Status and Prospects of Marine Energy Technologies: Rapid Expansion and Cost Reduction in View

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2. There are many interesting marine energy technologies –
including, as you know, wave, tidal and ocean thermal.
Within each technologycategory,there is a large variety in
turbine designs (see pictures of Seagen(left wit two different
mooring systems),Alstom top right, open hydro and Sabella
in bottom middle and bottom right). In tidal energy, at least a
converging towards horizontal axis but wave energy still a lot
of diversity.
The diversity is both positive and negative. Increases risks by
projectdevelopers as there is limited comparative information on
what turbine performs bestunder certain circumstances.On the
other hand, variety raises competition.
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3. Because these marine energy technologies are of real interest,
IRENA has prepared technology briefs, which can be downloaded for
free from our website. Ocean thermal energy conversion, salinity
gradients, tidal and wave options are all covered. The briefs describe
how the technologies work, list current and planned projects,
document costs and performance, and assess future potential, taking
account of technical, economic and financial drivers as well as
available resources. Over the time that it took to write the report,
deployment numbers changed, new technologies entered the market,
and old ones disappeared. We therefore relied extensively on experts
and researchers in the field, and we had three rounds of review
processes to ensure that all the information was up to date. IRENA
Member countries were also of great help as they identified key
experts in their countries for IRENA to rely on.
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4. Here, you can see the different marine technologies on a scale of
technology readiness. Tidal range technology, shown at level 9 on the
right edge of the diagram, is fully operational over a wide range of
conditions. Tidal stream and wave energy technologies have received
the greatest focus in our assessment, since they are the technologies
still under development that are closest to being commercial. Tidal
stream projects have reached the full scale or prototype demonstration
stage (number 7) in a variety of locations which are representativie of
potential commercial sites, already generating electricity on actual
power grids. Wave energy converters have reached the pilot-scale
prototype phase (number 6 on the scale), with full-scale prototypes
being tested in an actual working environment. OTEC, or ocean
thermal technology, is well past the laboratory stage (number 5), but
OTEC pilot scale facilities have not been scaled up beyond 1MW yet.
The deep ocean current and salinity gradient technologies are still at
laboratory scale.
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5. Corresponding to their more advanced stage of development,
wave and tidal stream technologies have so far received far more
patents than the other marine energy technologies we evaluated.
Tidal energy patents are dominated by the UK (16), followed by
Germany, france (5), Canada, US, Japan, Korea (4). 60% of patents
are filed by companies.
Wave energy patents are more global. US (13), China (10), Spain and
UK (6), but also in Korea, South Africa, Russia, India, chile. Split 50% -
50% between individuals and companies.
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6. In the short term, the wave and tidal stream technologies are the most
attractive, based on industrial involvement and financial investment to
date. But OTEC is also highly attractive for further development in view
of its global physical resource base.
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7. For all three technologies, what is most notable is the rapid expansion
of pilot projects from a very small base. Between the 2013 base year
of our study and 2018 – the cumulative capacity is is expected to
expand more than 6-fold for wave energy, 12-fold for tidal energy, and
from a couple of kW to 20 MW (two plants) for OTEC.
However, in the last year BNEF as well as the ocean energy industry
has downgraded their expectations.
We know from development of wind and solar technologies that a
doubling of cumulative capacity will typically result in a cost reduction
of something like 20 per cent, though the learning curve is different
for each technology. So with 3 or 4 doublings over a 5-year period, it
would not be surprising to see costs cut in half.
It is therefore important that despite high costs, demonstration projects
are continued.
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8. Indeed, we anticipate that the cost could decline by 2020 (just 5 years
away) to a range of 13 to 26 cents per kWh for wave energy, 21 to 25
cents per kWh for tidal stream, and from 19-33 cents to 10 cents per
kWh for OTEC.
Salinity gradient cost reductions are highly speculative, because only
one demonstration plant of a couple of kW exist today. The tidal range
figures shown are quite low because they assume facilities are added
to existing dams, and the costs already sunk in the existing
infrastructure aren’t counted; greenfield construction might cost more
like 14 to 23 cents per kWh.
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9. We also looked at a variety of technical, economic and institutional barriers to
be overcome for each technology.
One of the key messages of our analysis is that we are the brink of larger
scale deployment. The technologies are demonstrated at pilot scale, but
utility-scale plants are needed to provide the experience and confidence for
further deployment. Policy makers play a key role in ensuring that this final
push is made.
Coherent and consistent resource assessments, along with high-quality
measurements of potential at specific sites, can play a key role in commercial
development of the technologies. And we need to carefully consider potential
impacts on the environment to ensure that projects can proceed on a sound
and sustainable basis without encountering avoidable delays.
We also need to better understand the complex barriers to deployment of
marine energy technologies and work together to create the enabling
conditions to unleash their potential. If we can agree on roadmaps for
technology development and commercialisation, including suitable policy
goals and measures, cost and risks can be substantially reduced. And if
policy makers are made more aware of the wide variety of potential
applications - such as cooling, water desalination, sustainable tourism and
aquaculture - they are more likely to provide the support that is needed to
accelerate deployment.
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10. In the effort to commercialise ocean energy applications, we need to be
realistic about what is possible over any given time scale. With a strong
vision, broad cooperation and pragmatic planning, however, we can
increasingly tap into the abundant, clean, secure energy that is stored
in the oceans of the world.
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