Flying cars have been a fantasy of science fiction for decades. It was thought by many that by this point in time we would be zipping around the cities in the air instead of stuck in traffic on the ground. However, here we are in 2019 and I look out the window of my city office and still I don’t see any signs of flying cars in the sky.
Finally, this might be about to change. Companies such as NASA, Boeing and Uber are testing out the latest prototypes to try and bring the first flying cars to our city skies in the next few years.
But apart from looking cool, what potential benefits could flying cars bring for the environment? And will those potential benefits outweigh the disadvantages?
What will flying cars actually be like?
Flying cars have been a dream of many people for a long time. In fact, people have been building flying cars from the start of the century. Henry Ford attempted to do this in 1926 with the ‘Ford Fliver’ which was basically a small plane but intended for the average man. The Fliver’s dream was cut short however when it crashed on a test flight and killed the pilot. This was shortly followed by the Ford ‘Stout Skycar’ in the early 1930s, but due to that being during the great depression and people had more pressing issues than flying cars. Various other people attempted to make a breakthrough over the subsequent decades, but nobody managed to produce anything that got past the prototype stage.
The dream only started to really gain momentum in 2011 when a company called Terrafugia released ‘The Transition’. The Transition was the world’s first roadable aircraft, meaning it could take off and land on a normal road without the need for an airport runway.
At this stage the flying car was fuelled in the same way as most regular cars, with petroleum-based fuel.
The Transition looks and acts like a small plane, but since then, emphasis has since changed and most of the big companies working on the technology today are creating vertical take-off and landing vehicles (VTOLs). And the good news for the environment is that they are mostly electric.
These VTOLs look more like small, light helicopters rather than planes and as technology rapidly advances, companies such as Uber have set the ambitious goal of 2023 for when it’s services will first become commercially available.
For the rest of the article when I talk about flying cars I mean VTOLs. But what are the main potential advantages and disadvantages of this new technology?
Minimizing traffic pollution
One of the biggest problems in most modern cities is traffic caused by road vehicles. Roads that were built a long time ago simply can’t cope with the huge number of cars, trucks and other vehicles that compete for space today.
The majority of these land-based vehicles burn fossil fuels, even when stationary, producing several harmful substances in the process. This includes substances that are directly harmful to the health of humans such as
- carbon monoxide (an odorless, colorless but toxic gas);
- other hydrocarbons such as benzene, which is known to cause cancer;
- sulfur dioxide which causes respiratory problems and;
- tiny solid particles that become suspended in the air (soot)
These compounds are released at all times and so a move to electric vehicles which don’t produce them, whether that is land-based electric vehicles or VTOLs has the potential to have a positive impact.
With traffic being less of a problem it means fuel can be used more efficiently and is not wasted idling in traffic either. As flying cars are phased in, the vehicles that remain on the land will hopefully have to compete with less traffic too.
Lower emissions (over certain distances)
On top of the gases that are directly harmful to human health you have carbon dioxide (CO2) and Nitrous Oxides (N2O) which are greenhouse gases, entering the atmosphere, trapping heat in and causing climate change.
Recently researchers at the University of Michigan ran some tests to see what the reduction in greenhouse gases would be for electric VTOLs.
They found that in certain situations the flying cars reduced emissions quite dramatically. For a trip of 100km a fully charged VTOL with 4 people inside had 52% lower greenhouse gas emissions than the average ground-based gasoline-powered vehicle.
The researchers assume that because the flying cars must be piloted they are more likely to be fully occupied with people sharing lifts, rather than just a single person occupying a car as is currently the case a lot of the time.
They can travel shorter distances to make the same journey
Staying on the theme of lower emissions and greater efficiency. Flying cars can take a much more direct route from point A to point B. This means less fuel is required and the journey times are much quicker as a result when compared to a journey on land. Journeys on land often involve many twists and turns, traffic signals and junctions, all of which reduce the efficiency of the journey and increase fuel consumption.
Frees up the city roads for pedestrians and cyclists
Providing the manufacturers of these electric flying cars can make them effective around our cities in the future, it will free up the roads and the streets for pedestrians and cyclists.
These are the clean and welcome forms of transportation that most people wish for in our cities. But currently, where they are competing for space with cars, it becomes a dangerous and not a very pleasant experience.
With more space created, roads can be turned into large bike lanes or wide pedestrian boulevards, making cities a more pleasant and healthy place to live and work.
