No. 69: A new wave power generation system to be launched in 2016 (November 19, 2012)

Technology:

Mitsubishi Heavy is developing a new wave power generation system that sets a structure on the sea side of a breakwater. The structure is like a box, and air inside the structure is pushed out when a wave comes into the structure to run a turbine of the generator. Because the structure can bring in waves coming from diagonally, the system has two times higher generation efficiency than the existing system. As a result, the company opened up the road to reduce the generation cost to 40 yen per kW. Although the total power output depends on how many units are built on a breakwater, it is possible to get a generation capacity of 1 mega watt to supply electricity to 200-300 households.

Bridgeand Steel Structure Engineering, a subsidiary of Mitsubishi Heavy, will install a demonstration system in 2014 to start the substantiative experiment using a breakwater in the Tohoku district. The construction cost is about 400 million yen per unit. The system is basically designed for isolated islands where energy cost is rather high. The Japanese government reckons that the introduction of renewable energy in 2012 will increase 12% over the previous year to about 2,500,000 kW on an output basis thanks to the system introduced in July this year to purchase electricity generated by renewable energy at favorable fixed prices for 10-20 years. 

Generation cost, feature, and problem of major renewable energy types

   

Type	Ocean	Photovoltaic	Wind	Geothermal
Generation cost per kW/h	Aiming for less than 40 yen	33.4-38.3 yen (Residence)	9.9-17.3 yen (On land)	9.2-11.6 yen
Feature	Possible to generate throughout the year	Easy to install and operate	Possible to generate regardless of time	Possible to generate throughout the year if hot water is available
Problem	Cost and waterproofing technology	Impossible to generate at night	Generates low-frequency sound	Available places are mostly inside a national park

 

The concept of Mitsubishi Heavy’s wave power generation system

 

The image of Mitsubishi Heavy’s wave power generation system

No. 68: Constructing mega solar plants on the water surface of lakes and ponds (November 17, 2012)

Technology:

West Holdings, one of Japan’s leading solar panel producers, will construct mega solar plants on the water surface of lakes and ponds in alliance with LSIS that is a Korean company specializing in equipment related to power generation. The company will import LSIS’s equipment and float waterproof generation facilities on water surface. It plans to construct 10 mega solar plants with a total generation capacity of 20,000 kW in the initial year. The competition to purchase lands suitable for power generation by renewable energy has been intensifying with the introduction of the system to purchase power generated by renewable energy in July this year, and West Holdings plans to focus on water surface left unutilized.

In the initial stage, the company will construct generation facilities with a generation capacity of 1,000-2,000 kW in the regulation pond of an industrial complex in the Tokyo metropolitan area and in the pond in a park with a water surface area of 118,000 square meters in Osaka. They are scheduled to go into operation next year. The advantage of constructing a mega solar on the water surface is that the temperature of the panels installed on the water surface hardly increases, making it possible to increase output. At the same time, photovoltaic panels shut sunlight to avoid the plague of blue-green algae.  

 

A mega solar plant constructed in an ex-salt field in Shikoku 

by Japan Asia Group 

No. 67: Japanese biogas generation technology goes to Southeast Asia (November 16, 2012)

Business trend:

Kubota will start the biogas generation business in Southeast Asia in alliance with palm oil producers in Malaysia and Indonesia. The company will build plants to generate electricity using methane gas recovered from the effluent and joint companies will sell electricity. Because Malaysia and Indonesia introduced an electricity purchase system, Kubota tries to get orders with the emphasis on its technological advantage. Kubota’s system is called the membrane methane fermentation system. Kubota will sell this system with a generator.

With the help of its original membrane technology, the system can recover methane gas effectively to increase the output by 20%. It is estimated that an average palm oil plant can get a revenue about 130 million yen per year by selling electricity. Kubota already secured an order of 300 million yen for a biogas generation plant from Malaysia for the first time. Malaysia and Indonesia combined have more than 1,000 palm oil producers.  

 

Kubota’s membrane methane fermentation system

No. 66: Present status of ocean current power generation (November 10, 2012)

Technology:

In European Marine Energy Center located offshore of Orkney Islands of Scotland, Kawasaki Heavy plans to conduct substantiative experiments of ocean current power generation in 2014. Kawasaki will install equipment on the seabed 50 meters below the surface of the sea. Propellers 18 meters in diameter each rotate by dint of ocean current to generate electricity, and the direction of propellers will be automatically controlled responding to come and go of the tide. Special treatment will be given to the propellers to avoid malfunction due to adhesion of marine organisms. The company is confident that the technology it has accumulated in posture control and corrosion protection will be of great help to the development of ocean current power generation that offers constant generation.

Japan has the world sixth largest country in terms of the area of territorial waters and excusive economic zone (EEZ). Because it has lots of potential for utilizing ocean energy, the Ministry of the Environment plans to increase the generation capacity of ocean energy to 1,500,000 kW in 2030. Some estimate that Japan’s total wave energy amount to 36 million kW that is equivalent to the generation capacity of more than 30 nuclear power plants. The critical point is how to collect generated electricity.

A research team made up of researchers from the University of Tokyo, IHI, Toshiba, and Mitsui Global Strategic Studies Institute is developing an underwater floating ocean current generator that generates electricity by dint of the black current. Blades 40 meters in diameter each of a generator floating in 50 meters below the surface of the sea level rotate and generate facing the black current. Ken Takagi of the University of Tokyo says “An ocean current always flows to the same direction, allowing for stable generation.”

Mitsui Engineering and Shipbuilding is developing a wave power generator to make the best use of waves that come to and go from Japan of a wide range of frequencies. It will generate electricity by dint of up-and-down motions of small buoys floating on the surface of the sea. The company plans to commercialize the generator toward 2016.  

An image of the tidal wave generator being 

developed by Kawasaki Heavy