engineering

Nant de Drance Hydropower Plant

Nant de Drance Hydropower Plant is a engineering 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 Nant de Drance Hydropower Plant rather than just read about it. In short: The Nant de Drance Hydropower Plant is a pumped-storage power station in the canton of Valais in Switzerland. It is within the municipality of Finhaut, district of Saint-Maurice and about 14 km (8.7 mi) southwest of Martigny.

Key takeaways

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

Reference excerpt

The Nant de Drance Hydropower Plant is a pumped-storage power station in the canton of Valais in Switzerland. It is within the municipality of Finhaut, district of Saint-Maurice and about 14 km (8.7 mi) southwest of Martigny. Construction on the power plant began in 2008 and it began operations in 2022. It is owned by Nant de Drance SA, a consortium of Alpiq (39%), SBB (36%), Industrielle Werke Basel (15%) and Forces Motrices Valaisannes (FMV) (10%). The US$1.9 billion plant has an installed capacity of 900 MW and an energy storage capacity of 20 GWh.

Background

On 25 August 2008, the Swiss Federal Department of Environment, Transport, Energy and Communications granted a building permit to Nant de Drance SA for the construction of the plant with a 600 MW design. Preliminary construction began in September 2008 but a concession was granted in April 2011 which allowed for a larger 900 MW plant. Excavation of the tunnels began in 2009 and the caverns commenced in 2010. Raising of the upper Vieux Emosson Dam began in Spring 2013. The underground power house excavation was completed in April 2014. The first generators were tested in 2017. In December 2014, at the International Tunnelling & Underground Space Awards, the project was awarded the Major Tunnelling Project of the Year award in the category of projects over US$500 million.

Design

The power plant uses two existing reservoirs to operate. The lower reservoir, Lac d'Emosson, is formed by the 180 m (590 ft) tall, 555 m (1,821 ft) long Émosson Dam, an arch dam which was completed in 1974. It withholds a reservoir with a storage capacity of 227,000,000 m3 (184,000 acre⋅ft) and surface area of 327 ha (810 acres). The lower reservoir is 4 km (2.5 mi) long and when full, lies 1,930 m (6,330 ft) above sea level. The upper reservoir for the plant, Lac du Vieux Emosson, is formed by a 45 m (148 ft) tall and 170 m (560 ft) long arch dam originally completed in 1955. The dam is 65 m (213 ft) tall. Lac du Vieux Emosson's storage capacity is 25,000,000 m3 (20,000 acre⋅ft) and has a surface area of 55 ha (140 acres). When full, the upper reservoir lies 2,225 m (7,300 ft) above sea level. The power plant is between both reservoirs and uses the pumped-storage hydroelectric method. To accomplish this, when energy demand is high, water is released from the upper reservoir, down a series of 425 m (1,394 ft) penstocks to the six 150 MW reversible Francis turbine-generators in the power plant. The large underground power house measures 194 m (636 ft) long, 52 m (171 ft) high and 32 m (105 ft) wide. After generating power, water from the power plant is discharged to the lower reservoir, releasing up to 20 GWh of energy. When power demand is low, such as at night, the turbines reverse and water can be pumped back up to the upper reservoir for use during high demand periods. As such, it serves as a peaking power plant with 80% efficiency. Under the guidance of AF-Consult Switzerland Ltd as general planner, the civil engineering works were carried out by GMI (a joint venture of Marti and Implenia) and the electro-mechanical works were done by GE Hydro.

References

Illustrations

Worked examples

Example 1 — a first encounter with Nant de Drance Hydropower Plant

Start with the simplest possible case. Write down what Nant de Drance Hydropower Plant claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, 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 Nant de Drance Hydropower Plant 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 Nant de Drance Hydropower Plant 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 Nant de Drance Hydropower Plant

In research: Nant de Drance Hydropower Plant appears in engineering 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 Nant de Drance Hydropower Plant 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: Nant de Drance Hydropower Plant is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arch dams, Buildings and structures in Valais, Dams in Switzerland, so understanding it makes those chapters shorter.
In everyday life: Look for Nant de Drance Hydropower Plant 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 Nant de Drance Hydropower Plant in 20 minutes

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

Frequently asked questions

What is Nant de Drance Hydropower Plant in simple terms?

Why does Nant de Drance Hydropower Plant matter?

Because it connects several engineering 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 Nant de Drance Hydropower Plant?

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 Nant de Drance Hydropower Plant.