Japan has excellent scope for offshore wind power.
Cannot. At best Renewables can supplement conventional power but cannot replace the latter. Several countries in Africa,Asia and Latin America have least impact of Renewables.I am nether an optimist nor Pessimist but realist.
Great research. Future energy option possibility.
Dr. A.Jagadeesh Nellore(AP),India
Excellent article on Floating Wind Farms.
The concept for large-scale offshore floating wind turbines was introduced by Professor William E. Heronemus at the University of Massachusetts Amherst in 1972. It was not until the mid 1990s, after the commercial wind industry was well established, that the topic was taken up again by the mainstream research community." As of 2003, existing offshore fixed-bottom wind turbine technology deployments had been limited to water depths of 30 metres. Worldwide deep-water wind resources are extremely abundant in subseaareas with depths up to 600 metres, which are thought to best facilitate transmission of the generated electric power to shore communities. Two-thirds of the North Sea is between 50 and 220 meters deep
Operational deep-water platforms
In 2011 three floating wind turbine support structures were installed.
Blue H deployed the first 80 kW floating wind turbine 21.3 kilometres (13.2 mi) off the coast of Italy in December, 2007. It was then decommissioned at the end of 2008 after completing a planned test year of gathering operational data
The first large-capacity, 2.3 megawatt floating wind turbine is Hywind, which became operational in theNorth Sea off of Norway in September 2009 and is still operational as of October 2010.
In October 2011, Principle Power's WindFloat Prototype was installed 4 km offshore of Aguçadoura, Portugal in approximately 45m of water (previously the Aguçadoura Wave Farm site). The WindFloat was fitted with a Vestas V80 2.0MW offshore wind turbine and grid connected. The installation was the first offshore wind turbine to be deployed without the use of any offshore heavy lift vessels as the turbine was fully commissioned onshore prior to the unit being towed offshore. Additionally this is the first offshore wind turbine installed in open Atlantic waters and make use of a semi-submersible type floating foundation.
SeaTwirl deployed their first floating grid connected wind turbine off the coast of Sweden in August, 2011. It was tested and de-commissioned. This design intends to store energy in a flywheel. Thus, energy could be produced even after the wind has stopped blowing.
Floating wind parks are wind farms that site several floating wind turbines closely together to take advantage of common infrastructure such as power transmission facilities.
"Technically, the [theoretical] feasibility of deepwater [floating] wind turbines is not questioned as long-term survivability of floating structures has already been successfully demonstrated by the marine and offshore oil industries over many decades. However, the economics that allowed the deployment of thousands of offshore oil rigs have yet to be demonstrated for floating wind turbine platforms. For deepwater wind turbines, a floating structure will replace pile-driven monopoles or conventional concrete bases that are commonly used as foundations for shallow water and land-based turbines. The floating structure must provide enough buoyancy to support the weight of the turbine and to restrain pitch, roll and heave motions within acceptable limits. The capital costs for the wind turbine itself will not be significantly higher than current marinized turbine costs in shallow water. Therefore, the economics of deepwater wind turbines will be determined primarily by the additional costs of the floating structure and power distribution system, which are offset by higheroffshore winds and close proximity to large load centres (e.g. shorter transmission runs)."
As of 2009 however, the economic feasibility of shallow-water offshore wind technologies is more completely understood. With empirical data obtained from fixed-bottom installations off many countries since the late 1990s, representative costs are well understood. Shallow-water turbines cost between 2.4 and 3 million United States dollars per megawatt to install, according to the World Energy Council.
As of 2009, the practical feasibility and per-unit economics of deep-water, floating-turbine offshore wind is yet to be seen. Initial deployment of single full-capacity turbines in deep-water locations began only in 2009.
As of October 2010, new feasibility studies are supporting that floating turbines are becoming both technically and economically viable in the UK and global energy markets. "The higher up-front costs associated with developing floating wind turbines would be offset by the fact that they would be able to access areas of deep water off the coastline of the UK where winds are stronger and reliable."
The recent Offshore Valuation study conducted in the UK has confirmed that using just one third of the UK's wind, wave and tidal resource could generate energy equivalent to 1 billion barrels of oil per year; the same as North Sea oil and gas production. Some of the primary challenges are the coordination needed to develop transmission lines(Wikipedia)
Allied to floating WIND turbine concept is ENERGY island designed by Dominic Michaelis.
