APPENDIX 6
Memorandum submitted by the Open University
Energy and Environment Research Unit
WAVE AND
TIDAL ENERGY
We have responded to the suggested questions
separately for wave and tidal energy.
WAVE ENERGY
1. Technological viability: Is the technology
available for efficient generation of power from waves?
The 500kW "LIMPET" gully mounted shore-line
Oscillating Water Column (OWC) device is now operating on Islay,
and feeding power to the grid under an SRO contract. It follows
on from the 75kW prototype there.
Two more advanced offshore devices were also
supported under the SRO and are currently under development—the
Pelamis "sea snake" and the Swedish floating TAPCHAN
platform—and should be installed at sea in 2002.
Several other offshore devices are under test
elsewhere in the world, notably the Dutch Archimedes Wave Swing
and the Danish Waveplane. Scale models of both of these devices
have already been tested at sea, and a full-scale system should
be installed in 2002.
A 500kW version of the Australian Energetech
shoreline wave-funnelling device is being installed at Port Kembala
in New South Wales.
The Norwegian TAPCHAN reservoir system, which
has been in operation for many years on a coastal site in Norway,
seems likely to be adopted quite widely in suitable areas in the
developing world.
Consequently, it would appear that, while new
ideas continue to emerge, wave energy technology has developed
beyond the research stage for some devices and is becoming a viable
technological option.
2. Commercial viability: Will wave energy
become commercially viable in the near future, and attractive
to the private sector as a profitable investment?
The LIMPET shoreline device is a commercial
generator supplying power to the grid under an SRO 2 contract,
which offered between 5.75-7p/kWh to three wave projects, with
the Limpet presumably falling at the low end of this range. The
Australian Energetech device, which is claimed to be more efficient
and cost effective, is expected to generate at around 4p/kWh (initially
A£0.15/kWh, with refinement A£0.05/kWh).
With further development it seems possible that
wave energy devices could become more competitive. In ETSU's report
R122 (March 1999), the cost resource curve, at 8 per cent discount
rate, cut the x-axis at 3p/kWh, and there was estimated to be
a resource of around 32TWh at 4p/kWh, well within the price limit
resulting from the cap proposed for the Renewables Obligation.
3. Current projects: What projects are currently
running in the UK and how successful have they been? Why did past
projects fail?
Wavegens LIMPET is the only project actually
operating at present in the UK. Their earlier offshore "Osprey"
device suffered damage when it was launched in August 1998 and
was subsequently wrecked by an unseasonal storm before it could
be fully ballasted with sand.
Several other scale prototypes were tested at
sea during the early days of the UK wave programme (eg the Cockerell
raft, the Salter Duck, the Lanchester SEA Clam). None failed,
but the deep-sea R&D programme was terminated following the
ACORD/ETSU review in 1982. Shoreline work was also would up following
a subsequent review. The current UK projects are private/EU/SRO
supported survivors.
4. Renewables strategy: What role should wave
energy have in the Government's renewable energy strategy? Should
they be a higher priority?
Wave power devices might ultimately supply up
to 20 per cent of UK electricity with minimal environmental impacts.
Given the UK's maritime history and its extensive offshore engineering
experience coupled with the major energy resource offshore, it
would be perverse to ignore this option. The OST Marine Foresight
panels positive review in 1998 led to wave power being shifted
from the "very long term category", in the DTI ranking,
to "long term". We feel this represents a much too cautious
approach to what could be a major energy (and employment) option
for the UK.
In response to the Marine Foresight report,
when he was Energy Minister, John Battle said that he would "expand
the objectives of the Department's New and Renewable energy programme
to include new work on wave energy technology". However,
so far as we know, no new DTI funding allocations have yet been
made.
The Royal Commission on Environmental Pollution,
in its study of Climate Change and UK Energy Policy, included
a series of scenarios in each of which there was 7.5GW of wave
energy generating capacity installed by 2050. We would see this
as the minimum to be aimed for.
