For most of us power from the sea means watching waves crashing on a beach or smashing up against a breakwater. But if you want to experience wave power at its most energetic then you need to be offshore. In fact you need to be over one hundred kilometres offshore.
In February 2000, a British oceanographic research vessel sailing in the Rockall Trough, some 180Km from land, encountered the largest waves ever recorded by scientific instruments in the open ocean. The boat recorded individual wave heights some 29m high from crest to trough. That's three times the height that Tom Daley dived at during the London Olympics.
The findings of that research vessel come into sharp focus given the on-going debate about where the UK is going to find secure, low carbon and affordable energy from in the coming decades. For wave power to play its part our latest analysis has shown we need to get the technology pretty close to where that research vessel was twelve years ago. That means heading West off Lewis, out to the edge of the UK's continental shelf, just before the Rockall Trough and stopping. That's some 150km offshore and in water a few hundred metres deep. Here represents one of the best spots to harness the UK's wave resource at potentially the lowest cost.
The research has found that if we were to put a line of some 1,000Km of wave devices from the edge of the Rockall Trough over the top of Scotland we would be able to generate almost 100TWh of electricity a year. That's equivalent to 25% of the UK's current electricity needs. About half of that we believe can be harnessed economically if further advances are made in innovating the technology over the coming decade.
In fact our research has revealed that these sites are so energetic that they have the potential to generate energy at the costs needed to be competitive with offshore wind, nuclear and other low carbon energy sources. All this sounds great. But there's one major problem. We don't yet have commercial devices that have been built and tested at the scale needed to operate in such hostile and remote environments. But we may not be waiting for too long.
Over the past few years, backed by consistent policy and innovation support from both the UK and Scottish Governments, the marine energy sector has been quietly taking major steps forward and is on the edge of taking a few more. The UK has become the world's proving ground for wave and tidal energy with the bulk of the world's wave energy devices being developed in the UK with many already at, or awaiting a berth, at EMEC, our world leading testing site in the Orkneys. This is not surprising given 50% of Europe's total wave resource is located in our territorial waters. But having the resource is one thing. What must be done to drive costs down to the point where wave power is on an equal footing with offshore wind and other low carbon technologies?
Well the first and foremost we must recognise this is a long term game, and we must hold our course. The industry needs a stable supportive backdrop against which to develop, including a clear long term commitment from government with regards to revenue support. Continued commitment of large manufacturers and utilities to the sector is also critically important. The current set of financial incentives provides reasonable assurance that commercial size arrays of some 5MW will be in the water and generating power by 2015. This will take us through to full scale demonstration - or the 'proof of scalability.' And this is critical.
We have estimated that these first 5MW wave arrays will generate electricity at around 35-40p/KWh; more than two times the cost of offshore wind. But cost is not the primary driver for these first arrays; we must demonstrate that they are durable. The next step will occur between 2016 and 2020 at sites licenced by the Crown Estate around Pentland Firth and Orkney. By then, if things go well, and private and public finance stays in the game we expect wave energy to reduce in costs pretty dramatically and to be generating at some 20p/KWh.
At that point we will be in a much clearer position to know whether the energy on the edge of the Rockall Trough is in sight or will remain out of reach. By taking advantage of such energetic sites offshore our initial analysis indicates that the costs can potentially go lower to some 10p/KWh making it competitive with other low carbon energy sources.
The promise is huge and in a carbon constrained world providing a tenth of our power needs from wave energy offers obvious advantages for us. But the benefits are not just environmental. As economic growth continues to be elusive power from the waves could also help power up the UK economy. The International Energy Agency has estimated a global market of up to 200GW of marine power by 2050. If the UK were to capture some 15% of this the UK economy would receive a £4 billion benefit. Now that's even more of a reason for us to get serious.