Posts Tagged ‘Solar Impulse 2’

Hot air balloon does in 11 days and 6 hours what Solar Impulse 2 may do in 17 months

July 23, 2016

Solar Impulse 2 set off on its journey around the world on 9th March 2015. Tomorrow it sets off on its last leg from Cairo to Abu Dhabi and it should complete its journey in just under 17 months.

In the meantime, it is reported that Steve Fossett’s record of 13 days and 8 hours to circumnavigate the world in a hot air balloon, set in 2002 has been broken. A Russian balloonist has completed the journey in 11 days and 6 hours. Fedor Konyukhov has been using a Cameron balloon and set off on 12th July.

Flyer: Russian adventurer Fedor Konyukhov has set off on a solo round-the-world flight in a balloon, aiming to beat Steve Fossett’s 14-year-old record for the 33,000 kilometre trip.

Konyukhov set off from Northam, Western Australia yesterday – the same place Steve Fossett set off from in July 2002. The record stands at 13 days 8 hours 33 minutes. Konyukhov is hoping to beat the record by a substantial amount using up-to-date technologies. He is, however, using a very similar balloon – a Roziere 550 built by British company Cameron Balloons.

“Nobody in the world makes better balloons that the Brits,” said Konyukhov, “so our balloon is being made by Cameron Balloons and it will fly on Russian helium.”

balloon australia

Fox News:

An official says a Russian balloonist has claimed a new 11-day round the world record. Support crew member Steve Griffin says Fedor Konyukhov’s balloon on Saturday passed directly over the airfield at the Australian town of Northam where he began his journey on July 12.

American Steve Fossett also started from Northam to set a record of 13 days and eight hours for his 33,000-kilometer (21,000-mile) journey in 2002.

Konyukhov has taken roughly 11 days and six hours. …… Konyukhov is expected to land later Saturday.

Cameron balloon

Structure of the Cameron balloon image via


Remember Solar Impulse 2? Walking around the world would be faster

January 18, 2016

Remember all the hype last year?

The journey around the world started in March 2015 and was supposed to be completed in August 2015.

solar impulse 2 planned track

solar impulse 2 planned track

Leaving from Abu Dhabi they reached Hawaii in mid-July. But their batteries overheated and they are now stuck there till April 2016.  The flight is more hype than substance though there is some clever engineering and pilot endurance involved. It is supposed to be a flight which uses no fuel though reports that the batteries (when working) were recharged at every stop using grid power persist. What is not appreciated is the enormous support entourage that travels with Solar Impulse 2. Tony Thomas has an article about the “stranded monster” in The Spectator, and he points out:

To keep this gossamer confection airborne, an Ilyushin 76 strategic airlifter flies ahead with a blow-up hangar and all the high-tech servicing gear. Aviation buffs call the airlifter a ‘bad-ass’, not just because of its ugly nose and four droopy jets, but because its takeoffs are real Russian screamers. Once aloft, it burns eight tons of CO2-spewing avgas per hour.

This behemoth is accompanied by a   twin-turboprop ATR72 which can carry a support crew of up to 60, apart from the dozens left at Monaco mission control. The ATR burns a more modest tonne of fuel per 90 minutes.

Not quite ‘without using a drop of fuel’. It is “green delusionism” as Tony Thomas names it.

What is also worth noting is

This futuristic plane cruises at about the top speed of a postie’s bike, but can sometimes accelerate away to 90km/h.

Charitably assuming the plane does make it round the world in 18 months, that compares with other round-the-worlders such as:

  •  The Graf Zeppelin in 21 days in 1929.
  • Wiley Post in his Winnie Mae, in nine days in 1933
  • The Rutan Voyager, non-stop non-refuelled in nine days in 1986
  • Bertrand Piccard and Brian Jones by balloon in 20 days in 1999.
  • Solo yachter Francis Joyon, in 58 days in 2008, using that other clean fuel, wind.

Someone could walk the plane’s route (somehow) in two years, not much longer than the flight time.

The flight and the engineering involved for Solar Impulse 2 are not unimpressive. But there is not very much which demonstrates anything which is new about solar energy. The entire enterprise is really about battery technology rather than solar energy. And what it does show is that battery technology has still quite some way to go.

I do dislike the ridiculous hype and the manner in which the “politically correct” and the fame-seekers jump on board.


Solar Impulse voyage abandoned after irreversible battery damage

July 16, 2015

The Solar Impulse 2 “adventure” is over. The lithium-ion batteries have overheated and have been irreversibly damaged. It may fly again in April 2016. Even if it does, that cannot – by any stretch of creative hype – be considered a part of this journey which has effectively been abandoned. By April 2016 a new plane could be built. The planned duration of the whole flight was to have been 5 months. But 4 months after starting in Abu Dhabi the plane has been grounded in Hawaii after completing 17,800 km of its planned 35,000 km journey.

The much hyped journey of Solar Impulse 2 as a solo flight circumnavigating the world was never really about technology or science. It was all about perceptions and PR. The project has been made into a symbol for solar energy  with claims that

Solar Impulse is the only airplane of perpetual endurance, able to fly day and night on solar power, without a drop of fuel. 

This revolutionary single-seater aircraft made of carbon fiber has a 72 meter wingspan (larger than that of the Boeing 747-8I) for a weight of just 2,300 Kg, equivalent to that of a car. The 17,000 solar cells built into the wing supply four electric motors (17.5 CV each) with renewable energy.

During the day, the solar cells recharge lithium batteries weighing 633 Kg (2077 lbs.) which allow the aircraft to fly at night and therefore to have virtually unlimited autonomy.