Less need for on the ground infrastructure
Today, most cities are still designed and built around cars and other ground-based vehicles. When they expand outwards into the country, more roads are constructed.
But perhaps some of the most damaging roads are those that connect cities. Large motorways and bypasses are built to allow cars to travel from one to another. With increasing numbers of cars, these roads are being widened as well, with more lanes added every year.
These roads often have negative impacts for the environment as they cross fields and pass through woodlands destroying vital habitats for wildlife.
If electric flying cars don’t require this infrastructure on the ground then the need for these destructive constructions is reduced.
Unfortunately, it can’t all be good news. There are several potential disadvantages of flying cars too at this stage of development. It may be a case that this is just because the technology is new and in it’s infancy and these problems will get resolved, but we will have to wait and see.
Emissions over short distances could be higher
Although VTOLs are very efficient once in the air, the take-off and climb phase of the journey requires large amounts of energy. This means that for short trips the benefits in terms of energy use and emissions are much lower.
Researchers at the University of Michigan found that for any trips less than 35km in length, it actually requires less energy to drive a car without any passengers the same distance.
This was an important finding because many people (and companies) see electric flying cars as a solution to transportation within our cities, for journeys like the typical commute which averages around 17km. But this research shows that although VTOLs are promising over longer distances due to their efficiency in cruise phase, these short journeys could actually lead to even higher emissions than existing transportation options.
They can’t carry many passengers compared to other public transport
Due to a requirement that these flying cars must be lightweight to be able to get off the ground without using too much energy, they are only designed for small numbers of people.
One could argue that this is the same for cars, but when you consider we could replace many cars with electric buses or light railways in our cities then the efficiency of electric flying cars once again comes into question.
If VTOLs are to be used in the most effective way, with the most benefits for the environment, they should only be used for longer journeys and investment into other forms of electrified transport should increase at the same time.
This then brings us onto cost. The likelihood is that (at least to begin with), this mode of transportation will be expensive. They will require a trained pilot to transport around a very small amount of people, a bit like getting a mini private jet.
Operators may be able to bring costs down as the technology scales and by utilizing ride sharing to it’s full potential. However, if it does remain expensive this can’t be classed as a truly environmentally beneficial technology. Sustainability has to be affordable to everyone and can’t simply be an expensive luxury for the few.
Take-off and landing infrastructure
We like to imagine flying cars that can just drive along, take off anywhere and land anywhere too. But in reality, this will simply be impractical and dangerous. Therefore, VTOLs are going to need infrastructure to take off and land.
This need for stations will reduce the benefits of this mode of transport along with requiring materials and space which also comes with environmental impacts.
As already mentioned it takes a significant amount of energy to get a flying car airborne, and with a significant amount of energy usually comes a significant amount of noise.
A typical helicopter produces sound at around 100db in flight. So imagine that noise multiplied hundreds of times if flying cars fill our city skies. It’s going to be like living next to a runway all the time!
It again raises the question, will VTOLs be practical in cities? Or will they have to travel from airports, effectively just making them small electric planes?
Although companies such as Uber are aiming for the first commercial flights of electric flying cars within the next few years, there are still a lot of question marks around this technology. Will it actually be useful and not just a novelty, and more importantly, will it have a positive or a negative impact on the environment?
From the recent research carried out, it appears that at this stage they are only worth using for longer trips, perhaps going between towns or cities that are over 50km apart from one another. In this scenario, the efficient cruise phase and high speeds make up for the inefficient take of and landing stages.
I simply can’t see how unless the technology advances significantly, they will every work as a practical transport solution in our cities, but I’d love to be proved wrong of course.
The reality probably is they will have to make up just a small part of future sustainable transport. Alongside electric light railways, trams, self-driving cars etc, which all currently provide much more efficient ways of transporting passengers from A to B.
The other important point to make is that the benefits of electric flying cars, or any other electric vehicle, should only really be factored in when we can guarantee that they are charging their batteries using renewable energy. Yes, they will produce less direct emissions from the tailpipes even when charged from fossil fuel energy, but that is only a small part of the problem. We therefore mustn’t forget to keep pushing towards a renewable grid to power these ‘sustainable’ solutions.
In this article, I have referred to the research carried out at the University of Michigan into the sustainability of VTOLs. I interviewed the lead author of the paper, Akshat Karsliwal, in a podcast episode. So if you want to find out more about this and also hear Akshat’s other thoughts on sustainable cities of the future simply click below to play or find it on any podcast platform.