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.