Japan Looking at Offshore Wind Turbines

Offshore Windfarm for Land of the Rising SunDid you know that Japan is the third-largest consumer of oil? Japan is also the fifth-largest contributor to carbon emissions. In an attempt to reduce the national need for oil and to cut back on carbon emissions, Japan is looking to wind power as a solution. But Japan is not a largely connected country nor does it have a whole lot of room to spare for turbines, so Japan is starting to emulate Europe and is looking offshore for sites to build wind turbines.

Now, unless you have been living in a cave (and off the grid) for the last fifteen or so years, you may have heard of a little international agreement called the Kyoto Protocol. Well, Kyoto is in Japan, so if Japan cannot change its ways in order to comply with Kyoto-imposed emissions limits, that is not exactly a resounding confirmation that carbon emissions can or should be cut by anyone else. According to a Reuters story, as of March 2007, Japan was still over its "Kyoto" limit by 13 percent. So Japan is looking to wind power to help out.

Japan hopes that wind power will provide around 0.2 percent of the country's primary energy supply by March 2011. That figure might rise dramatically if major electric companies follow through with plans to build offshore wind farms near coastal power stations. -- Reuters

Offshore Windfarm

Gee, that 0.2 percent is pretty dismal, isn't it? Allow me to contextualize that number for you. The US only gets 1 percent of its power from wind. The European Union (on average) is at about 3 percent. If you read that last link's full story, you will see that the world seems to be just starting to embrace wind power as a viable option to cut back on fossil fuel consumption and cut back on those pesky greenhouse gases as well. Although I would be remiss if I did not point out at this moment that similar "wind power as the next big thing" articles have been published from time to time over the last fifteen years. However, this US News and World Report article adds a sobering picture of exactly how many wind turbines will need to be built to produce a significant percentage of energy needs.

No renewable energy is growing faster than wind power, and yet those gigantic white turbines—one built every four hours—are churning out less than 1 percent of the nation's electricity. To get to 20 percent—President Bush's aim—production would have to ramp up to one every 15 minutes for 25 years, says Vic Abate, vice president for renewables at General Electric. -- US New and World Reports

Power Curve of Wind TurbinesYes, that refers to the USA, but I think that the quote does a fine job of showing us that wind power will have to really step up its game if it is going to make a dent in our over-consumptive ways. Thus the need for Japan to look offshore. Europe has already started building turbines out at sea in order to reap the benefits and electrical generation capacity from more consistent winds at higher speeds. You see, wind power is produced more efficiently when the wind is around 14 miles per hour (mph) or 6.5 meters per sec (m/s). The generation of electricity needs at least 3 m/s just to get the turbine started. The wind on the ocean or sea is usually not only at a higher speed than on land (in general), but also more consistent. As soon as two years ago, Japan was having some problems getting utilities to buy into wind power as the power can be rather unstable or inconsistent. The biggest issue with wind power in Japan is that the electricity grid is not totally connected.

“Continental European countries such as Germany and Denmark can transfer excess power from windmills to other countries,” said Arakawa. “The electricity networks of Japan’s 10 utilities aren’t connected like those in Europe. That’s the reason why it’s difficult to install windmills in Japan.” To ensure steady supply, Tohoku Electric Power Co., Japan’s fourth-biggest generator, in March started requiring owners of new windmills to store energy in batteries before distribution rather than send the electricity direct to the utility, said spokesman Satoshi Arakawa. -- Bloomberg via Alternative Energy News

Offshore Windfarm Setup 

The placement of wind turbines offshore has its own set of advantages and disadvantages. For starters, it is more costly to build the turbines at sea rather than on land. "In Europe it costs about 50 to 100 percent more to build offshore wind farms to those based on land. In Japan, it could cost even more as the island nation is surrounded by deeper seas"(Reuters). But as Denmark is finding out, the turbulence at sea is less than that on land, which translates to less wear on the turbine and a longer life span for the equipment.

The wind at sea is generally less turbulent than on land. Wind turbines located at sea may therefore be expected to have a longer lifetime than land based turbines. The low turbulence at sea is primarily due to the fact that temperature variations between different altitudes in the atmosphere above the sea are smaller than above land. Sunlight will penetrate several metres below the sea surface, whereas on land the radiation from the sun only heats the uppermost layer of the soil, which thus becomes much warmer. Consequently the temperature difference between the surface and the air will be smaller above sea than above land. This is the reason for lower turbulence. -- Danish Wind Industry Association

Of course, maintenance at sea may or may not be more costly, depending on the particular site, but building turbines offshore would also negate the issue of turbine noise disrupting neighbors. There is also the issue of marine life, namely birds. European wind farms are showing mixed results on this. From February 2007, infrared cameras at Danish wind farms are indicating that birds are avoiding the giant turbines, but other sites are suffering from bad choices in site planning to ensure the safety of local large bird populations. For more reading on the bird + wind turbine = death debate, check this site out. It's a little over-the-top on the conspiracy angle, but does have lots of good links to studies. Japan is not rushing into anything. Although preliminary reports show that there may be better wind power potential at sea than on land in the island country, Japan is only "set to study the feasibility of offshore wind energy this year. One option might be to follow the example of Scotland, which installed offshore turbines in deep water in 2006. (Reuters) Further Reading:

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  • Posted on Jan. 23, 2008. Listed in:

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