With the assistance of Dr Luis Vega, a world expert in OTEC systems, Energy Island has designed a number of OTEC plants based around a 1,8 MW turbine providing over 1MW of electricity, after peripheral losses are taken into account.
Energy Island has carried out a Pre FEED study of 50 MW OTEC plants, with options of open or closed cycles, the former producing 50 MW and delivering 118M litres of desalinated water per day. We have designed platforms and plant ships incorporating these systems.
Energy Island hold a patent, (Patent GB 2395754) for an OTEC low level condenser by which the working fluid vapour is taken down to great depths to be condensed, the liquid fluid being then pumped up to the surface, thus avoiding the cold water pipe bringing up tons of coolant water from 1000 meters or so down, causing replacement water currents with entrainment of micro-organisms, disturbing the ecosystem.
If OTEC is used on a large scale, such a system would limit any negative side effects, making the system much more efficient.
The Energy Island concept is to bring together on a single floating structure a variety of renewable energy conversion systems to maximise the energy production available from the diverse sources available, so that the interrelated systems can assist each other to reach greater efficiencies of conversion.
The Energy Island is designed principally for tropical waters, but variants for higher latitudes can also be considered.
The basic island could be of hexagonal plan, so that it could readily be joined to other units to form cluster or linear plans as required. A hexagon made up of 6 equilateral triangles of 300 meter long sides would have a longest cross distance of 600 meters and a shortest cross distance of 520 meters. Its area would be 234 000 m(2), or 23,4 hectares. It's size would guarantee it's stability in heavy seas.
The Energy Island would act as a platform to maximise collection and conversion of the diverse renewable energy sources available.
These would include :-
WIND ENERGY Wind Energy varies from site to site, but is generally more plentiful at sea, without the interference of land features. In these conditions, to maximise wind energy collection, aerogenerators would be mounted on height adjustable hydraulic masts allowing collection at different heights where one mill would be in the lee of another. On a 600 meter wide platform, it is proposed to place 3 low level 70 meter diameter mills and 3 high level diameter mills, each capable of generating 3 MW (el). The total peak output is 18 MW peak.
SEA CURRENT ENERGY Sea current Energy is very site dependent, but it is assumed that a cowled turbine assembly 500 meters across perpendicular to a constant current flow can generate 2MW / 100 meters, or a total of 10 MW.
WAVE ENERGY Although in tropical waters, the average wave energy profile is far from the 50 kW / meter average of the North Sea, a figure of 15 kW / meter can be expected. Since one of the problems of OTEC systems lies in the vast volumes of water that need to be shifted, wave energy could be used directly to induce these flows without going through the inefficiencies of electricity generation. With a 600 meter long front, a 9 MW resource is achieved, of which it is assumed that 2/3 can be transferred to usable hydraulic power, a 6 MW contribution.
SOLAR ENERGY Many different solar collector systems can be considered over the 22 hectare platform, ranging from PV arrays to concentrating thermal systems. The hexagonal plan lends itself particularly well to "Power Tower" systems in tropical latitudes. The highest collection efficiencies, around 75%, are achieved by such high temperature "Power Tower" type concentrators, which, at 800°C, allow a secondary conversion ratio to electricity of 40%, an overall efficiency of 30%.
Wind Energy Expert
Excellent article on Offshore Wind Farms in US. Yes. US has wide scope to harness offshore Wind Energy. Given the lead of Europe (especially UK) in offshore wind,the general notion is that offshore wind farms are expensive compared to onshore because of foundation and cable costs. Thanks to Gigantic wind turbines that are now available,US can eliminate the mistakes of Europe in Offshore wind farms and can leapfrog in this field. It is interesting to know countries like China,Korea,Taiwan, France have ambitious plans on Offshore wind energy. Will India follow suit?
Wind Energy Expert
Any efficiency in the range of 20% in solar (thin-film solar photo voltaic (PV) will make solar popular and affordable in developing countries.
Yes. There is excellent scope to harness offshore Wind Energy in US.
Is it an insurmountable problem?
Big is bountiful.
Excellent article. Yes. Solar is expanding at rapid speed in US,Germany etc. Wht ails its impact in developing countries(though the solar insolation is high)) is its low efficiency. Unless efficiency increases,solar PV cannot have much progress in developing countries.