Before starting to build something, it is essential to analyze the positives and negatives first. In this case, this is being examined for conducting electrical airplanes and the efforts to build these electric airplanes. There are many benefits and drawbacks of how and why this product is needed from energy storage density, the rate of energy consumption, and heat expenditure.
A big part of this creation is the amount of power needed to start, take off and land airplanes. In other words, the amount of watt-hours per mile needed. Depending on the type of plane, the amount of watt-hours per kilogram will vary. For example, jet fuel has a specific energy of 12,000 watt-hours per kilogram. Since there are so many different plane sizes, the statistics for the amount of watt-hours per kilogram will be different, so it is evident to pick a starting point. Something like flying cars or in this case, electric planes can take years and years to actually start running and most importantly, to work. I believe with the technology and knowledge that we have today, one day we can say electrical planes are officially in tact and ready for passengers to hop on board.
As stated in the beginning, the process of building electrical planes is going to come with challenges. One major issue when it comes to battery-powered planes is density. The best lithium-ion batteries available today put out 250 watt-hours per kilogram. A lithium-ion battery or Li-ion battery is a type of rechargeable battery. Lithium-ion batteries are commonly used for portable electronics and electric vehicles, and are growing in popularity for military and aerospace applications. These batteries are identified to be sufficient enough to power cars. However, the weight can become an issue when the product is in the air. In comparison, Jet fuel has an energy-density of 11,890 watt-hours per kilogram. Even though batteries may never reach this level of energy storage, I found the estimated amount that a level of 800 watt-hours per kilogram will be a turning point based on my calculations. This energy-weight balance would allow a 737-sized plane complete up to a 600 mile journey (which represents about half of all global flights). 250 watt-hours per kilogram have already proved viable in cars. Battery densities have been increasing 3-4 percent per year recently and if this continues we could hit the 800 watt-hour mark by around the middle of the century.
\[ 3.2 \text{ watt-hours per kilogram} \times \ 250 \text{ watt-hours per kilogram} = 800 \text{ watt-hours per kilogram}\]
In the beginning of my research, I read how important it is for engineers to have the right numbers of every specific thing about the plane in order to build it with its appropriate fit. For example, if a size 737 plane is needed to complete a 600 mile journey, they need to know exactly how many watt-hours per kilogram is needed. These end results show one of the most important aspects regarding watts-hours per kilogram, that will allow engineers to apply the weight of the plane, how long of a journey it can take, and the amount of battery density is needed. The switch to electric airplanes is an important step for environmental conservation, technology, and marketability of electric aviation. In terms of the current output of emissions within the realm of aviation, travel by air accounts for 2 percent of the world’s total carbon dioxide emissions. Airplanes also put out other potent pollutants at cruising altitudes such as nitrogen oxides, which have a strong warming effect. In other words, this is seen as a negative aspect for our environment, especially our atmosphere.
Energy can be stored in a given amount of weight of the on-board energy source. The best batteries store about 40 times less energy per unit of weight than jet fuel, a greater share of their energy is available to drive motion. Ultimately, for a given weight, jet fuel contains about 14 times more usable energy than a state-of-the-art lithium-ion battery. This makes batteries relatively heavy for aviation. This is starting to worry airline companies about weight-imposing fees on luggage in part to limit how much planes have to carry, etc. Keep in mind, there are many little things to keep in mind such as weight of luggage, additional food and drink weight, etc.
The Global Aviation Battery Market is important for those looking to build electrical planes. Since the demand for air transportation has significantly increased, the rising purposing power people across the world is expected to increase the demand for aircraft. Now this doesn’t necessarily pertain directly to electrical planes. However, this concept has now taken off to increase the emergence of electrical aircrafts. In fact, major developments on this technology have recently taken off. Several companies are currently working on prototypes of electric aircraft and hybrid aircraft. Also, several companies have been developing technologies to deploy battery-electric aircraft. Above states important statistical facts about the increasing emergence of electric aircrafts to boost growth between 2019 and 2023. The industry of global aviation is crucial as it includes air transport service providers of passenger and cargo. Industry services are used by individuals and business,—international, domestic, and regional— and governments around the world. Those involved in the industry need to stay up to date with this stuff, because if everything goes electrical within the next couple of decades, the aircraft industry will become a completely different place.
