The effectiveness of courier drones will depend on where you live.

If the idea of ​​how swarms of delivery drones delivering parcels to our cities began as a comic, then for the time being the end of this anecdote is not visible. In 2015, Amazon filed a patent for a command center patent for drones, something like a beehive stuck in the city center — a metaphor that never causes concern. Google has its own program in development, which today includes burrito delivery. Again, if this is a joke, they tell it for a very long time.

Forget for a second about the insane logistics of such a system, or even whether you will like it if your city is filled with drones. The main question is: will this method really be better and more efficient than standard trucks? And without such a system in reality, it is difficult to answer it.

But today, in Nature Communications magazine, a group of researchers tried to simulate the energy efficiency of delivery by drones and compare it with classic fleet of courier trucks. What will be better? It turns out that everything depends on a heap of factors that you, most likely, could not even imagine. But it is their companies and regulators who will have to consider when automatic delivery becomes more likely.

First, renewable energy infrastructure is different in different parts of the country, such as solar, which means that charging all of these drones will result in emissions of varying amounts of carbon dioxide, depending on the terrain. In this study, researchers compared emissions from both ends of the spectrum: in the very "green" state of California and in the opposite, Missouri.
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“We got mixed results,” says lead author John Stolyarov, an environmentalist at the Livermore National Laboratory . “There is a possibility that drones will reduce greenhouse gas emissions and energy use, but they need to be very carefully deployed.”

A small drone operating in a warehouse in California will be responsible for emitting around 430 grams of CO ₂ per package, compared with 915 grams for which the truck is responsible. But in a not so green Missouri, a small drone will be responsible for 850 grams of CO ₂ per package, and a truck for 1100 grams. Therefore, in California there will be 53% savings on emissions, and in Missouri - 23%.

But the location is not the only parameter that affects emissions, it is also necessary to consider the size. Scientists modeled two different drons, a small quadcopter capable of carrying half a kilo, and a large octocopter capable of carrying 8 kilograms each. They checked them in the real world, at different speeds and with different winds, after which they entered these data into their models.

"At the other end of the spectrum, it turns out that a large drone is 9% more efficient than a diesel truck in California, and 50% worse than a truck in Missouri."

But the model must make certain assumptions that do not necessarily coincide with how the delivery by drones will be implemented in reality. For example, drones in simulations fly directly, like birds. “In the real world, depending on the rules and laws, special routes may appear that should be followed by drones,” Stolyarov said. “This will lengthen the path, the drones will have to fly further, or they will have to build more warehouses to serve the same territory.”

This difference is important because, taking into account modern batteries, one drone carrying one parcel to one address can fly no more than three kilometers. The researchers suggested that the warehouses - where the drones will load and charge - will be built taking into account this short range. In a relatively small San Francisco, four warehouses will be needed, and in a fairly large area of ​​the Gulf - more than 100.

But the more warehouses you build, the more energy you use to power, heat and air them, which affects the energy benefits of delivery. The researchers did not lay down the difference in energy, depending on whether the trucks deliver goods from several warehouses or from one warehouse. One way to solve the problem is to convert existing power into hives for drones. Amazon, which now owns Whole Foods , could get drones from rooftops already scattered around cities like San Francisco.

And yet it is hard to imagine the urban version of such a delivery, which will not quickly fall into chaos. Indeed, hundreds of parcels are getting into the express truck. “Every time you see such a van, you can imagine a hundred drones in the sky,” says co-author, Costa Samaras, a civilian engineer at Carnegie Mellon. “Here you have the noise, the visual component, the security, and the privacy.”

And this is not to mention how different networks of drones can not interfere with each other. Amazon can have its own park, Google has its own, and the grocery network has its own. It’s easy to organize your own swarm of drones, but try sharing the same sky with the squadrons of others.

Drones couriers, like any automation, can ultimately do a good service to companies, but this problem can be solved correctly and incorrectly. “It's pretty obvious that companies are interested,” Samaras says. “It is important to understand how regulators will be able to manage the development of this topic for mutual benefit, before the sky is filled with flocks of drones delivering packages.”

Data

• While some companies are considering the possibility of airborne delivery of goods by drones, others want to use ground robots. In San Francisco, Marble startup rides through one of the most challenging areas of the city.
• Another ground robot courier [approx. transl.]
• Recently, for security reasons, the San Francisco City Supervisory Authority has seriously limited the use of robots couriers on the city’s sidewalks.
• In the meantime, one startup in Rwanda is doing a slightly more honorable thing: delivering blood by drones .
• Moscow authorities have begun testing a new method of delivering goods using courier drones. So far, drones are using up to three kilograms or light correspondence for delivering small loads, but in the future the developers are planning to improve the capabilities of “flying couriers”. [approx. transl.]