A wind turbine is a device that converts the wind's kinetic energy into electrical power. Wind turbines are manufactured in a wide range of vertical and horizontal axis types. Larger turbines can be used for making contributions to a domestic power supply while selling unused power back to the utility supplier via the electrical grid. Arrays of large turbines, known as wind farms, are becoming an increasingly important source of intermittent renewable energy and are used by many countries as part of a strategy to reduce their reliance on fossil fuels.
HAWT Wind Adjustments
Horizontal-axis wind turbines (HAWT) have the main rotor shaft and electrical generator at the top of a tower, and must be pointed into the wind. Large turbines generally use a wind sensor coupled with a servo motor. Most have a gearbox, which turns the slow rotation of the blades into a quicker rotation that is more suitable to drive an electrical generator.
The constant mechanical adjustments to wind direction results in extreme loads and eventual material fatigue and gear box failures. As such, HAWT typically require constant maintenance and replacement of gear box every 2 years.
All turbines are equipped with protective features to avoid damage at high wind speeds, by feathering the blades into the wind which ceases their rotation, supplemented by brakes.
The size and height of turbines increase year by year. Offshore wind turbines are built up to 8MW today and have a blade length up to 80m. Usual tubular steel towers of multi megawatt turbines have a height of 70 m to 120 m and in extremes up to 160 m.
The blades rotate at 10 to 22 revolutions per minute. At 22 rotations per minute the tip speed exceeds 90 meters per second (300 ft/s). Higher tip speeds means more noise and blade erosion.
HAWT excessive tower height also significantly impacts operational maintenance cost.
HAWT also have a negative impact on the natural environment due to untended bird strikes.
Veritical Axis Wind Turbine
Vertical-axis wind turbines (or VAWTs) have the main rotor shaft arranged vertically. One advantage of this arrangement is that the turbine does not need to be pointed into the wind to be effective, which is an advantage where the wind direction is highly variable. It is also an advantage when the turbine is integrated into a building.
Also, the generator and gearbox can be placed near the ground, using a direct drive from the rotor assembly to the ground-based gearbox, improving accessibility for maintenance.
Since the VAWT automatically adjust to wind from any direction, the average power output is 20-30% higher as compared to a HAWT.
GEI GLOBAL VAWT SOLUTION
Major drawbacks for early VAWT designs (Savonius, Darrieus and giromill) included the significant torque variation or "ripple" during each revolution, and the large bending moments on the blades, although lower rotational speed.
GEI GLOBAL ENERGY CORP by integrating our strong Mechanical Engineering design skills and tools with extensive NASA design and operational data, Finite Element Structural Modal Analysis, and Computational Fluid Dynamics resolved all past VAWT flow induced structural dynamics concerns.
GEI GLOBAL VAWT have no guide wires and through design MODAL and fatigue analysis have resolved ALL blade vibrational concerns with greater torque.
GEI GLOBAL VAWT have NO GEAR BOX due to a Variable Frequency Direct Drive Transmission. The result is a 30 year design life, a 100+ MPH wind speed survivability, with a 15 minute annual maintenance schedule.
World Wind Distribution
In 2015 China represented 34.03% of all countries for wind turbine power generation.
China's 2050 national plan for wind energy development is 17% of the total electricity or 1000 GW.
The China wind energy rejection rate reaches 47% in the first half year of 2016 and is currently the biggest barrier for the further development of wind energy.
The wind energy rejection is caused by CHINA HAWT excessive maintenance, wind power fluctuations and availability not matching required power needs, and time necessity for wind turbine electric grid construction to interface with central grid.
The GEI GLOBAL CHINA WIND TURBINE SOLUTION includes our HYBRID VAWT infrastructure with integrated advanced energy storage systems within the base.
Higher power output
Constant power output with improved match between available power and required power.
Ability to locate "DISTRIBUTED WIND FARMS" closer to local communities with excess power only sent back to central grid.
Also doubles as remote self-powered Telecommunication Towers.
Less Noise and acceptable to environmentalist due to no bird strikes.