Previously mentioned, a big difference is represented in a small aircraft as opposed to big aircraft. Whether dealing with energy density of fuel, watts-hours per kilogram, etc, it would take a significantly more powerful battery to compete with a transcontinental airliner. It is said that the shorter routes are still a much more promising target than the longer routes. Not only is battery performance steadily improving, but there are ways to improve the performance of electric motors and thereby squeeze more range out of existing battery technology. Timothy Lee discusses how, “a Seattle startup called Zunum Aero is developing an electric airplane that combines battery power with a conventional generator. Zunum expects its first airplane, which its aiming to release in the early 2020s, will have a range of 700 miles—far enough to serve many popular short-haul routes in the United States and around the world”.
Another factor for electric airplanes to be invented, are how Aircraft designers need to closely examine the power and/or how quickly the stored energy is available. This is important because ramping up to take off in a jet plane or pushing down against gravity in a helicopter takes much more power than turning the wheels of a car or truck.
Therefore, e-VTOL batteries must be able to discharge at rates roughly 10 times faster than the batteries in electric road vehicles. When batteries discharge more quickly, they get a lot hotter. Compare it to when your laptop fan spins at full speed when trying to stream a TV show as your playing a game and downloading a large file all at the same time. To compare, a vehicle battery pack needs to be cooled down even faster whenever it is asked to produce more power. To have a better grasp on what e-VOTL batteries are, they are battery packs to use in electric vertical-takeoff-and-landing (eVOTL) vehicles, companies need data. That is a key characteristic of any battery that is going to be flying this aircraft.
Road vehicles’ batteries don’t heat up nearly as much while driving, so they can be cooled by the air passing by or with simple coolants. An e-VTOL taxi, however, would generate an enormous amount of heat on takeoff that would take a long time to cool — and on short trips might not even fully cool down before heating up again on landing. Relative to the battery pack size, for the same distance traveled, the amount of heat generated by an e-VTOL battery during takeoff and landing is far more than electric cars and semi-trucks.
I think one of the most important questions to ask is, “do electric planes exist at all?” In fact, yes they do! There is a solar powered plane out there called Solar Impulse 2 (glider) that flew 26,000 miles all around the world. This aircraft is powered by photovoltaic cells and is capable of taking off under its own power. A photovoltaic cell is otherwise known as a solar cell, which is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. The idea is that it does exist, and it is possible. More than 17’000 solar cells, collecting up to 340kWh of solar energy per day and representing 269.5 m2. The energy collected by the solar cells is stored in lithium polymer batteries, and after my calculations, I found that the energy density is optimized to 260 Wh / kg afterwards.
Overall, there are many benefits and drawbacks of how and why this product is needed, and the complications that come in the way will one day not be complicated anymore. I think it is important that we are trying to move onto the more electric side of things for several reasons. It is more efficient, prices are generally more stable, and it costs less than half as much to travel the same distance in an electrical vehicle as opposed to a conventional vehicle.
This graphic describes how as each year goes on, the development of electric aircraft is accelerating. This more than likely means that the probability that these products will not just be a thing, but also become very popular high.
Some examples of electrical aircrafts. Click here to view more, and read more about them.
- By Joby Aviation
This company spent the last decade developing their own electric motors and their current VTOL design from the ground up. The company recently secured $100 million in Series B financing to prepare for production and certification. The new vehicle is being developed to fly as many as five people as far as 150 miles on a single electric charge.
2. By Eviation Alice
https://arstechnica.com/cars/2017/10/airline-plans-to-use-electric-airplanes-in-10-years-is -that-possible/
Around the world to promote clean technologies. (n.d.). Retrieved from https://aroundtheworld.solarimpulse.com/adventure
Gaj, E. (2018, July 8). The electric aircraft is taking off. Retrieved from https://techcrunch.com/2018/07/08/the-electric-aircraft-is-taking-off/ .
Irfan, U. (2019, April 9). Forget cars. We need electric airplanes. Retrieved from https://www.vox.com/2019/3/1/18241489/electric-batteries-aircraft-climate-change
Taylor, Alan. “Flying Around the World in a Solar Powered Plane.” The Atlantic, Atlantic Media Company, 26 July 2016,
www.theatlantic.com/photo/2016/07/flying-around-the-world-in-a-solar-powered-plane/4 93085/.
Why Aren’t There Electric Airplanes Yet? It Comes Down to Batteries. (2018, November 28). Retrieved from
https://www.smithsonianmag.com/innovation/why-arent-there-electric-airplanes-yet-it-co mes-down-batteries-180970909/