physics

SeaRaser

SeaRaser is a physics 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 SeaRaser rather than just read about it. In short: The SeaRaser (also called Sea~Ryser) was a wave power concept developed by Alvin Smith from Devon between 1997 and 2019. The device concept uses the power of the waves to pump water uphill into shore mounted tanks, where it can then be released through a conventional hydroelectric turbine.

Key takeaways

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

Reference excerpt

The SeaRaser (also called Sea~Ryser) was a wave power concept developed by Alvin Smith from Devon between 1997 and 2019. The device concept uses the power of the waves to pump water uphill into shore mounted tanks, where it can then be released through a conventional hydroelectric turbine. It consists of two buoys, one on the sea surface the other below fixed to a weight on the sea bed, with a double-acting vertical piston suspended between them. It works in the same manner as a bicycle pump. The device has a self-adjusting mechanism to cope with the rise and fall of the tide. A claimed benefit of the technology was that as water is pumped uphill and stored in tanks, it can then be used when required, and not be at the mercy of the waves. It also does not have any electrical components offshore, and is lubricated purely by seawater, maintenance of the buoy was claimed to be similar to navigation buoys, lifting out of the water for cleaning once a year. Smith also envisaged the device could be used to pump water onshore for desalination and irrigation in dry countries.

History Smith came up with the idea in 1997 when playing with an inflatable ball in a swimming pool, realising the potential as it bobbed to the surface. The device was patented in 2006, in the UK and around the world. Dartmouth Wave Energy Ltd was set up in 2008 to develop the technology, however it was dissolved in December 2019. A prototype was tested in 2008, which pumped water 160 feet (50 m) uphill through a pipe "the diameter of a saucer", however the full-sized device was envisaged to pump water 650 feet (200 m) uphill through a pipe the diameter of a dustbin. The full-size device would be rated at about 0.25 MW. A further prototype was tested in 2009 off the coast of South Devon, and at that time Smith was in talks to build the system in the Middle East, having received "serious interest" from Gulf countries. These tests were conducted in March/April, with the device moored 400 metres (1,300 ft) offshore, and pumped the water up 15 to 20 metres (50 to 70 ft), depending on the height of the tide. In 2011, the Searaser concept was included in an exhibition at the British Library, exploring 15 of the "most ingenious" British inventions of the previous decade. In 2012, it was reported Ecotricity wanted to develop the concept, with founder Dale Vince saying the potential was enormous. It was hoped to test a device offshore at the FabTest site in Falmouth Bay by the end of 2012, however this did not happen. Vince commented in February 2013 that the "Seasraser [sic], [was] undergoing extensive modelling, in preparation for a sea trial". In October 2014, a 1:14 scale model was tested at the University of Plymouth COAST Lab, supported by Ecotricity. A full-scale prototype was then expected to be tested with the following 12 months, with commercial arrays following "within a few years". By 2015, a review of wave energy technologies suggested the concept had reached a technology readiness level of TRL4/5, but there does not appear to be any reported progress since. Smith posted a video in September 2023 demonstrating the concept with a small buoy and a 74 millimetres (2.9 in) diameter pump operating just offshore in small waves at Hayling Island. At age 76, Smith decided to sell the intellectual property, UK patent, and equipment from the model tests.

References

Worked examples

Example 1 — a first encounter with SeaRaser

Start with the simplest possible case. Write down what SeaRaser claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 SeaRaser 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 SeaRaser 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 SeaRaser

In research: SeaRaser appears in physics 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 SeaRaser 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: SeaRaser is common in secondary-school and first-year university syllabi. It links to neighbouring topics Wave energy converters, so understanding it makes those chapters shorter.
In everyday life: Look for SeaRaser 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 SeaRaser in 20 minutes

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

Frequently asked questions

What is SeaRaser in simple terms?

Why does SeaRaser matter?

Because it connects several physics 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 SeaRaser?

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 SeaRaser.