Solar Impulse- Flying Green In The 21st Century
A timeless fable tells of the journey of the tortoise to a party hosted by his friends the birds. It was journey spurred on by imagination, fueled by innovation and enabled by collaboration. The deal was that tortoise would have feathers (graciously donated by his erstwhile feathered friends) glued on with wax, and thus be the odd member of the flock, in the entourage taking on the journey to the far away party possible only by air. In the 21st century airspace, the solar impulse sticks out just like the flying tortoise.
Depending on the moral intended, the fable takes a number of divergent paths albeit with a common tragic end to tortoise’s journey: The sun’s heat, melting of wax and the inevitable. This, tortoise story is a powerful fable appealing to a universal human fantasy: Flight. Notwithstanding that science tells us that some feat it is that the human species is bipedal.
All the same, our imagination through movies, plays and folklore tells a different story. Of airborne superheroes with telling names like Superman. Of superhuman beings with ability over gravity: angels, fairies, Spiderman and witches. More so, in reverence to these fantasies, as we continually consciously chronicle human history, some names shall forever be (the Wright brothers comes to mind). Names that dared like the tortoise.
Now with the feat that is the Solar Impulse, to this list, add modern day innovators like Bertrand Piccard and André Borschberg. 21st century thinkers who have responded to the challenges of the time, and unlike the tortoise flight that was disadvantaged by the sun, have made good of the orb in the sky and make ‘around the world in a solar plane’ possible.
In case you are yet to get the in on the latest show and tell as far as green technology in the aviation industry goes, yet to know of the star attraction at 2011’s edition of the world’s number 1 airshow, the “special guest”as the organizers of the Paris Air show love to put it, we oblige: Solar Impulse HB-SIA, is every reason for all to be excited. Or as Sheryl Crow puts it: The Solar Impulse is the crystallization of soaking up the sun.
The Journey Towards Environmental Friendly Transport Aircraft
Dr Martin Hepperle of the German Aerospace Center, Institute of Aerodynamics and Flow Technology in a 2002 paper presented at the SATB symposium in Munich succinctly elaborates the journey towards environmentally friendly transport aircraft. In the paper, he acknowledges the immediate need for green technology in the aviation industry. A need driven primarily by rising demand for this mode of transport in the 21st century. Dr Hepperle asserts that in order to meet this need, the solution lies in increasing the capacity of air transport while keeping to the demands of the age: sustainability in all activities human this 21st Century.
To realize this , meeting demand for air transport while negating the possibility of global warming, Dr. Hepperle talks of four strategies that the aviation industry has been tinkering with:
- Increasing the number of aircraft,
- Reducing the turn around time at the airport and separation between flights,
- Enlarging the aircraft capacity,
- Increasing the cruise speed of aircraft.
The first two strategies are traditionally rolled out in the aviation industry by simply expanding the fleet range. By whatever name, budget airlines/no frills airlines, this is essentially getting more of the same. Fundamentally, expansion of airport terminals and taxi ways are akin to applying a band aid to a hemorrhaging bullet wound: simply too little benefit at the expense of rising environmental and cost concerns. Better hope lies in the latter two, which as Dr Hepperle scientifically expounds in the paper, calls for a rethink in aircraft design and development of new configurations.
Acknowledging that some strides have been made ( best example being the now operational super jumbo- The A380) Dr Hepperle offers some suggestions on the way forward whilst concluding by highlighting the need of convergence and expansion of ongoing research. Sifting through the equations that Dr Hepperle uses to back the new design suggestions, it is easy to see why the Solar Impulse HB-SIA generates that much excitement.
Solar Impulse HB-SIA Prototype for “The Green 24 Hour Aircraft- 24HAC ” ?
In an April press release, the eagerness of the creators of The Solar Impulse at participating at this year’s Paris Air show is naked. Among the highlighted events to showcase this novel innovation in green energy are the daily flights that visitors to the century old, undoubtedly world’s number 1 airshow will witness weather permitting. As the creators of the Solar Impulse put it:
The statement may appear just as good copy writing, but looking back at Dr Hepperle’s paper, it is apparent that some triumph for electric transportation technology this Solar Impulse is. Key to the configurations for “The Green 24 Hour Aircraft “ lies in noise reduction. Less noise (-10….-20dB) form the engine and airframe both during take off and landing translates to greater 24 hour use.
Reading on the press release, the creators of the Solar Impulse offer:
Electric transportation design enthusiasts must have picked the leading lines in this statement which talk of a generous wing span, light weight and extremely slow speed as key ingredients in configurations of “The Green 24 Hour Aircraft”. As far as light weight goes, thanks to advances in synthetic material engineering , carbon fiber – the super material of the 21st Century- has been a godsend (for lack of a better word).
The role of material engineering in delivering green technology transport solutions for the 21st century is fleshed out in Airbus American rival Boeing . Boeing fronts the delay plagued Dream-liner 787 as it’s answer to the environmentally friendly A380 largely on account of its carbon fiber casing. For Solar Impulse, carbon fiber means that the prototype weighs just as much as an average family car- a paltry 1600kgs.
On account of the extremely slow speed of the Solar Impulse highlighted in the press release, answers are found in Dr Hepperle’s paper which offers the little fact that “noise scales approximately with velocity to the power of 5, it is desirable to fly as slow as possible”.
The ‘real aviation challenge’ that the press release alludes to stems from the fact that as much as slow is desirable, as Dr Hepperle points out, the challenge in configuring “The Green 24 hr aircraft lies in reducing the noise footprint as well by minimizing the time spent close to the ground during take off. To this end, the Solar Impulse wing span that is comparable to that of the A340 is of benefit in take-off aerodynamics as it contributes to lift.
Solar Impulse- Green Technology In and Out
Green technology advancements in the aviation industry have been spurred on by loud noise emanating from global discussions such as the COP 15 and subsequent global warming meets as Cancun. Eminent scholars notably, Jeffery Saachs have led this movement towards a sustainable future. Besides, studies done recently allude that the aviation industry is a major contributor to green house emissions (currently 3% expected to raise to 5% by 2050).
In response corporations like Shell and Virgin Atlantic have been on the forefront in the drive towards use of bio fuels to power commercial flights. In Solar Impulse, a new frontier opens offering hope to humanity in it’s quest to surmount 21st century c challenges.
From airline executives keen on protecting profits by limiting the reliance of the aviation industry oil to farmers in Africa whose horticultural produce faces the risk of boycott by the new age shopper in European markets thanks to labels that scream out a larger carbon footprint thanks to air haul, Solar Impulse is that ray of hope.
Green Technology Firsts’ of The Solar Impulse
- Thanks to 12,000 solar cells integrated to the wing power four electric motors (maximum power 10CV each) and charge 400kg lithium polymer batteries providing enough power to t run the Solar Impulse day and night without the need of fuel
- Almost zero carbon emissions save for probably those inevitably produced during manufacture as with any other product
- 7 years, team of 70 skilled professionals backed by 80 partners to bring us the Solar Impulse
- Largest plane of it’s weight ever built
- Carbon fiber through and through