This flight has done little to demonstrate “perpetual endurance” or “unlimited autonomy”. Every flight starts with fully charged batteries (presumably charged from the grid and that would be fossil energy) and the solar cells need to top up the charge lost during night flying during the day. What has actually been demonstrated with the maximum flight length of five days is that – at best – the stored charge declined by 20% each day. Moreover the batteries suffered irreversible damage after a 5 day flight. That suggests fatal-flaws in the design of the plane, both in the sizing of the solar panels and in the design of the batteries. Firstly, either the power absorbed during flight has been under-estimated or the recharging capacity has. Secondly the immaturity of the battery technology and the inherent risk of over-heating during recharging has popped up again (as with Tesla, Volt and the Dreamliner).

Certainly it has demonstrated the endurance of the pilot flying solo and all credit to him for that. But it has not provided much in the way of new science or demonstration of engineering or technology. That solar cells work and solar energy can be converted into electricity is not new. That battery technology is still struggling to provide efficient, reliable and sustainable charging and recharging has been demonstrated but it did not need a plane to do that. That the cost and weight of extra cells needed to compensate for the lack of solar energy at night is still a major challenge, remains the state of the art.

Following the longest and most difficult leg of the round-the-world journey which lasted 5 days and 5 nights (117 hours and 52 minutes), Solar Impulse will undergo maintenance repairs on the batteriesdue to damages brought about by overheating.

During the first ascent on day one of the flight from Nagoya to Hawaii, the battery temperature increased due to a high climb rate and an over insulation of the gondolas. And while the Mission Team was monitoring this very closely during the flight, there was no way to decrease the temperature for the remaining duration as each daily cycle requires an ascent to 28’000 feet and descent for optimal energy management.

solar impulse route . based on BBC graphic

solar impulse route . based on BBC graphic

Log (BBC):

LEG 1: 9 March. Abu Dhabi (UAE) to Muscat (Oman) – 772km; in 13 hours and 1 minute

LEG 2: 10 March. Muscat (Oman) to Ahmedabad (India) – 1,593km; in 15 hours and 20 minutes

LEG 3: 18 March. Ahmedabad (India) to Varanasi (India) – 1,170km; in 13 hours and 15 minutes

LEG 4: 18 March. Varanasi (India) to Mandalay (Myanmar) – 1,536km; in 13 hours and 29 minutes

LEG 5: 29 March. Mandalay (Myanmar) to Chongqing (China) – 1,450km; in 20 hours and 29 minutes

LEG 6: 21 April. Chongqing (China) to Nanjing (China) – 1,241km; in 17 hours and 22 minutes

LEG 7: 30 May. Nanjing (China) to Nagoya (Japan) – 2,852km; in 44 hours and 9 minutes

Leg 8: 28 June. Nagoya (Japan) to Kalaeloa, Hawaii (USA) – 7,212km; 117 hours and 52 minutes.

The story is now being spun madly to get some PR benefit, but if the objective was to demonstrate unlimited autonomy then it has been a fiasco. Five days and nights is a long way from being unlimited.

Solar Impulse 2 is more fossil than solar

March 18, 2015

The BBC reports that the much hyped, Swiss Solar Impulse 2 is crossing India on its way to Myanmar:

BBCThe solar-powered plane attempting to fly around the world is in the air again, crossing India and hoping to make it to Myanmar on Thursday. Solar Impulse, with Andre Borschberg at the controls, took off from Ahmedabad at 07:18 local time (01:48 GMT).

It is heading to Varanasi in India’s Uttar Pradesh region, where it will make a short “pit stop” before pushing on over the Bay of Bengal. The leg to Mandalay in Myanmar (Burma) will be flown by Bertrand Piccard. The two pilots are taking it in turns to guide Solar Impulse on its circumnavigation of the globe.

So far, they have covered about 2,000km in two segments since beginning the adventure in Abu Dhabi. It will likely be another five months before they return to the United Arab Emirates, having crossed both the Pacific and Atlantic oceans in the process.

It is surely a challenging piloting exercise but it is worth noting, as Pierre Gosselin points out, that some tens of thousands of litres of aviation fuel will be burned to keep Solar Impulse 2 in the air. For safety reasons the batteries on board will probably be fully charged at each take-off. It is not clear as to what extent the batteries will be topped up by using electrical power (which will be predominantly fossil fuel based) at each of the stops.

NoTricksZoneAccording to an audio report by SRF Swiss Radio and Television the Solar Impulse 2 mission involves the substitute pilot, a technical ground crew “of dozens of people” and tonnes of equipment and logistical supplies that have to be flown behind using conventional charter flights. The “fossil fuel-free” Solar Impulse 2 journey is in fact being made possible only with the use of tens of thousands of litres of aviation fuel. This is a fact that is being almost entirely ignored by the media.

The SRF reporter tells listeners:

“It is so that the entire group, the team members, are multiple dozens of men and women, have to fly behind in charter planes. This naturally is the less sustainable aspect of the entire project, but it just isn’t possible any other way. This involves one cargo plane for transporting all the equipment, and a small passenger plane on which the entire group travels to the destinations.”

A promotion video here shows how the aircraft was transported from Europe to its start point in Abu Dhabi earlier this year: With a Boeing 747!

Global map

source Solar Impulse via BBC

Five months, no cargo and no luggage beside the 2 pilots, a large support staff and a great deal of fossil energy somehow seems much less impressive than Jules Verne’s story (published in 1873) envisaging Phileas Fogg and Passepartout circumnavigating the world, with all their luggage and later an Indian princess, in just 80 days.

Green has become the colour of deception.


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