry and the environment."
For more information, contact Goodchild at firstname.lastname@example.org.
Jennifer Langston | EurekAlert!
ECG procedure indicates whether an implantable defibrillator will extend a patient's life
02.09.2019 | Technische Universität München
Fracking prompts global spike in atmospheric methane
14.08.2019 | European Geosciences Union
A very special kind of light is emitted by tungsten diselenide layers. The reason for this has been unclear. Now an explanation has been found at TU Wien (Vienna)
It is an exotic phenomenon that nobody was able to explain for years: when energy is supplied to a thin layer of the material tungsten diselenide, it begins to...
Researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich have explored the initial consequences of the interaction of light with molecules on the surface of nanoscopic aerosols.
The nanocosmos is constantly in motion. All natural processes are ultimately determined by the interplay between radiation and matter. Light strikes particles...
Particles that are mere nanometers in size are at the forefront of scientific research today. They come in many different shapes: rods, spheres, cubes, vesicles, S-shaped worms and even donut-like rings. What makes them worthy of scientific study is that, being so tiny, they exhibit quantum mechanical properties not possible with larger objects.
Researchers at the Center for Nanoscale Materials (CNM), a U.S. Department of Energy (DOE) Office of Science User Facility located at DOE's Argonne National...
A new research project at the TH Mittelhessen focusses on the development of a novel light weight design concept for leisure boats and yachts. Professor Stephan Marzi from the THM Institute of Mechanics and Materials collaborates with Krake Catamarane, which is a shipyard located in Apolda, Thuringia.
The project is set up in an international cooperation with Professor Anders Biel from Karlstad University in Sweden and the Swedish company Lamera from...
Superconductivity has fascinated scientists for many years since it offers the potential to revolutionize current technologies. Materials only become superconductors - meaning that electrons can travel in them with no resistance - at very low temperatures. These days, this unique zero resistance superconductivity is commonly found in a number of technologies, such as magnetic resonance imaging (MRI).
Future technologies, however, will harness the total synchrony of electronic behavior in superconductors - a property called the phase. There is currently a...
02.10.2019 | Event News
02.10.2019 | Event News
19.09.2019 | Event News
18.10.2019 | Power and Electrical Engineering
18.10.2019 | Medical Engineering
18.10.2019 | Physics and Astronomy