5. Research and development: What Research
& Development is being undertaken at present? How much funding
is available and how easy is it for innovative ideas to gain support?
Is national funding for R&D being well co-ordinated? What
sort of peer-review processes is undertaken?
As far as we know, UK funding is limited to
the small residual DTI R&D allocation and to support from
the Research Councils, plus of course the operational subsidy
provided by the three SRO contracts in Scotland, which will presumably
have to be renegotiated as and when the Scottish version of the
Renewables Obligation comes into force. In addition there has
been EU funding for some projects, including Salter's various
devices, the LIMPET and Osprey.
Overall the funding thus seems to be at a very
low level, and from a range of sources with different perspectives
and timeframes, and, we would assume, given the lack of an overall
wave energy strategy, poorly co-ordinated. In this context we
welcome the establishment last year of a "Commission for
Wave Power in Scotland", bringing together MSP, trades unionist,
wave energy developers and academics.
6. Environmental aspects: What are the environmental
implications of wave energy, particularly for marine life? How
will such devices affect shipping?
In its various reports on Wave Power, ETSU included
comments on environmental impacts (eg Energy paper 42, 1979; ETSU
R26, 1985). In general the impacts seem to be relatively small.
Certainly that was the view expressed by Professor Stephen Salter
in a more recent review paper (International Journal of Ambient
Energy, Volume 14, No. 1, 1993). The main environmental (and
indeed cost) issues are likely to be in relation to the need for
new grid links from the landfall site to the nearest main grid
connection points.
7. International comparisons: How does Britain
compare with other comparable nations in R&D in this field?
What projects are currently being undertaken abroad and how successful
have they been?
As noted above Denmark, the Netherlands and
Australia all have significant ongoing wave energy projects, as
does Japan, Norway, Portugal and the USA.
The Danish programme is one of the largest.
It involved a DKK 20m (£2m) allocation for 1998-99, with,
we believe, a similar amount for 2000-01. So far around 20 concepts
have been assessed with several passing through the first stage
of assessment, including the Waveplane, the Dragon and the Swan.
Japan has installed many small OWC devices on
breakwaters and has a floating offshore test rig, the so-called
Mighty Whale, which has 110MW of OWC on board. It has been on
test in Gokasho Bay since 1998.
Portugal has installed a 500Kw OWC on the island
of Pico in the Azores. Norway is exporting its TAPCHAN wave topped-up
reservoir system around the world. For example, it has installed
one in Java and Chile, India and Sri Lanka have showed interest
in it. Norway is also working on various other devices, and Statoil
has been considering the use of wave energy devices for power
generation of its oil platforms.
US developments include a very ambitious device
using deformable piezo-electric polymer to generate power. There
are many other smaller projects around the world including one
in Israel for desalination.
Clearly, wave power is of considerable interest
around the world, with one of its first widespread applications
being likely to be the provision of power for remote off-grid
islands in the developing world. However, although there are many
good sites off Japan and Australia, the main wave resource is
the North Atlantic—with the UK being particularly favoured.
In this context, it would be tragic if the UK, one of the main
initial pioneers of wave energy, continued to downplay this energy
option, and then had to import equipment from overseas.
SOURCES
The European Wave site is at: http://www.ucc.ie/ucc/research/hmrc/ewern.htm
The Danish site is at: htpp://www.waveenergy.dk
The Norwegian site is at: http://www.phys.ntnu.no/glos/grupper/stralbol/bolgegrp-e.html.
Details of Japan's "Mighty Whale"
can be found at: http://www.jamstec.go.jp/jamstec/MTD/whale
The wave energy group at Edinburgh University
has a site as: http://www.mech.ed.ac.uk/research/wavepower/index.htm
Wavegen, the pioneering UK company, has a site
at: http://www.wavegen.co.uk
TIDAL ENERGY
1. Technological viability: Is the technology
available for efficient generation of power from tides?
