astronomy

SolaRoad

SolaRoad 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 SolaRoad rather than just read about it. In short: The SolaRoad was the world's first bike path made from solar panels, and was a prototype project testing the feasibility of various proposals for smart highways. The 72-metre (236 ft) path opened in the week of 21 October 2014, and was designed by a consortium of organizations, which built the pathway in Krommenie, Netherlands.

Key takeaways

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

Reference excerpt

The SolaRoad was the world's first bike path made from solar panels, and was a prototype project testing the feasibility of various proposals for smart highways. The 72-metre (236 ft) path opened in the week of 21 October 2014, and was designed by a consortium of organizations, which built the pathway in Krommenie, Netherlands. The path was formally opened in November 2014 by the Dutch Minister of Energy Henk Kamp. By January 2020, extensive damage was apparent on the path, which had led to the installation of a sign warning of 'Bad Road Surface' (Dutch: Slecht Wegdek). The path was removed in November 2020 and is considered a failure.

Consortium The technology was developed by a consortium consisting of the Netherlands Organisation for Applied Scientific Research (TNO), Imtech (Dynniq) and Ooms Civiel, with a grant of €1.5 million from the province of North Holland as owner of the path. The total cost of the pilot project was €3.5 million. In addition to the €1.5 million from the province of North Holland were that contributions from the TNO, Ooms Civil, Imtech (Dynniq) and the European PV-Sin project (partly subsidized by the Dutch government).

Technology The road surface consisted of prefabricated panels with a surface of 1 centimetre (0.39 in) thick hardened glass. Beneath the glass solar cells were installed. TNO stated that this energy can be used for lighting of the road, traffic lights and road signs. The energy was also delivered to local dwellings. TNO thought that in the future, electrical vehicles might be driven by the road itself. This prototype was studied over the next three years.

Problems and critics On 26 December 2014, a 1-square-metre (11 sq ft) section of the top-layer coating detached from the glass layer, and that portion of the bike path had to be repaired. In October 2015 the top-layer coating was in such poor condition that it was replaced. Critics of the technology see several problems:

The panels might get dirty, because they are lying flat. Mud, snow, etc. might accumulate on the surface. The panels cannot be tilted for highest efficiency, which can be done in a roof installation. Cyclists will block the sunlight when passing. The costs are considered high (3–4 times solar panels on a roof and a conventional pavement layer); about $1,000–$1,400 per square metre ($93–$130/sq ft). This will result in a payback time of over 50 years. With a price of $1,200/m2 ($110/sq ft), a yield of 70 kilowatt-hours per square metre per year (6.5 kWh/sq ft/a) and a lifetime of 20 years, a kWh price of $0.86 can be calculated. Compared to an offshore windfarm the cost are four times higher (average kWh price $0.19). As comparison conventional electricity costs are around $0.05 per kWh. High costs for grid connection, which has to be (over) dimensioned for peak loads only in the summer. Total environmental impact during the lifetime (LCA) is expected to be negative, because of the negative contribution of the reinforced concrete slabs and the epoxy top coating layer in combination with the relatively small amount of produced electricity. SolaRoad could put environmental progress in the slow lane, because of the high costs of this invention.

Results of trial In the first month, the path delivered enough energy to sustain one family. After a six-month test engineers report results are "better than expected". "If we translate this to an annual yield, we expect more than the 70kWh per square metre per year," Sten de Wit, spokesman for SolaRoad, the company that put it in. The EEVblog compared the 6 and 12 months trial results from SolaRoad with data from 3 rooftop solar systems within a few kilometers of the prototype road. The data showed that rooftop solar systems produced twice the output of the SolaRoad per square meter over the same period. In November 2015 it was announced that the path had produced 9800 kWh of electricity in one year. In October 2016, the path was expanded with 7 new improved elements. Two elements of the first generation were removed. In total the expanded path consist of 32 elements (83 meters). In February 2017, a crack appeared in the top coating of one of the improved elements. By January 2020, extensive damage was apparent on the path, which had led to the installation of a sign warning of 'Bad Road Surface' (in Dutch: Slecht Wegdek). The top layer of the experimental bicycle path was removed in November 2020, and replaced by normal asphalt.

Trials with heavy traffic As a follow-up to the bicycle path in Krommenie, two heavy traffic pilots were constructed early March 2019 (100 meter in Spijkenisse and 50 meter in Haarlemermeer). After a week, these pilots were closed to traffic due to problems with the top layer. In July 2019 it was decided to stop the project in Spijkenisse, the Solaroad being beyond repair.

Comparable initiatives Solar Roadways Wattway Smart highway An innovative cycle lane in South Korea has a solar powered roof, providing shelter from sun and rain for cyclists while generating electricity. In this concept the solar panels are directed in the most profitable position for optimal efficiency. The 32 km (20 mile) path between Daejeon and Sejong runs down the middle of a six-lane motorway. Parking under a solar panel roof is an efficient way to produce electricity in combination with infrastructure. Another economically viable solution for harvesting energy from roads is Road Energy Systems (RES). This system is based on solar water heating and could easily be placed in a road without changing its appearance.

References

Illustrations

Worked examples

Example 1 — a first encounter with SolaRoad

Start with the simplest possible case. Write down what SolaRoad 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 SolaRoad 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 SolaRoad 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 SolaRoad

In research: SolaRoad 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 SolaRoad 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: SolaRoad is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2014 establishments, Cycleways in the Netherlands, Photovoltaics, so understanding it makes those chapters shorter.
In everyday life: Look for SolaRoad 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 SolaRoad in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SolaRoad 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 SolaRoad out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SolaRoad in simple terms?

Why does SolaRoad 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 SolaRoad?

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 SolaRoad.