Because of their intermittence in generating energy at global level it contributes only with 6 per cent. Clean energy’s share remains small but the benefits prevent construction of more fossil fuel power plants that would emit CO2 for next years.
Power outputs were typically between 100KW and 300KW range for the wind turbines in the early days. Now the modern aerodynamic wind turbines outputs between 1MW to 5 MW. The larger power output needs large area for the turbine and a larger footprint on the ground to locate the utilities and to give access for periodic maintenance.
The major trend in wind turbines has been towards bigger and better turbines. Technologies continue to advance, the emergence of Micro Wind Turbines should add to the availability of clean energy sources especially to the off-grid rural areas in large parts of the developing world.
The rural areas of large parts of Asia, Africa and South America are ill served with grid power. Even where power lines have been laid, there are frequent power interruptions and brownouts. The rural areas, therefore, install and use portable gen-sets burning petroleum fuels to provide back-up power for their needs of lighting and ventilation and for their entertainment and communication needs. These portable gen-sets pollute worse than large fossil power plants and fuel supply in rural areas is as erratic as power supply.
Micro Wind Turbines, are now available for costs of around $6 per watt of output, still expensive but not beyond reach with some government subsidies. Battery storage of power can help tide over dips in power output. The installation and maintenance of Micro wind turbines are not very complex and can be handled by rural mechanics who service farm equipment and water pumps.