Its source is a place called Hayle, a sleepy little enclave just a few minutes' drive from the restaurants and amusement arcades of the resort of St Ives.
This is the headquarters of the south-west's ambitions for marine energy, centred around Wave Hub, a site for testing wave-powered turbines. It is styling itself as the most advanced stop in the long road towards developing devices that will finally realise all the years of promises about the potential for getting electricity from sea water.
According to the Wave Hub pitch, once you have done your research and development and then developed a commercially viable device with testing in the world-leading Orkneys, you should then come to Cornwall to test an array of devices. This is widely seen as the final step that would give big utilities the confidence to commission wave farms on a full commercial scale.
Several years before anyone is at that point, Wave Hub is currently competing to offer testing facilities to designers at earlier stages. It has announced two agreements, and the first will see a device in the water before January. The brainchild of an Irish company, Ocean Energy, it is a buoy that works by allowing water into a central chamber. That squeezes air up to create pressure to turn a turbine.
The unspoken message is that Scotland needs to watch out. Orkney might be years ahead as the world's number one venue for testing wave and tidal devices, but Cornwall is competing on waves. This is at a time of disquiet in the Scottish marine energy industry, as was evident at the Scottish Renewables Marine Energy Conference in Inverness last week. No-one is worried about resources, of course. Scotland has 25% of Europe's tidal power and 10% of its wave power – considerably more than the south of England.
But industry leaders are concerned Scotland is being held back by the UK system that charges electricity producers and consumers to use the transmission network. Unless someone comes up with an answer, they claim, the industry could collapse before it is properly under way.
The system was designed in the electricity privatisation era of the late 1980s, when the only thing that mattered was encouraging production of power close to population centres. To achieve this, the system levies higher charges on producers the further away they are from the south east of England. Those that are based closest to London actually get subsidies on the grounds that they are saving the country money by cutting the need for extra transmission network. Producers in the north of Scotland can pay up to £22 per kilowatt (kW) of capacity; those near London get a subsidy of up to £13 per kW.
For consumers, burdened with about three-quarters of the total cost of transmission, it's the other way round. Although no consumers get subsidies, those in the south-east pay higher charges because their decision to live in a high-population area means that the network is under-used in outlying areas. Rates levied on suppliers to pass on to consumers vary from about £10 per kilowatt hour (kWhr) in Caithness to more than £30 in London.
If this system made sense in the past, it became problematic when renewables moved on to the agenda. Take wind: it makes sense to build most turbines in places that have most wind – such as Scotland. Ever since wind farms started appearing, however, the system has punished them for their choice of location, even though it was not really a choice at all.
The Scottish islands have an additional problem. They do not have the interconnectors to export large quantities of power to the grid. If the islands were going to house wind farms, let alone wave and tidal turbines, interconnectors need to be laid first at the cost of the best part of £1 billion. The system charges separately for local connections beyond the trunk network, so local generators would have to stump up themselves.
Regulator Ofgem looked into these issues several years ago and published the Project Transmit last December. It rejected a solution favoured by the Scottish industry that would have charged all electricity producers the same per kW of installed capacity regardless of where they were in the country, saying it was too expensive. It would cost generators an extra £2.7bn over the next 10 years and cost consumers an extra £6.8bn (though this is only about £11 per annual bill), and would hit the consumers in the north of Scotland, who enjoy the cheapest charges under the current system, the hardest. Ofgem was also worried about creating perverse incentives that would lead to developers putting up big power stations in outlying areas.
INSTEAD, it proposed a revised version of the existing system that basically reduced the charges for renewables and cut the subsidies for power plants in the south-east. It reiterated to the islands that their electricity generators would have to pay for their interconnectors. If they were to get any help, it said this would be better done by the Government.
The islands have been up in arms ever since. Last week, Scottish Renewables (SR) chief executive Niall Stuart used the Inverness conference to redouble demands for a solution, publishing research that showed that the Orkneys would pay £70 million a year in transmission charges compared to only £3m being levied on Cornwall.
He says while mainland developers in Scotland could live with the proposals, "Ofgem's remit under Project Transmit was to facilitate the transition to a low-carbon energy sector".
"Wave and tidal are important parts of that sector," he says. "And there's also 1.4 gigawatts of wind across the three island groups [out of about 10 gigawatts in Scotland as a whole] that will only go ahead if the transmission charges are at the right level."
Andrew Scott of Edinburgh wave developer Pelamis says: "I would not go so far as to say it's the death knell, but it's a considerable barrier to investment. Ultimately the industry will start to look elsewhere."
So far the interconnectors are moving ahead, however, at least on the Western Isles and Shetland. The Western Isles' 450 megawatt (MW) link is closest, having secured the necessary commitment from developers. It is due for regulatory approval next month.
Ofgem's supporters, meanwhile, will see this as a sign that enough companies do still think they can make money on the islands, though higher transmission charges might make the link vulnerable to collapse if costs rise during procurement.
The Shetlands, where SSE and the council are planning a 127-turbine wind farm, is hoping to reach the same stage next year for a 600MW link. The Orkneys are further behind because they have fewer wind-farm plans and marine energy is still in its infancy. Instead, distributor SSE is looking for commitments for a simpler 180MW link with a view to increasing capacity with additional connections later. Meantime, the sense is that no-one is expecting any serious movement from Ofgem.
A couple of technical proposals might make some difference if they are accepted by the industry group thrashing out the fine detail, but SR and its allies are putting more emphasis on trying to persuade the UK or Scottish governments to do something. One option is for the UK Energy Secretary to use legislative powers to vary the transmission rules for a special case like the islands. Another is the Scottish Government offering extra subsidies paid for by electricity consumers.
Nick Oppenheim, a wind-farm developer on Lewis, believes a solution will be found: "On the Western Isles, there are 300MW of consented projects. That's 0.5% of the peak electricity requirement for the whole of the UK.
"The developers on the islands have confidence that greater government, following a number of public statements, will ensure that development on all of the major Scottish island groups will be made comparable with the mainland. That's what's taking developers forward."
Others such as Scott of Pelamis are less sanguine, pointing out that Project Transmit was supposed to fix this problem but looks to have failed. He says it needs to be addressed as a matter of urgency to make it easier for island-focused renewables developers to get the money they need from investors to see their projects to fruition.
With the likes of the Cornwall Wave Hub progressing steadily, patriotic loyalty is unlikely to mean much once economic reality comes to a head.