Power From the Oceans
Jan 02 - Futurist, The
Wind energy industries are growing, and as we look for alternative power sources, the growth potential is through the roof. Two industry watchers take a look at generating energy from wind and wave action and the potential to alter the energy landscape.
The prospects for ocean-based renewable energy development look brighter all
the time. Current and potential markets for offshore wind, wave energy, and
tidal power are all expected to show considerable growth over the next five
years.
Offshore wind systems use turbines to generate electricity. Wave systems use
floating rafts or devices fixed to the ocean floor and harness the energy
generated from bobbing or pitching. Other wave- energy approaches include
devices that use the rise and fall of water in a cylindrical shaft to generate
electricity and shoreline devices that channel waves into reservoirs to
concentrate wave power.
Tidal-energy power traditionally involves erecting a dam across the opening
to a tidal basin. The dam includes a sluice that is opened to allow the tide to
flow into the basin. The sluice is then closed, and as the sea level drops,
traditional hydropower technologies can be used to generate electricity from the
elevated water in the basin.
An analysis of the potential market for offshore renewables shows a growing
industry promising to supply energy for millions of people. For the entire
sector, we project 5,800 megawatts (MW) of installed capacity between 2004 and
2008, of which 99% will be in the form of offshore wind farms. Because the wave
and tidal-energy industries are younger and less well developed, it will take
until at least 2010 for these industries to take off. During that period, we
expect to see the value of the market increase by nearly $3 billion a year.
Again, most of that will occur through offshore wind projects.
Photos opposite:
A: The United Kingdom's first offshore wind farm, Blyth Offshore. Each of its
30 turbines can generate 1.5 megawatts of electricity, enough to supply the
annual electricity needs of 41,000 households.
B: Technicians work on the root-end section of a 40-meter blade. When
erected, these structures will be the rotor blades for wind turbines for
offshore wind farms off the British coast at 15 new sites.
C: This "Wave Hub" off the coast of Cornwall, United Kingdom, will
test how well wave machines produce power before they start producing on a
commercial basis. The "Wave Hub" consists of an underwater cable
connected to the national grid and extending some nine miles out to sea.
D: This sea-based turbine, installed at North Hoyle off the Welsh coast in
2003, was for the first large-scale offshore wind farm to be built in the United
Kingdom.
E: The Sea Snail, a turbine for generating tidal energy, can be installed in
shallow and deep water. Professor lan Bryden of the Robert Gordon University in
Scotland stands next to a scale model of the Sea Snail, developed to exploit the
massive energy potential that exists in the firths, lochs, and inter-island
channels of Scotland and nearby isles.
Offshore Wind
Currently, Europe is the only region in the world with any operational
offshore wind capacity; it is expected to have 88% of the new capacity over the
coming five years. European countries increased capacity more than fivefold in
2003 alone, with Germany and the United Kingdom leading the way. These countries
will account for 66% of projected capital expenditures between 2004 and 2008,
with Germany, buoyed by many large and expensive deepwater projects, dominating
the market.
As technology improves, Europe can expect to achieve large strides in
capacity using proportionally fewer turbines. Long-term signals are good for the
U.K. market. Despite a very promising future forecast, an air of uncertainty
hangs over Germany, which is dependent on large, technologically challenging
projects. In Denmark, where a lack of government commitment is deterring
potential developers and investors, only one project is scheduled for
installation by 2008.
The North American market lags approximately five years behind Europe, but it
is expected to increase capacity and become prominent in the market after 2007.
Offshore wind has a potentially large market in North America, but it could
easily fail before it gets a chance to take off. Success of early projects,
particularly in the United States, is critically important in the face of
uncertain planning regulations for offshore wind. In Canada, there are fewer
immediate projects, but the long-term view is more positive. If the flagship Nai
Kun project off Prince Rupert in British Columbia is successful, then it could
be the first of many such wind farms.
The United States has considerable offshore wind potential, but regulation
remains a source of concern. Cape Wind Associates' controversial project off the
coast of Massachusetts is considered critical to the future of offshore wind in
the United States. Its success or failure is likely to set a precedent for
future developments in the country. If regulators approve this wind farm, new
and existing players are likely to take advantage of the potential and generate
many proposals for new projects. On the other hand, if regulators reject the
project, and effectively cancel it, the consequences could be dire for the
entire U.S. industry.
The United States has other significant projects in the planning stages, many
of which are speculative and not expected to arise until the end of the decade.
Ultimately, however, the U.S. government will determine the rate of progress for
these projects. Structured and targeted development plans could boost
offshore-wind developments, but the current U.S. planning system is too
fragmented to support large-scale expansion.
