The Technical Investigation Report of Japanese Confluent Type Wind Turbine
Irrigation System Development and Research Project

Background:

A team led by Prof. Yuji Ohya from the Research Institute for Applied Mechanics of Japanese Kyushu University has developed the confluent type small-scale wind generator according to the aerodynamics principle. Its efficiency is 2-3 times greater than the ordinary wind generator. It is very suitable for utilization by the enterprises and the families in the rural areas of the western China. Tsinghua University and Gansu Natural Energy Research Institute (UNIDO International Center for Promotion of Solar Energy Technology and Transfer) proactively contacted the Japanese parties concerned and cooperated with the Research Institute for Applied Mechanics of Kyushu University to jointly undertake the research project of the Japanese NEDO: "The Confluent Type Wind Turbine Irrigation System Development and Research Project". The project is planning to develop and promote the product in the desert area of western China in order to use the local abundant wind power resources for irrigations and improvement of land desertification. In the meantime, the Japanese advanced technology will be introduced and absorbed to produce the wind power generator for application and replication to other developing countries, which have similar conditions as the desert areas in the western region of China.

At the invitation of the Research Institute for Applied Mechanics of Japanese Kyushu University, a group led by Professor Xi Wenhua, director of Gansu Natural Energy Research Institute and UNIDO International Centre Solar Energy Center Technology  Promotion and Transfer visited Japan from 1 - 8 April 2007. The members of the group included Mr. Li Shimin and Mrs. Zhang Lanying, deputy directors of Gansu Natural Energy Research Institute and Professor Song Yaozu from Tsinghua University. During our stay in Japan, we visited Torishima Pump MFG. Co. LTD in Osaka, the Daiichijushi Industry Co., LTD. in Kyuhouji, Yao, Osaka, the 630KWp Demonstration PV Power Station in Gifu-Hashima，Kyushu University and its Research Institute for Applied Mechanics, a large-scale wind farm and the research laboratory of silicon material used in PV application.

Inspection Information:

1. Torishima Pump MFG. Co. LTD in Osaka:

The company is engaged in manufacturing different sizes and types of pumps, turbines and wind turbines with the ability of casting, special metal casting and metal mechanical process. More important, it has a specialized research and development team and testing equipment for the performance of large products. The team not only carries out research on different types of pumps but also has high ability on the R & D of the wind generation turbine.

It is one of manufacturers of Japanese Kyushu University in developing and producing the wind turbine. During the visit, the group met with Mr. Osamu Kimura, (manager), Mr. Hideyuki Morisaki (chief engineer) and other staff of the company. Both parties discussed the details of how to develop wind turbine generator suitable for desert area in western China.

2. Japan Daiichijushi Industry Co., LTD.:

Japan Daiichijushi Industry Co., LTD. is an enterprise specialized in producing plastic products. It is another manufacturer of Japanese Kyushu University in developing and producing the blade of the wind turbine. The company has different types of plastic injection equipments and the ability of making all kinds of molds. It can produce every kind of plastic products with different sizes and different plastic materials. It is worth mentioning that the company has developed a special production process. It is called “Air Aperture Plastic Injection Method”. This process can not only save raw materials by reducing the weight of the blade but also increase the strength and the stiffness of the blade by keeping the curve.

3. 630kWp PV Power Demonstration Station

The PV power station, located in Anpachi-gun Gifu along the new high railway, was built by SANYO Company. The array of the system is supported by 4 pillars. Its appearance looks like a boat or the airplane’s wing. It is 315 meters long and the 37.1 meters high. It consists of 5,046 PV modules (each module is about 125Wp and has the size of 1320x895x35mm and weight of 15Kg). The gross weight is about 3,000 tons and the peak power output reaches 630KW. The total annual power output is 530,000 kWh, which equal to about 3% of the electricity consumption by the local production workshops of the company. The title angle of the array surface is 81 degrees and 20 degrees from south to west.

There are 2 sets of inversions in the system. The DC voltage is 270V and the AC output voltage is 440V. It has been transferred to 6,600V by a transformer to the grid. According to the calculation by the Japanese side, 128,610 liters of petroleum can be saved each year and the annual emission of carbon dioxide will be reduced by 95t-c. SANYO has put the fund generated from the photovoltaic electricity to the “SANYO Ecology Fund” to support environmental protection activities.

As SANYO stresses too much on the advertisement and the outward appearance of the PV Power station, the angle of the pillars is too inclined to obtain the solar energy.

In parallel with the construction of the PV Power Station, SANYO has built parts of the science and technology museum on solar energy and demonstration facilities on the same site. It has achieved a good result to provide the popular science knowledge related to solar energy and optics to the tourists, particularly the students from primary and high school, which we can learn from when we construct the International Solar Energy Center in Lanzhou.