Many tidal mills operated in the UK and elsewhere
on rivers and estuaries in the Middle Ages. There was a device
for turning machinery on Three Mills Island in the river Lea now
in London for many centuries.
Modern interest in harnessing tidal currents
has only emerged in the past 30 years. The Intermediate Technology
Development Group developed designs for floating tidal devices
for use in developing countries in the 1970s, but the major breakthrough
came with IT Power's Tidemill concept in the 1980s/1990s—essentially
an inverted wind turbine-like device immersed in the flow. A 10kW
rated prototype was successfully tested in Loch Linnie in 1994,
with support from Scottish Nuclear. It actually developed some
15kW in a 2.25m/s current.
In this prototype, the rotor unit was suspended
from a floating buoy and in full operation would be anchored to
the seabed by cables. However, IT Power now favour a fixed mounting,
on a monopile driven into the sea bed, and a 300Kw part EU funded
version is currently being installed off the coast of Devon near
Linton. The next stage is a 600kW commercial model, followed,
if all goes well, by a 10MW array of devices, with the projected
target installation date being 2003.
Less well advanced is the Active Water Column
device, being developed by the Engineering Business in Northumbria—this
essentially being a version of the Oscillating Water Column wave
device with rotatable fins added to translate the energy in the
horizontal tidal flow into vertical movement. The company has
also developed a design for a multi-vane seabed mounted device
called the Stingray.
In addition, Professor Stephen Salter at Edinburgh
University has developed a design for a novel floating circular
device nicknamed the Polo.
There are other tidal current devices under
development elsewhere in the world, most notably the tidal fence
technology developed by Blue Energy of Canada. This consists of
a series of vertical axis turbines mounted in an array. A 100kW
prototype was tested in the 1980s, and a 500kW pre-commercial
unit is being installed at Sonara Island off the coast of British
Columbia. There are plans to build a full scale 50MW tidal fence
in the Phillipines (by 2003), to be followed, if all goes well
and the funding is available, by a 2.2GW array in a causeway between
two islands there.
Even more ambitious, is Dr Alexander Gorlov's
plan to use another type of vertical axis turbine, in a submerged
lattice array, to harvest energy from the Gulf Stream off Florida.
Clearly some tidal current devices are still
at the research stage, but some are beginning to move on to large
scale demonstration, and some have moved almost to the commercial
stage.
2. Commercial viability: Will tidal energy
become commercially viable in the near future and attractive to
the private sector as a profitable investment?
As noted above, most tidal stream/current devices
are still at the research or development stage, and prices are
still speculative. But studies by IT Power have indicated that
the generation cost of a full scale version of their system might
be 6p/kWh for a cluster of eight turbines of 20m diameter assuming
an on site load factor of 50 per cent, a 15 year life time and
discount rate of 5 per cent. However, prices could fall and experience
develops and the technology improves. IT Power have talked of
moving to commercial production by 2004.
Certainly there is a significant resource available
in the UK—an early ETSU study (Tidal Stream Energy Review
1993) put it at up to the equivalent of 19 per cent of UK electricity
consumption, while a more recent ETSU report (ETSU R122, March
1999) suggests 36TWh by 2010 from 322 MW installed. For comparison,
the overall European resource has been put at 50TWh/yr from 106
sites studies so far.
It is interesting to note that the tidal current
cost-resource graph in ETSU's report R122 cuts the axis at 1.5p/kWh
(for 1020 at 8 per cent discount rate). Although there would only
be a small resource available at around this level, it expands
to around 0.7TWh at 2p/kWh. This resource seems to be what Professor
Stephen Salter is hoping to exploit with his Polo device. If successful,
this could well provide the niche from which tidal stream technology
could expand.
Blue Energy has also looked at the UK as a possible
site for their technology and has indicated that the Severn Estuary
might be suited. They seem confident that their technology could
be economically viable even with tidal flows of less than 2m/s.
