This research examines the flow velocity characters around lift-based straight-wing vertical-axis wind turbines (SW-VAWT) by numerical simulation. The precision of the prediction technique was confirmed. Furthermore, we estimate the flow behaviour during the wind turbine rotation by using this numerical simulation technique, and evaluate the flow around the SW-VAWT. This paper presents an outline of the work and gives the results of the calculations.

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The tidal and sea current turbines are one of potential utilization of renewable energies as well as offshore wind ones. However they possibly produce efficiently electricity because of high density of water to air and more steadiness of flow to winds, hydro turbine generation system is less employed than wind one. We are studying an application of Straight Wing Vertical Axis Hydro Turbine Generation Systems in the tidal current. This paper presents the results of hydraulic model test using 2-dimensional channel and field test.

SUMMARYIn the current wind turbine generation system, there are substantial problems such as the fact that the maximum power of the wind turbine cannot be obtained in the presence of fluctuating wind speed, as well as high cost and low annual net electricity production (due to mismatch between generators and wind turbines). A new wind turbine generator optimized for the wind turbine output is presented in order to solve such problems. This wind turbine generator consists of a permanent magnet generator, a reactor, and a rectifier, and uses neither a control circuit which requires standby electricity nor a PWM converter having a switching element. By selecting the most appropriate combination of a permanent magnet generator with multiple windings and a reactor connected in series with each winding, the maximum output of the wind turbine can be obtained without using a control circuit. The new wind turbine generator was directly coupled with a straight-wing nonarticulated vertical-axis wind turbine (SW-VAWT), and matching of the generator with the wind turbine was examined in field tests. The test results and review confirm that the new wind turbine generator is highly matched with the wind turbine in the presence of fluctuating wind speed.

This paper reports the results of technical and economic feasibility studies of floating offshore wind farms under typical environmental conditions in Japanese Waters. Outline designs are considered, with economic assessments. Both horizontal and vertical axis wind turbines are considered, although it is realised that horizontal axis machines now dominate.