Posted by Mad Mitch on  UTC 2015-12-07 15:02 Updated on UTC 2016-02-29

Pierre Gosselin has reviewed the current state of play with the Solar Impulse project:

Readers will recall that the Solar Impulse 2 plane was designed by a team of Europeans with the aim of making the first solar-powered “solo flight” around the world and thus show the world the endless possibilities of solar power. Unfortunately the only thing that has been “endless” is the trip itself (and the costs)!

The defects of this project are perfectly clear and were always perfectly clear from the moment the original idea was proposed. Unfortunately, those who are willing to suspend disbelief seem to be oblivious to them. With this project we have moved beyond the suspension of belief required by dead sopranos singing in sacks into fullblown Rumpelstiltskin territory.

Solar Impulse

This level of disbelief can only be suspended by believing that if we only work hard enough and long enough at the development of a technology and, above all, throw enough money at the project all problems will be surmounted.

This proposition is so absurd that for sane humans it really needs no refutation. Nevertheless, for the benefit of those still suspending disbelief in regard to Solar Impulse, let us consider the following sober facts.

Solar energy, the future of aviation

Let's take the popular Airbus A330-200 aircraft as our standard for modern air travel, the result of about a century of aircraft development. This aircraft can carry up to 408 passengers up to 13,450 km at a cruising speed of 871 km/h at a cruising altitude of 11,000 m.

It can do that anywhere in the world, in virtually any weather conditions and by night or by day. It takes off when and where it is supposed to and lands when and where it is supposed to (barring very infrequent special events or problems). In order to transport its maximum load for its maximum range it can carry up to 139,090 litres of aviation fuel. The fuel consumption of modern jets is extensively trimmed and optimised: no airline wants to use a single litre more fuel than it has to. Jet engines suck in air and blow out harmless plant food.

There is no way – absolutely no way, theoretical or practical – that an array of solar panels the size of an aircraft's top surface will ever be able to produce more than a tiny – a miniscule – fraction of the energy the Airbus A330-200 needs to do its job. You cannot do the same job with one-thousandth of that energy. The solar panel system is simply not scaleable. It is true that the early aviation pioneers had engines that would disgrace a modern lawnmower, but the technology at their disposal was scaleable. There was an open end to that technology. It had a future.

Solar Impulse

In the case of Solar Impulse there are limitations that we cannot transcend: the theoretical amount of radiation energy falling on the collectors, the efficiency of the collectors and the size of the array. Solar technology has a very closed end and we have just about reached it. It has no future.

Solar collectors need sunlight to work. At any time, half of the Earth is in darkness. When the Earth is not in darkness there are often clouds – often over large areas and for long periods of time. This is the scientific background to that famous song: The sun has got his hat on, hip-hip-hip-hooray / The sun has got his hat on and he's coming out today.

In addition, quite a bit of energy on a modern aircraft is required for air compression for the humans and electricity generation for the avionics and control systems. Where is this energy supposed to come from?

And so on and so forth.

The really interesting question is not about whether it will work. We have always been able to say with total, eat-my-hat confidence, that the project had no future: it won't work and it never will. This project is as sane as one to promote green-cheese mining on the Moon.

No, the interesting question is how any sponsors in their right minds ever suspended belief sufficiently to put money into this lunacy. And did so long enough – and are still doing so – to continue pouring money into it. But of course: they are Swiss and therefore by definition driven mad by our zombie, Jean-Jacques Rousseau and the idea of green Swiss cleanliness.

Degrees of derangement

Searching for more detailed answers to this question nearly provoked a very unpleasant attack of Wittgenstein's disease. If you are a fellow sufferer you may be well advised not to read any further.

The 'Initiator, Chairman and Pilot' of the Solar Impulse project is Bertrand Piccard. On the Solar Impulse website he tells of his seven principles for motivating people to fight dangerous man-made climate change. The nurse is waiting with his meds (and mine) so let's listen to Piccard's seven principles:

  1. Highlight the solutions instead of the problems … emphasize the tangible benefits of existing clean solutions. [This principle is certainly working well with Solar Impulse: we are speechless with astonishment its benefits.]
  2. Stop threatening human mobility, comfort and economic development in order to protect nature … let’s demonstrate that every one can maintain and even improve their standard of living thanks to affordable and accessible clean technology solutions. [My standard of living is certainly going to improve when I have to wait six months for the next Solar Impulse flight from London to Paris (eight hours for one pilot/passenger with a small toilet bag).]
  3. Speak of profitable investments instead of expensive costs. [The word 'profitable' seems a bit out of place in the Solar Impulse project.]
  4. Offer both rich and poor countries a share in the returns on investment [They will all have to wait an eternity for the revenue stream from Solar Impulse to start to flow. At least that is equal treatment for all.]
  5. Refrain from setting goals without demonstrating how to reach them. [Using Solar Impulse to fly around the world, for example.]
  6. Combine regulations with private initiative … Our society has regulations for education, hygiene, health, justice, etc., but not for preventing the waste of energy and natural resources. This must change! [Yes, we just don't have enough regulations at the moment.]
  7. Act in the interest of today’s generation and not only for future generations. [Solar Impulse really benefits today's generation. Circumnavigation of the globe takes at least two years, depending on the weather.]

By training Piccard is a psychiatrist (no comment) and works at the Swiss Medical Society for Hypnosis (no comment).

Solar Impulse

Piccard (left). They seem to have put the restraints on the wrong way round. Nurse!

Update 29.02.2016

In July 2015 the Solar Impulse team informed its breathless fans via various media outlets that the project needed 20 million Euros to fix the overheating batteries before the aircraft could take off from Hawaii. Piccard the hypnotist had no doubt that he could raise this money.

In November 2015 they told us that they had the money. The plane was still stuck on Hawaii. Helpfully, they reminded us that the circumnavigation of the globe was taking place without using 'a drop of fuel'.

In December, overwhelmed by this success, the plane still in a hangar on Hawaii, André Borschberg wrote: 'Solar Drones: our next Challenge?'

Now that Solar Impulse’s technology has demonstrated that unlimited endurance is possible for an airplane, I am keen to start developing future applications.

Now we learn that, after being stuck on Hawaii for eight months, the plane has been fixed and has made a successful test flight. It reached a height of 2,400 metres and was accompanied by another aircraft. In the irony-free zone that is the Solar Impulse project they once again reminded us that the circumnavigation of the globe was taking place without using 'a drop of fuel' and was intended to encourage the increased use of renewable/clean energy.

The team expects to start out on the rest of the journey on 2 April: 1 April would be just too ironic even for these dreamers.

According to the Solar Impulse website, all this irony can take it out on a pilot:

As for the pilots, they are getting ready to begin flying again. They have been preparing mentally - using hypnosis, meditation, and yoga techniques - and physically with free-fall training and flight simulations.

Just to remind ourselves, this is how far they have got in a year:

Solar Impulse so far

A year of the Solar Impulse plane tearing round the globe, persuading us of the advantages of clean energy.
For the curious: flights: 8/14; total distance: 19,957km; total flight time: 254h 58m; current total duration: 1 year. Way to go!

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