Wind Energy

What is Wind Energy?

The Solar energy is the indirect source of energy for moving air is called wind. About 2% of the sunlight striking the earth is converted into the kinetic energy of moving air. Wind Energy is a Renewal Source of Energy (Non-conventional Energy).

The uneven absorption of the solar radiation by the earth’s surface causes differences of temperature, density and pressure which produce air movements at local, regional and global levels powered by wind energy.

Wind energy is the kinetic energy associated with the movement of atmospheric air. Wind turbines transform the wind energy into mechanical energy, further converting to electric energy to generate electricity.

Five nations – Germany, USA, Denmark, Spain and India – account for 80% of the world’s installed wind energy capacity.

India rank 4th in the world with a total wind power capacity if 1080 MW out of which 1025 MW have been established in commercial projects.

Evolution:

• As early as 4000 - 3500 BC, the first sailing ship and wind mills were developed by harnessing wind energy.
• The wind has been used to power ships, grind grains, pump water for irrigation and do other types of work.
• In present times the greatest potential for using wind is for the production of electricity.
• Wind turbines, like wind mills are mounted on a tower to capture the most of the wind energy. Wind mills can be used to drive generators to producing electricity.
• Wind turbines can be used single or in clusters. When wind turbines occur in clusters they are called ‘wind farms’. A wind farm can be located onshore and offshore.

 

How much electricity a turbine can produce?

There are three main variables determine the production of electricity:

1. Wind Speed- stronger winds produce more energy. Wind turbine generates energy at a speed of 4-25 metres per second.
2. Blade Radius- the larger the radius of blades, the more the energy produced. Doubling the blade radius can result in four times more power.
3. Air Density- Heavier air exerts more lift on a rotor. Air density is a function of altitude, temperature and pressure. High altitude locations have low air pressure and lighter air so they are less productive turbine locations. The dense heavy air near sea level drives rotors faster and thus relatively more effectively.
 

Two Types of Wind Turbine:

1. Horizontal-axis design has two or three blades that spin upwind of the tower. A horizontal axis machine has its blades rotating on an axis parallel to the ground.

2. Vertical-axis turbines has vertical blades that rotate in and out of the wind. The vertical axis turbine has its blades rotating on an axis perpendicular to the ground. This drag-type turbine turns relatively slowly but yields a high torque. It is useful for grinding grain, pumping water and many other tasks, but its slow rotational speeds are not optimal for generating electricity. Vertical- axis turbines do not take advantage of the higher wind speeds at higher elevations (100 feet and so) above the ground vis-a-vis horizontal axis turbines.
 

Potential of Wind Energy in India:

India’s wind power potential at hub height of 120 meters is 695 GW.
The wind power installed capacity has grown by 1.8 times during past 6.5 years to about 38.26 GW (as on 31st October 2020) and India now has the 4th largest wind power capacity in the world.
The wind energy sector is led by the indigenous wind power industry with a strong project ecosystem, operation capabilities and a manufacturing base of about 10 GW per annum.
Ministry is developing strategy and roadmap to harness the potential of offshore wind energy along India’s coastline.
The National Institute of Wind Energy (NIWE) has recently launched Wind Energy Resource Map of India at 100 meter above ground level (AGL) on online Geographic Information System platform.

Gujarat has the leading potential followed by Karnataka, