The power of the sea: How Britain could harness its greatest natural resource

Hannah Strange and Alex Monro write... In this small grey isle, solar power on a commercial scale was always going to be a non-starter, while onshore wind has stumbled in the face of rural opposition. But now Britain is turning back to the one resource that has for centuries ensured its survival and prosperity. Lashed by some of the roughest seas in the world and with high tidal ranges, Britons could one day see wave and tidal power providing at least one-fifth of its energy needs, with some experts predicting an even greater role.

After years of relative inactivity in the field, Britain is now once again focusing on the power of the ocean wave as a sustainable energy source that could plug the gap left by dwindling North Sea oil and gas stocks. With the world's first commercial tide turbine installed in Northern Ireland earlier this year and a wave farm developed in Edinburgh to take another world first when installed off the coast of Portugal in the autumn, Britain is poised to become the global leader in marine energy. Here we take a look at the best projects under development.

Tidal power

The Severn Barrage

Despite having toyed with the idea since the mid 1900s, plans to harness the tides of the Severn Estuary remain firmly on the drawing board, largely due to environmental and political concerns. In September last year, the Government announced a feasibility study for a 8.6 GW hydro-electric barrier that would generate five percent of Britain's energy needs. The study is due to culminate in a full public consultation in 2010, but opposition by environmental groups and local residents could well hinder progress further.

Strangford Lough

The world's first commercial tide turbine makes use of tidal stream technology, viewed by many experts as preferable to barrages because of the reduced environmental impact and lower costs. Though one Seagen turbine generates just 1.2 MW - enough to power around 1,000 homes, their relatively small size means that several could be deployed at one site, while the depth and slow movement of the blade should leave wildlife unaffected. The company behind the generator, Marine Current Turbines, is to begin work with nPower on larger scale power stations, with sites in Pentland Firth, Anglesey and the Isle of Wight under consideration. Professor Stephen Salter of Edinburgh University says the Pentland Firth site alone could meet up to a quarter of Britain's energy needs, making this narrow strip of water the "Saudi Arabia of tidal energy".

Wave power

Pelamis Wave

Described by the World Energy Council as "the UK's leading device", the Pelamis Wave, developed in Edinburgh, is soon to be installed at Aguçadoura wave farm off the Portuguese coast. Three units, generating a total of 2.25 MW, are to make up the world's first wave power station, while a further 20MW of capacity will be installed in the second phase of the project. Back in its native Britain, Pelamis is set to be deployed at a seven-unit power station off the Cornish coast and at the European Marine Energy Centre in the Orkneys, where four units are to be installed as part of the Orcadian Wave Farm.

Resembling a water-snake bobbing on the surface of the water, the Pelamis is made up of jointed sections which move up and down with the waves, the motion driving electricity generators. Crucially, the units are semi-submerged and can be located far offshore, making them virtually invisible from the shoreline. Currently, the Pelamis Wave is also the most economically viable design in the wave energy field. Click here to see it in action.

The Limpet

The Limpet, developed in 2000 by Wavegen and installed on the Isle of Islay in Scotland, is the world's first commercial wave energy device to be connected to the National Grid. Sitting close by the shoreline, it comprises a hood-shaped shell that contains an oscillating water column. This column is made up of a vertical concrete tube with an opening below the water level. The rise and fall of the sea's water-level is mimicked within the tube, causing the air trapped above to compress and decompress in turn. This pressure makes the air flow backwards and forwards through two turbines, which convert the pneumatic energy into electrical energy. One unit generates up to 500 kW - enough to power more than four hundred homes - with plans underway for a 4MW commercial facility in conjunction with nPower on the Isle of Lewis in Scotland.

C-Wave

The C-Wave was invented in 2002 and the Southampton-based company that invented it plans to connect it to a grid for the first time in 2009. Projects are to be situated around 10-12 miles offshore, virtually eradicating any visual impact. The C-Wave looks like a raft, with two metal "walls" placed at right angles to the water, joined by a submerged steel frame. The walls, which sit parallel to one another but both face the oncoming waves, pivot on axels and move in different directions as a wave reaches them, since they are designed to be a half-wave apart. As the walls pivot from their axels at one end, at the other their movement feeds directly into power generators to create electrical energy.