For the offshore wind industry to grow, the United States needs to establish
a comprehensive offshore management system with clear procedures, because at
present there is no set precedent for applications. The success or failure of
projects such as Cape Wind will dictate the terms by which future projects will
be judged.
Wave Power
A number of successful wave-energy devices have been installed at shoreline
locations, but the true potential of wave energy will only be realized offshore
where large developments are conceivable. At present, nearly 300 concepts for
wave-energy devices have been proposed, but because of the difficulty of
developing an efficient, reliable, and cost-effective wave-energy converter,
fewer than 10 are likely to meet commercial demands by the end of the decade.
Commercial wave energy will grow on the back of modular offshore wave-energy
devices that can be deployed quickly and cost- effectively in a wide range of
conditions. In the coming decade, we anticipate that wave energy will become
commercially successful. Opportunities for expansion of the offshore market are
expected to increase in part because the growth of shoreline wave-energy devices
will be increasingly limited by the low number of available sites and by high
installation costs.
Although offshore locations offer greater power potential than shoreline
locations, offshore devices are more difficult to access for maintenance
purposes. Improving the reliability and accessibility will be critical to the
commercial success of the many devices currently under development. Furthermore,
more wave-energy projects will need to be connected to a power grid.
Wave energy will, however, continue to be relevant, accounting for
approximately 25% of capacity forecast over the next five years. Indeed, it is
the most promising sector into the long-term future.
Although several wave-energy devices are getting closer to full- scale
deployments, real-world operation remains limited. Large- scale demonstrations
are required in order to test survivability and efficiency issues. Though it is
difficult to assess potential of a system until it is tested in its final state,
some industry leaders have implemented programs slowly building up to
commercial-scale deployments. Realistically, only a tiny proportion of
wave-energy concepts will move on to a commercial level. Limited resources, in
many cases, hamper the launch of technology, as the sector is dominated by small
and medium enterprises unwilling to collaborate because they wish to protect
their investments. Needed collaboration and cohesion could be aided if regional
and national organizations, such as the British Wind Energy Association, were to
take a more active role.
The United Kingdom is expected to be the dominant player over the next five
years, with a forecast capacity of about half the market share, thanks in large
part to financial support from government grants. The result is a number of
advanced wave technologies with good prospects for deployment. Coupled with a
worldclass natural resource, the United Kingdom could be the undisputed world
leader in wave energy by 2008. The U.S. market shows encouraging levels of
interest in wave technology; however, the market will be affected by the lack of
positive government involvement.
Overall, wave energy will see a total expenditure of $111 million through
2008, with the total U.K. expenditure ($72 m\illion) expected to be more than
all other countries combined.
Capturing the Force of Tides
Historically, tidal projects have used large-scale barrage systems to block
estuaries. Within the last few decades, developers have shifted toward
technologies that capture tidally driven coastal currents (the tidal stream).
Very large amounts of energy are available in coastal waters. The challenge is
"to develop technology and innovate in a way that will allow this form of
low-density renewable energy to become practical and economic," according
to Tony Trapp, managing director of The Engineering Bureau Ltd.
Right: The 750-ton Pelamis Wave Energy Converter is the world's first
commercial machine that can harness the energy from ocean waves to produce
electricity. Here it is being towed to its launch off the coast of Scotland.
Below: These turbines will be used to produce renewable energy from tides.
This unit will rest on the seabed at a depth of some 60 meters, where it will
reap the full benefit of tidal flow while avoiding potential damage from storms
and violent surface waves.
At present, smaller units that can be deployed individually or in multiple
units characterize tidal-current-stream technologies. Two types of technologies
are in operation or are planned: tidal- current turbines and tidal-stream
generators. Tidalcurrent turbines are basically underwater windmills where
currents rotate underwater turbines, ideally within a kilometer offshore in
depths of up to 30 meters. First proposed during the 1970s oil crisis, the
technology has only recently become a reality. One company, Marine Current
Turbine (U.K.), installed the first full-scale prototype turbine off Lynmouth in
Devon in 2003. Shortly thereafter, the Norwegian company Hammerfest Str0m
installed their first prototype device.
Tidal-stream generators use the tidal stream to generate power from, for
example, the raising and lowering of a hydraulic arm. Several very promising
devices are at an advanced stage of development. For example, The Engineering
Bureau has developed and tested a simple concept of placing hydrofoils in the
tidal stream to produce an oscillatory motion in the vertical or horizontal
plane. The device, known as the Stingray Tidal Current Generator,
"transforms the kinetic energy of the moving water into hydraulic power,
which turns a generator by means of a hydraulic motor," Trapp explains.
We anticipate that multi-megawatt farms will emerge by the end of the decade.
