2008

<Press Release>
8 April, 2008

Loopwing announces μ2850, 2kW grid-connectable wind turbine

The first grid-connectable Loopwing and a crucial step towards large scale Loopwing

TOKYO (8 April, 2008) - Loopwing Co., Ltd, the innovative researcher and developer of wind turbine and other fluid machineries with the proprietary wing technology, today announced the launch of Loopwing Wind Turbine μ(mju:)2850. μ2850 is available nationwide beginning July 1st.

μ2850 has a diameter of 2.85m and a rated power of 2,000W, which is approximately twice as large in diameter and more than four times as large in capacity as θ1500, which was introduced in 2007. μ2850 is the first Loopwing Wind Turbine that can be connected to a grid and supplies generated power to an office or a factory.

Research and development of μ2850 was conducted jointly by Loopwing Company and International Center for Environmental Technology Transfer (ICETT) with a support from the Ministry of Economy, Trade and Industry(METI) as its Project Promoting Industrial Technologies for Meeting Kyoto Protocol Targets. The concept behind development of μ2850 was 'to achieve high safety, durability, practicality, and low noisiness, and thereby to overcome problems faced by the conventional propeller'; the same concept for θ1500. Three tests were conducted at gusty areas of northern Japan to examine the basic performance and a demonstration model was installed in Nakagami County in Okinawa Prefecture and has been operating to supply power to a local office. The demonstration shows that μ2850 starts rotating at a wind speed of approximately 3m/s and starts feeding power to a grid through an inverter at approximately 4m/s. μ2850 is planned to be installed at sites of corporations and local governments in Japan as well as in overseas. Loopwing Company is expecting large orders of the model in the future and looking to expand its manufacturing and distribution capacity.

Upon the announcement today, Minoru Yoshida, Representative Director of Loopwing Company said "there has been very few small wind turbine products in the market which actually feed power to a grid, rather than consume it, and simply do the job. Our μ2850 has great advantages over those conventional products not just in practicality but also in safety, durability and low noisiness. This model has drawn a great deal of attention from the wind industry, and we expect that it delivers an innovation and leads the market to expand."

As its first-grid connectable wind turbine, μ2850 is a significant model for Loopwing Company, and it at the same time marks a meaningful step towards a large scale Loopwing Wind Turbine. Made from thin metal plate, blade of Loopwing Wind Turbine can be made lighter, stronger and larger than conventional propeller blades. Blade formation process of μ2850 employs specially designed pressing and riveting methods, without using a mold. Establishment of this formation process has opened a door for Loopwing Wind Turbine to large-scale expansion and cost-effective manufacturing. In fact, Loopwing Company has recently started development of two larger models of 5kW and 11kW with diameters of 4.8m and 6.7m respectively, and the company is looking to develop a 10MW model with a diameter of 168m sometime in the future. The formation process has also given a realistic possibility for Loopwing technology to be applied for fluid machineries other than wind turbine, such as turbines for tidal power generation and small scale hydro power. Loopwing Company will accelerate its innovative R&D activities to deliver new values in the fields of energy generation.


Product Outline : Loopwing Wind Turbine μ2850

1. Mechanism

Blade

• The blade of Loopwing Wind Turbine has no pointed tip to create a vortex; the main cause of turbine noise ('tip vortex free mechanism'). Test results conducted at gusty parts of Japan confirmed low-nosiness of μ2850 at an equal level to that of θ1500.
• Loopwing blade has a structure of the truss with both ends and a tip of each blade supported against two others. As proven in structural mechanics applied to bridge engineering, the truss structure has high durability. The main shaft is also supported at both ends which further improves durability and tolerance to vibration of the turbine.
• The blade of μ2850 is cut out from a thin aluminum alloy plate using CNC(Computer Numerical Control) to which camber is added by pressing.

Revolution increase, Power generation, Body

• Revolution of the rotor is increased by 9 times through timing belts in a rear housing and then transferred to a generator unit in a nacelle at a lower part of the turbine.
• Nacelle is usually located at the same height as a main shaft of a turbine rotor whereas the nacelle of μ2850 is located at a lower part of the turbine, directly above a pole, which stabilizes the turbine by keeping the gravity low and at center. This enables the over-200kg turbine to change directions with a mere 10W yaw control motor which contributes to decreasing power required for control.
• μ2850 system includes a specially customized inverter that transforms generated DC power into grid-connectable AC.
  

Start and Cut-out

• An anemometer is installed underneath the turbine to detect a starting wind speed, and a yaw control system deflects the turbine to face the wind and start rotation. The turbine starts rotation with a natural wind at approximately 3m/s without consuming power and starts feeding power to a grid at approximately 4m/s.
• When the anemometer detects a cut-out wind speed (14m/s at standard setting), the yaw control deflects the turbine side to the wind and stops rotation by letting gusts go through. μ2850 is equipped with an electromagnetic braking system, another electrical fail-safe to avoid over-speeding.
• Battery for the yaw control is charged by a small PV panel, which makes it possible for the whole control system to function even during power outages. PV power also stabilizes overall output into a grid.

2. Specifications and Data

Average wind speed = approx. 3.5m/s. Maximum wind speed = 7m/s. Results shows that uu2850 starts at approx. 3m/s, and the generated voltage reaches 100V and starts outputting AC power at approx. 4m/s. When the wind speed becomes below 4m/s, the turbine stops outputting power, and the voltage becomes 0. However, swiftly reacting to the wind speed rising back, the turbine re-starts outputting AC power. Most of the conventional propeller turbines consume power each time it restarts and are not able to react to frequent changes in wind speeds.