While cars have become greener, wind farms windier and smartphones smaller, it has been a common gripe at the aviation industry that planes and air trapped full technology hasn’t significantly improved since the 1960s. On the surface this criticism is fair enough, at least to those pundits who are unfamiliar with the industry.
The Queen of the Skies, the mighty Boeing 747, for instance, which is still the workhorse of transatlantic business travellers, has seen service essentially unchanged since 1969. Even short haul flights on humbler aircraft drink thousands of gallons of precious and irreplaceable aircraft fuel, all expensively distilled from fossil fuels. No wonder that the aviation industry has faced mounting criticism from environmental campaigners on one hand, and increased taxes and regulation from governments on the other; the costs of course, being directly or indirectly passed onto business customers.
It is against this background that EasyJet’s new hybrid aircraft is such a breath of fresh air. Although still in the planning stage, the new aircraft has caused quite a stir among industry observers. When in the air, the hybrid technology could save the airline more than 50,000 tonnes of fuel per year, not to mention a drastic reduction in dreaded CO2 emissions.
So how does it work?
The most fuel hungry elements of an aircraft’s journey are the take-off, which requires enormous power and the taxiing stage both before and after take-off. This is because no matter how aerodynamic and efficient an aircraft is, when in flight it is an enormous, clumsy and difficult machine to move around on its own power when on the ground. On the other hand, the part of the journey that requires the least fuel is landing, which is ironic as this is the part of the journey which generates the most kinetic energy.
The engineers designing the new hybrid engine seek to harvest energy generated by the landing and use it to charge a hydrogen battery that can be used to cut fuel consumption during taxiing. While landing the aircraft’s battery is progressively charged, with the energy being transferred to a green taxiing engine located to the rear of the plane. Once safely on the ground, the engines can be cut and the stored energy used to power the plane.
How much will this save?
Considering average flights involve 20 minutes or more of taxiing around runways, EasyJet engineers estimate savings of approximately 4% in fuel consumption and 7% of CO2 emissions per journey. The only additional waste product will be water generated by the hydrogen cell container, which would need to be replaced between flights.
So the million-dollar question remains; will savings to the airlines from hybrid engines result in a cut in business travel costs? A cynic might say no, but in a market where airlines are keen to become more competitive in the face of reduced corporate travel budgets, we may have reason to be hopeful. Certainly if the automotive industry is any comparison, green technologies have made cars both more affordable and efficient. We can expect a similar impact in the world of business air travel.