By 2008, a total of 14.8 MW capacity is expected, with 65% of the capacity in
the United Kingdom. Norway, which already has installed capacity, will be the
second dominant player, but lacks defined projects over the next five years.
Other countries (Canada, France, and the United States) will play only minor
roles. We anticipate almost 70% of forecast capacity by 2008 from tidal- current
turbines and approximately 30% from tidal-stream generators.
Capital expenditures for tidal energy will reach $35 million by 2008, with
the United Kingdom as the biggest market ($23 million) and Norway second ($10
million).
The Future of Ocean-Based Power
While success in 2003-2004 has been high, much of the promised capacity has
failed to materialize because of problems across the board. However, a number of
countries have made significant progress in the sector, most visibly the United
Kingdom, which now has more approved offshore wind capacity than any other
country and leads the world in planned wave and tidal-current-stream capacity.
Wave and tidal energy will grow in importance during the next five years, but
they are overshadowed by the massive offshore wind sector. Progress in wave and
tidal energy has been extremely encouraging over the last year, and in the near
future a number of further key developments are set to take place. Within the
five- year period ahead, we will see a number of technologies reach commercial
application and be installed in multiple-unit configurations. In this respect,
these developing industries can be seen as being at a stage similar to offshore
wind a little more than a decade ago. With time and sufficient encouragement,
sizable wave and tidal farms could be in place by the next decade.
It is becoming clear which countries are paving the way for an increased
offshore renewables energy share, by creating the necessary market conditions
and supporting projects from their outset through to realization. Commitment to
renewables, especially offshore, must be sustained over the long term or the
market will founder. Although the level of installed capacity is growing quickly
and the proposed number of projects is ever growing, the fragility of the entire
industry is evident through project failings and aboutturns by countries that
have lost the will to foster the industry.
The world's first commercial wave machine-the oscillating water column-on the
Isle of Islay, Scotland. This system supplies power to the island grid, playing
a crucial part in enabling lslay to displace fossil fuels and become
self-sufficient using renewable energy.
The United Kingdom is a particularly important market for the three offshore
renewables sectors. Driven by a world-class natural resource, this country has
experienced notable successes in wind, wave, and tidal energies. Offshore wind,
in particular, has generated much attention, as the United Kingdom's first major
offshore wind farm has been installed and the second is nearing completion. With
more approved offshore wind capacity in the planning stage than any other
country, the United Kingdom has bright prospects. The system of offshore leases
has shown a structuring that is lacking in other countries. Recent decisions to
extend renewable energy portfolio targets to 15.4% by 2015 have provided a
signal of long-term commitment. This sustained outlook is crucial to offshore
renewables-not just offshore wind, but the growing wave and tidal sectors as
well.
In the United Kingdom, the domestic offshore renewables industry is set to
develop on the back of the high level of prospects, but challenges from other
European countries where renewables, particularly wind, are more established
should not be discounted. The United Kingdom has a large manufacturing sector
and a highly skilled oil and gas workforce that will be able to diversify into
offshore renewables as the industry grows.
Worldwide, the value of the market over the next five years is projected at
$9.6 billion, growing from $276 million a year in 2004 to nearly $3 billion a
year by the end of the period. Growth between 2004 and 2008 is forecast at more
than tenfold. By the end of the period, costs per megawatt will have fallen
noticeably, making offshore renewables increasingly viable.
At $150 million, wave and tidal power will only be a small percentage of the
total expenditure in offshore renewables. However, wave and tidal power
currently attract higher expenditures per megawatt. This indicates higher costs
of these developing industries. These costs will fall as time goes by and the
industries progress. The leading devices should be comparable to offshore wind
by the end of the decade.
The dominance of offshore wind does not mean wave and tidal energy are not
important; they are just less well developed, and the industry is much younger.
From around 2010, wave and tidal could begin to experience equally rapid growth.
We have based our analysis of marine renewable energy on identified projects.
The forecasts are conservative-the prospective markets could be far larger as
technology advances and as regulatory environments improve.
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About the Authors
Anthony T. Jones is an oceanographic consultant with oceanUS consulting in
San Francisco, offering forecasts in ocean energy systems development. His
address is 22 Battery Street, Suite 401, San Francisco, California 94111. E-mail
tony@seavolt.com .
Adam Westwood is an analyst with Douglas-Westwood Ltd., Canterbury, United
Kingdom, providing business intelligence for the renewable sector, including an
offshore wind database. His address is St. Andrew's House, 2nd Floor, Station
Road East, Canterbury CT1 2WD, United Kingdom. E-mail adam@dw-1.com.
Copyright World Future Society Jan/Feb 2005