astronomy

Tour de Sol

Tour de Sol is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Tour de Sol rather than just read about it. In short: The Tour de Sol in Switzerland was the first rally for solar powered vehicles. It was carried out annually from 1985 to 1993.

Key takeaways

Tour de Sol belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Tour de Sol to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tour de Sol from memory before moving on to harder problems.

Reference excerpt

The Tour de Sol in Switzerland was the first rally for solar powered vehicles. It was carried out annually from 1985 to 1993. The first event started on June 25 in Romanshorn on the Lake of Constance, and finished on June 30 in Geneva. 72 vehicles started in two classes; over 50 finished. The vehicles were powered exclusively by direct onboard solar power in addition to an initial charge of the onboard accumulators. The second class also allowed direct human power with pedals. The rally was conceived as a kind of race with the winners being those using the least time to travel the set course each day. The course was on unclosed public roads and the drivers were required to adhere all traffic rules and speed limits. The first events were very popular with thousands of spectators lining the roads and visiting the camps where the vehicles stopped each day. In later years the fastest vehicles also raced on round-circuit closed-off courses each day after arriving at the stops. From 1990 the organisers also held separate events called Tour de Sol Alpine. These included closed courses on frozen lakes and snowy roads and on unclosed mountain passes. After a few years other organisers carried out similar rallies, e.g. the American Tour de Sol. In 1988 the Tour de Sol also held the first race for solar powered boats on July 1 at Estavayer-le-Lac. The Tour de Sol initially stipulated direct solar power from onboard solar cells. After the first couple of events, a class was introduced which allowed charging accumulators from stationary solar panels and swapping accumulators. Later another class also allowed charging from the 230 VAC mains, provided that this amount of electricity was generated elsewhere by solar power and fed into the mains. This led to the development of the first domestic grid-feed systems. The legal form of the Tour de Sol was a foundation. It ceased in 2002. Solar engineer Josef Jenni is credited as the inventor of the event and Urs Muntwyler developed and led it for most of its years.

Courses The course of the first Tour de Sol was relatively flat and direct, in later years the courses were circuitous and included mountain passes.

1985: Romanshorn - Geneva 1986: Freiburg (Germany) - Suhr 1987: Biel - Arosa 1988: Zürich - Etoy 1989: Rheinfelden - Locarno 1990: Schaffhausen - Münsingen 1990: Tour de Sol Alpine (on snow): Lenzerheide-Valbella (dito in 1991) 1991: Suhr - Beatenberg (total altitude gain 5000 m) 1991: Tour de Sol Alpine (on roads): Laax - St. Moritz 1992: Pforzheim (Germany) - Saas Fee 1993: Luzern - Adelboden

Regulations The detailed regulations for the vehicles were described in a 24-page handbook. The main specifications for the vehicles were for the size of the solar cells and the accumulator battery. The racing category allowed a panel up to 6 m2 or 480 Watts peak and a battery capacity of up to 4.8 kWh. These vehicles were checked by the police and got temporary licences for the duration of the event. For vehicles with a regular road licence other specifications applied.

Two-wheelers The vehicles mostly had three or four wheels but from the beginning a few bicycles with solar trailers participated. This later led to the development of Swiss production electric bicycles and motorcycles, notably the first production pedelec, the Velocity, and soon after the Flyer, which was heavily promoted and increased the popularity of pedelecs in Switzerland by a great deal.

Illustrations

Worked examples

Example 1 — a first encounter with Tour de Sol

Start with the simplest possible case. Write down what Tour de Sol claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Tour de Sol before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Tour de Sol ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Tour de Sol

In research: Tour de Sol appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Tour de Sol in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Tour de Sol is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1985 establishments in Switzerland, Electric vehicles in Switzerland, Photovoltaics, so understanding it makes those chapters shorter.
In everyday life: Look for Tour de Sol outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Tour de Sol in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tour de Sol means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Tour de Sol out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tour de Sol in simple terms?

The Tour de Sol in Switzerland was the first rally for solar powered vehicles. It was carried out annually from 1985 to 1993.

Why does Tour de Sol matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Tour de Sol?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Tour de Sol.