3. Current projects: What projects are currently
running in the UK and how successful have they been? Why did past
projects fail?
As noted above the only UK project currently
on line (or just about to be) is the IT Power device being installed
off Linton in Devon. The other UK projects are at the design and
research stage.
4. Renewables strategy: What role should tidal
energy have in the Government's renewable energy strategy? Should
they be a higher priority?
Tidal power devices might ultimately supply
up to 20 per cent of UK electricity with minimal environmental
impacts. As with wave power, given the UK's maritime history and
its extensive offshore engineering experience coupled with the
major energy resource offshore, it would be perverse to ignore
this option.
The Marine Foresight panel review in 1998 noted
that the technology was still undeveloped but suggested those
marine current systems could take a measurable market share by
2020.
However, the DTI seems to have not even included
tidal stream technology in its "very long term" category
in its ranking. Thus only tidal barrages are mentioned in the
"very long term" category in the DTI's 1999 consultative
paper on the New and Renewable Energy programme, and this categorisation
remained unchanged in the DTI's subsequent "conclusions in
response to the public consultation" published in January
2000, despite submissions (including our own) calling for a rethink.
The Royal Commission on Environmental Pollution,
in its study of Climate Change and UK Energy Policy, included
a series of scenarios in each of which there was 500MW of tidal
stream generating capacity installed by 2050. We would have thought
that this was very pessimistic—unless funding stays at its
present very low level.
5. Research and development: What Research
& Development is being undertaken at present? How much funding
is available and how easy is it for innovative ideas to gain support?
Is national funding for R&D being well co-ordinated? What
sort of peer-review processes is undertaken?
As far as we know, UK funding is limited to
a very small DTI allocation for the Active Water Column (£50,000
under the Smart programme) and to generic support from the Research
Councils. In addition there has been matching EU funding for IT
Power's new project.
Overall the funding thus seems to be at a very
low level—so low that co-ordination is hardly an issue.
6. Environmental aspects: What are the environmental
implications of wave energy, particularly for marine life? How
will such devices affect shipping?
Some preliminary studies have been carried out
of the environmental impact, as reported in ESTU's 1993 Tidal
Stream Energy Review. Generally the impact is seen as likely to
be relatively small, certainly much smaller than that associated
with tidal barrages. As with wave energy, the main environmental
(and indeed cost) issues are likely to be in relation to the need
for new grid links from the landfall site to the nearest main
grid connection points.
7. International comparisons: How does Britain
compare with other comparable nations in R&D in this field?
What projects are currently being undertaken abroad and how successful
have they been?
As noted above, Blue Energy in Canada have ambitious
plans for major projects and there are some other projects underway
in the USA and elsewhere. However, despite the low level of funding,
the UK has perhaps the most well developed expertise so far.
Although it is not a tidal current device (or
a barrage), it may be worth noting that Tidal Electric, the US
tidal power development company, has proposed a novel offshore
tidal concept, involving the construction of free standing bounded
reservoirs to trap the tides. It is looking at sites around the
world, including sites in Wales—at Rhyl, off the North Wales
coast, which would have a generating capacity of 400MW, and a
smaller 30MW project off the coast near Swansea.
To provide more nearly continuous output, the
reservoir of the Rhyl scheme would be subdivided into segments
with each being filled and emptied in turn. The reservoirs would
be constructed from rocks, as with a causeway. It would not be
a barrage since it would not dam an estuary. If the idea went
ahead it would represent the largest single renewable energy project
in the UK.
Novel ideas like this suggest that there may
be new ways to develop the tidal barrage concept. Indeed we feel
that there could still be merit in conventional barrage concepts,
given that the technology does not develop, a view shared it seems
by the Royal Commission on Environmental Pollution, which, in
its recent report, included the Severn Barrage in its scenarios.
SOURCES:
http://www.marineturbines.com
http://www.engb.com
http.//www.bluenergy.com
http://www.tidalelectric.com
January 2001
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