4. Japanese Kyushu University and its Research Institute for Applied Mechanics

Visiting Kyushu University is one of the main purposes of this technical investigation. Kyushu University, a famous comprehensive university, is located in Fukuoka County with a long history of cooperation with some famous Chinese universities, such as Tsinghua University, Xian Communication University and Shanghai Communication University in the aspect of teaching, scientific research and so on. “Confluent Type Wind Turbine Irrigation System Development and Research Project” is just one of project, which Kyushu University is cooperating with Tsinghua University and Gansu Natural Energy Research Institute. Prof. Koterayama Wataru, vice president of the university met the team on the day of our arrival and held warm discussion about the further comprehensive cooperation in the area of renewable energy. Ms. Michiko Ogata, chief of Planning Division, Intellectual Property Management Center of Kyushu University, Ms. Mami Shinozaki, manager for international Affairs and Prof. Yuji Ohya, of Research Institute for Applied Mechanics, Kyushu University also joined the discussion. Afterwards, the team visited the Institute and Earth Aerodynamic Force Laboratory as well as the Wind Tunnel Laboratory and the demonstration wind generator.

The confluent wind turbine is a new type of wind generator developed by the Research Institute for Applied Mechanics of Japanese Kyushu University. On the basis of the original wind turbine and in light of the aerodynamics principle, it designed a wind confluent shell for the turbine, improved the blade structure design and used the new material and so on. Obvious results have been achieved and its efficiency is 2-3 times greater than the ordinary wind generator. The wind generator developed by this institute has various capacities such as 1KW, 2KW, 3KW, 4KW, 5KW and etc. The tower is generally about 10 meters high.

During visit to the Research Institute for Applied Mechanics of Japanese Kyushu University, Prof. Shiro Imawaki, director of the Institute met Prof. Xi Wenhua and his team. Both sides discussed the wind power resources, water resources, and deviation problem between the gross data and the measured data as well as the development of wind power & desert resources, and control of desertification in Wuwei region, Gansu. In addition, both sides decided on the following three items:
(1) To continue to observe the wind data in Wuwei Sand Industry Center and promptly provide the data to the Japanese side.
(2) To provide 10 sets of wind generating unit with single capacity of 5KW as well as water pumps to the Chinese side in September 2007.
(3) To explore the possibility of further cooperation in the research and development area of renewable energy.

The group visited Silicon Material Research Lab of the Institute and held technical talks with Prof. Koichi Kakimoto, officer-in-charge of the laboratory. It is a specialized laboratory mainly engaging in the research of polycrystalline silicon casting thermal load and the interface force between melt silicon and single crystal silicon ingot. The Lab installed 2 sets of X-ray monitor camera on the different angle of silicon furnace. It monitors the whole process of analyzing single crystal growth and polycrystalline cooling, which has high research and equipment level.

During the discussion, Prof. Koichi Kakimoto gave his own viewpoint on the question of which material should be chosen to produce solar cell: polycrystalline or monocrystalline silicon. He pointed out that, although the polycrystalline silicon cell has saved the rowing motion of single crystal in the production process, but it has a high request of raw material purity. The wafer strength, stability as well as cell efficiency are lower than monocrystal.

5. Visit of a Wind Farm

The large-scale wind farm in the south of Aso County was built in the gusty area of a summit. It consists of 10 large-scale wind turbines with the single capacity of 1.5MW. It has generated electricity and been ­­­­­­­­­connected to the grid. The tower is about 40-50 meters high with a 5 meters diameter foundation. The “Asahi” sign was marked on the generator. The wind power resources are relatively stable in that area. When we visited the farm, one unit was being repaired.

Conclusion:

Japan has made great achievements in the application of solar energy, wind energy and other renewable energy. It has also reached the world advanced level in the technologies of semiconductor, electron, casting, metal mechanical processing, and injection molding.

Japan has a good industry foundation and the quality of its personnel is also high. The Japanese products are recognized by the world for its novel design, advanced technology, and excellent processing. All members of the team agreed that the Small-scale Confluent Type Wind Generator is very good in terms of advanced design, excellent workmanship and stable performance. If it can be modified in light of the different local requirements, we believe that the generator is very suitable for application and replication to other developing countries, which have similar conditions as the desert areas in the western region of China.

Through the visit in Japan, we have learnt the current situation of the science and technology development in Japan. We discussed the development and utilization of wind and desert resources as well as solar energy in Wuwei region in Gansu Province. We basically determined the preliminary plan and timetable of the construction of the Wind Turbine Irrigation System and the desert forestation in Wuwei. It was agreed that both sides would further carry out the scientific and technical exchanges and cooperation in the area of solar energy and other renewable energy.