If Portugal can rule the waves, why not Scotland?

The "serpents" are the creation of Edinburgh-based Pelamis Wave Power, a company named after Pelamis platurus, a sea snake.

However, despite being thought up in Edinburgh, the three devices have been installed off Portugal.

Unlike the turbines used in an offshore wind farm, the wave-power devices are long tubular structures that float on the surface of the ocean.

They are positioned to face the waves head on, and contain generators that convert the energy to power, which can then be fed into an underwater grid.

A second phase of the 7 million project is already planned, which would bring another 25 devices, taking the installed capacity up to 21 megawatts.

Once complete, it could meet the electricity demand of 15,000 households, while displacing more than 60,000 tonnes of damaging carbon dioxide per year.

Alex Salmond, the First Minister, has an ambition to turn Scotland into the green energy capital of Europe, and a world leader in marine technology, but those behind the scheme say it was the Portuguese government that provided the perfect environment for attracting investment.

In contrast, critics say the Scottish Government still must overcome the challenges of an inadequate grid network, high charges for transmitting electricity from isolated locations, and a planning system that can put the brakes on projects for many years.

Anthony Kennaway, from Babcock & Brown, an asset management company with a 46 per cent share in the project, said: "It's absolutely a landmark in the development of a new renewable energy tech- nology. It's the first of its kind worldwide and Portugal has created the conditions to make it possible. It's a huge step forward in harnessing the fantastic power of the sea."

It was so attractive to invest in a project in Portugal because they created a "feed-in tariff", where a higher-than-market rate is paid for the electricity produced, he said. "If you get a guaranteed feed-in tariff, for an investor like Babcock & Brown that means you are much more able to see a long-term business in it."

He thinks it is much more attractive for investors than the system of subsidies under the Renewables Obligation that has been adopted in the UK.

And he thinks Portugal is "head and shoulders above the rest of Europe and probably the rest of the world" when it comes to the renewable industry. It already produces 40 per cent of its electricity from renewable sources.

However, Jason Ormiston, the chief executive of Scottish Renewables, says there is still every opportunity for Scotland to lead the field.

He believes the financial support, in the form of subsidies within the Renewables Obligation, are now "similar if not better than what the Portuguese are offering".

He added: "To suggest that Portugal is miles ahead is wrong. It's ahead because it provided the early signal and that's why Pelamis went there first. There's now interest in putting similar devices in Scottish waters."

He thinks the launch of the wave farm is a "major, major milestone" for the sector, for Scotland as well as Portugal, with similar schemes likely to be built in the Northern or Western Isles, or off the West Coast, by the end of the decade.

Despite Portugal's waters providing a home to the first commercial wave farm, a Limpet wave device invented by Wavegen was installed at Islay, off Scotland's west coast, as long ago as 2000.

And Scotland is home to the world- leading European Marine Energy Centre (Emec) off Orkney, where prototype wave and tidal devices are being developed and tested, and where Pelamis has consent to build four of its wave machines.

It has been estimated Scotland has potential to generate 60 gigawatts of renewable electricity, and some of the best conditions for marine renewables in Europe. Mr Ormiston thinks marine technology could bring billions of pounds of investment to Scotland, and enable the provision of many gigawatts of green electricity for the UK and the rest of Europe.

However, he says there are key issues in Scotland that need to be resolved before similar wave farms will spring up off our coast, particularly difficulty accessing the electricity grid, the lengthy planning process and the high charges for transmitting electricity from remote locations.

Other barriers to offshore wave farms are likely to include concerns about damage to the marine environment, opposition from the fishing industry, and concern from the shipping sector.

And constructing the wave farms in the harsh environments out to sea, as well as maintaining them once they are built, poses technical challenges.

Max Carcas, business development director at Pelamis, agrees that it is the timing of the Portuguese move to bring in feed-in tariffs that made it so attractive for the scheme to be built there. However, he is supportive of the Scottish Government's announcement last week that it plans to vary subsidies given out through the Renewables Obligation scheme depending on renewable type, and giving tidal five times as much as wind, and wave three times as much.

Mr Carcas says: "I expect there will be projects coming on-stream in Scotland in the near future."

Liam McArthur, the Lib Dem energy spokesman, says it would have been great for the wave farm to have been off the Scottish coast, but he adds that Scotland is still "world leading".

The MSP says: "If you were to look at where we are with marine technology and draw a parallel with aviation, we are where the Wright Brothers were. We have proved it can work, but we are not yet sure how best it can work."

However, he thinks there must be a commitment from the Scottish Government to continue the wave and tidal energy scheme of grants for such new projects. He adds: "They talk very much about the Saltire Prize (for developments in marine energy], which is a one-off big-bang and we still don't have the eligibility criteria around that."

A spokesman for the Scottish Government describes Pelamis as a "Scottish success story". He adds: "Scotland has four consented Pelamis machines at the world-renowned European Marine Energy Centre in Orkney, the biggest wave-energy project in the world, and we are dealing now with an application for consent for ten Wavegen turbines in waters off Lewis, with further applications expected.

"The Scottish Government is offering the highest support in the UK for wave and tidal power plus an unrivalled sea resource drawing developers to Scottish waters."

He adds that the 10 million Saltire Prize will set a challenge for scientists to push forward new frontiers.

One machine can meet demand for 500 homes

THE Pelamis devices convert the energy that is stored in waves and that originally came from the wind into electricity.

As well as looking like gigantic snakes, they have been likened to semi-submerged trains.

Each has four "carriages", which are joined together so they oscillate over the water.

The machines move up and down and side to side as the waves hit, and it is that movement which enables them to generate electricity.

Officially known as Pelamis Wave Energy Converters, the motion of the devices is resisted by hydraulic rams, which pump high-pressure fluid through hydraulic motors.

These drive electrical generators to produce electricity. Power is fed down a single umbilical cable to a junction on the sea bed.

Several of the 750-kilowatt devices can be connected together and linked to shore through a single seabed cable.

The energy produced by the devices depends on the conditions of the site in the ocean where they are installed, but on average they will produce between 25 and 40 per cent output over the course of a year.

This compares to an average output from wind turbines of about 30 per cent.

Each wave machine can provide sufficient power to meet the annual electricity demand of about 500 homes.

According to the British Wind Energy Association, wave power could displace between one and two billion tonnes of each year from conventional fossil fuel-generating sources, such as coal-fired power stations. Wave energy is essentially stored, concentrated wind energy.

The waves are created by the transfer of energy from the wind as it blows over the surface of the water.

It is also beneficial in that it provides a secure supply of electricity, as it is both indigenous and depends on a resource – wind – that will not run out.

However, wave power is not as predictable as tidal power.

The tides can be forecast, whereas the waves depend on wind, which is difficult to predict.