It seems as though it was just yesterday that the idea of electric powered vehicles was a pipe dream, yet today both hybrid electric and fully electric vehicles whiz down ordinary streets in every town. The same may soon be true for hybrid electric airplanes. Airplanes?
Fully electric airplanes are already a reality, though not many people have ever seen one, much less flown in one. In the summer of 2016 a plane called the e-Genius set seven new records as it flew over the Alps. It was built by a team from the University of Stuttgart in Germany and flew non-stop for 300 miles at a speed up to 142 miles per hour. That doesn't sound particularly impressive, until you also find out that it climbed to 20,000 in under two minutes! That's notable for most any plane, but this one was all-electric!
As with automobiles and trucks, battery technology has improved dramatically in the past few minutes, creating the possibility of hybrid and all electric vehicles. However, it's one thing to use electric power to propel an auto or a truck, and something quite different to power an airplane. This is because while the critical limiting factor for batteries in an auto or truck is cost, the limiting factor for an airplane is weight.
The challenge is to improve what's called the energy density of the battery. Energy density is the amount of energy/cubic unit of the battery. An important question to consider is, how many miles can the plane fly per pound of fuel or per pound of battery? Today, it's estimated that 1000 pounds of jet fuel can take an airplane 14 times as far as 1000 pounds of battery. The wings and fuselage must lift and propel the same 1000 pounds, be it fuel or energy, so the critical question is, which one can move the plane farther? Right now, it's a slam dunk for jet fuel.
Batteries, of course, keep improving. Reports of the annual improvement vary, but a commonly stated number is 2 to 3 %. Some quick math says that aircraft won't be able to have viable electric power propulsion systems for another 30 years.
Despite that math, several companies say they'll have commercial hybrid electric aircraft available in just about 5 years. If the energy efficiency math is correct, how is that possible? The answer has to do with an entire "rethink" of the air transportation system. You see, the expected appearance of hybrid electric aircraft in the next decade could change much more than just the propulsion system on the typical aircraft; and it just might usher in the latest example of what Harvard Business School Professor Clayton Christiansen calls "disruptive innovation". Let's consider how this could happen.
The Boeing 737, the workhorse short and mid-range aircraft of the past 40 to 50 years, probably won't have hybrid electric propulsion for another 30 years, maybe longer. However, if some start up aircraft manufacturers have their way, you'll get your first ride on a hybrid plane in the early 2020's. No, it won't be a 140 – 190 seat Boeing 737, or a Boeing 777, Airbus 319, or Airbus 380, it will likely be a 12 passenger seat plane. The manufacturer? A start up called Zunum Aero, located outside of Seattle.
Zunum recently released the following specifications for the plane they hope to begin flight testing as early as 2019:
- 12 passengers (compared with 130 – 200+ passengers for the 737)
- Take off distance of 2,200 feet (6,000 – 7,500 feet for the 737)
- Flight range of 700 miles (3,500 to 3,800 miles for the 737)
- Cruise speed of 340 mph (520 for the 737)
In terms of straight up comparison, we're talking two completely different birds. The Zunum hybrid plane sounds like a toy compared to the workhorse 737, so why would anyone be impressed?
Zunum, and possible "cousins" being built by companies such as Wright Electric, could be highly disruptive because they create the potential for an entirely new aviation market. According to Clayton Christiansen, the Harvard expert, disruptive innovation tends to occur at the bottom end of the market. The products can't compete with the incumbents because they're too small and have too limited a feature set. The main market, and the marketplace leaders, tend to ignore these innovators at the bottom end of the market. Eventually, however, the new entrants at the bottom end of the market become real competition for the main market.
So how could hybrid electric aircraft be disruptive? It's the classic one word answer for disruptive products: cost. Zunum projects that its 12 passenger hybrid will be able to operate at a cost of $ 260/hour. For anyone associated with commercial aviation, that's an astounding number. The commercial sector tends to think in terms of ASM's, an abbreviation for available seat miles. That's the number of seats on the plane times the number of miles the plane will fly, and those in the industry use ASM as a key metric. Zunum projects that its ASM will be eight cents! That's about one tenth the cost of a typical business jet today, meaning that Zunum could reduce the cost of a certain segment of aviation by an order of magnitude.
So just how might a company disrupt commercial aviation with the hybrid electric engine? By creating a practical alternative to the "hub and spoke" system that major airlines use. Most people who fly commercially are familiar with hub and spoke. Imagine that you're like me, a regular customer of United Airlines. I live in the Tampa Bay, Florida area and fly to lots of places. When I get on a United Airlines flight in Tampa, invariably I will fly either to Houston, Washington, Newark, Chicago, Denver, or San Francisco. Most of the time my final destination isn't one of those six cities, but I won't get to my final destination without connecting through one of those hubs.
Pretty much every major airline uses a "hub and spoke" system, so most every airline also flies its passengers through hubs. They're highly efficient, and permit the average passenger to fly to a large number of destinations at comparatively low cost. What's not to like? Plenty! The big problem with "hub and spoke" is that it makes the trip just that much longer, and increases the potential for delays, lost luggage, and every imaginable form of aggravation. Instead of one unpleasant plane ride, you get two or three!
So hybrid electric aircraft, with a dramatically different cost structure, could create lots of new possibilities. One can see right away two great potential benefits:
- Commercial flights from lots of additional airports
- More direct flights rather than connections through a hub, meaning much shorter elapsed time from origin to destination
- The potential to simplify the process of getting on and off a plane
- Much lower cost.
Consider that today, only about 2% of airports have commercial flights. The fact that these new hybrid planes can take off on a 2,200 foot runway means far more airports could have commercial flights. Use of smaller aircraft, with a much lower breakeven cost, means the possibility of far more "point to point" flights.
The idea of replacing "hub and spoke" isn't new. Various entrants to commercial aviation have been trying to do this for years. One very promising entry was DayJet, a Florida based airline startup in the early 2000's. Unfortunately, it hasn't worked. DayJet took off and very soon landed in Chapter 7 bankruptcy liquidation. But DayJet couldn't benefit from the expected economics of some of these new hybrids.
Of course, the new planes are still under development, but here are some possibilities to consider:
- A trip from San Jose, California to Los Angeles presently takes about 4 hours and 40 minutes when flying, and costs about $ 160.
- Zunum expects it can reduce that trip to 2 hours and 15 minutes at a cost of $ 120, a third less. It isn't that Zunum's plane will be flying faster (it won't), it's that smaller airports can be utilized.
Rather than fly through big airports like LAX in Los Angeles, why not go out to a small local airport, park your car, then just get on the plane, maybe even without going through TSA? Sign me up! That's always been the great appeal of private aviation, just that you had to have at least $ 20 million in your bank account to participate. Smaller, slower planes such as the one Zunum is promising could provide the tortoise to commercial aviation's hare, to borrow from Aesop, and make this available to everyone else.
Hybrid aviation should often one other important benefit not yet mentioned. In fact, this other benefit has been the real driver of the industry: lower carbon emissions. Aviation is a major contributor to greenhouse gases worldwide, and it's expected to get much worse over the next 30 years with continued aviation expansion. Hybrid technology, then all electric, could have a major impact on aviation-caused greenhouse gas emissions.
Please remember, these aircraft are still under development so don't plan on booking a ticket any time soon, unless you happen to be a test pilot. But they could have a dramatic impact on aviation, not simply because they should produce significant reductions in carbon emissions, but mainly, and unexpectedly, because their dramatically different economics could really change flying. They could, in the parlance of Clayton Christiansen, be "disruptive innovators". Not quite, but soon, ready for take off.