Comments

[James Russell at How to Turn Your Parents Green]

The Severn Barrage should not have been included here. Whereas the other ideas are examples of innovative technologies that could create export opportunities for British companies, the Severn Barrage is an outmoded and destructive civil engineer's fantasy. No one who considers themselves even faintly Green should touch it with a bargepole, proverbial or otherwise.

[Michael, USA]

Sadly the US and UK share the same mindset on getting things done. We are talking about saving the planet here. NASA uses duct tape for all kind of repairs perhaps use some on those vocal people and then just build what needs building :-)

[Paul Newbold]

It's worth pointing out that there is more than one kind of solar power, for example solar hot water (SHW) and solar photovoltaics (SPV).

SHW is relatively cheap (<5k) and can potentially halve houshold gas/leccy consumption for heating water for most housholds. Solar PV is expensive, and probably only useful for remote 'off grid' houses etc.

The wind/wave generators, which operate regardless of demand, can also be used to generate hydrogen in their off peak hours (which is storable and could fuel nearby hydrogen power stations during peak demand).

[Scott Cunningham]

I have been reading through al this information/comments, above. Each country has it's own viable energy source.
Australia has 30KW of solar radiation/sqM, consant wind either East or West, large tides and large waves.
Just use a combination of these resources depending on the local environment.Oh by the way we have 5 or 6 large wind farms.
they don't kill birds, you have to be aware of them to see them and they have a swoop..............................swoop......................swoop sound so they are not noisy. Put your head in a power plant and tell me what you would prefer.

[g parker]

I can remember in the '50s they said they would have a dam along the Solway Firth. As always in the U.k.all talk and no action.Needless to say it was never built. So just what did happen to that wonderful scheme?

[jerym]

Seems to have thrown that article together rather carelessly. No mention of tidal lagoons.Look it up and appreciate the enormous advantages over barrages and wind power.

[Ross Tennison]

The idea of energy from wave generation is a step in the right direction. But, what bothers me is the fact that we, United States and England, have let these environmentalists rule our lives. Wind farms being denied? Come on, the only pollution we have from those is from the carbon dioxide being emitted by the protesters. The environmentalists need to be erased from any energy equation and then we will truly have energy independence in our countries.
Al Gore, and embarrassment to the USA, is a moron. He also does not practice what he preaches. He is just one example of the problem we have all allowed to happen in our countries. Yes, we do have to take care of our environment, but we also have to have sensible solutions to our needs and not have the huge increase in costs because of these groups.

[Lee]

Solar Power a commercial non starter ?
Ever heard of Germany. It shares the same sunshine hours as the UK, but also has a solar Industry of over 100,000 people. All this with tiny volumes and 10% efficencies. With mass production .... just look at the PC.

Once again the UK sees change as a threat rather than an economic opportunity. Still this negativity would come as no suprise to Tommy Flowers, the guy from the Post Office who designed the worlds first modern computer at Bletchley Park during WW2. After all, he had to pay for it himself and then watch the British government dismantle it all after the war and give it to the Americans. Anyone ever heard of Silicon Valley, IBM, Intel, Microsoft etc etc....

[Frank Upton]

The failure of wind power is not because of rural opposition, but because it doesn't work. It is a feeble and intermittent power source, likely to fail when it is most needed in very cold or very hot weather. Wave power is a better proposition because waves tend to keep going when the wind drops.

[Jane, London]

Cont - that's not to say that it won't be the answer elsewhere in Europe, for example in Spain and Italy from where it can be fed into a European supergrid. In the UK it will always remain for individual use or in the mass market on a very supplementary level. What is the analysis you have done that shows otherwise? Perhaps you should let us know instead of just insulting the writer.

[Jane, London]

John, I think the key words you've missed here are "on a commercial scale". Solar power is not cost-effective even on an individual domestic use - I think you'd struggle to find an expert who believes it will ever be the answer to our energy needs on a commercial scale.

[john matheson]

Solar power a non starter? Have you done the calculations or did you just make that up? Pathetic level of analysis.

[Col]

I seem to remember that way back in 1979 the UK led the world in wave power technology. Then a certain new prime minister took it upon herself to cut funding and switch the money to nuclear power. How so very wrong can you be?

[Martin Bailey]

The C Wave? What's its secret? Simple: it has axels and not traditional axles. That would explain a lot...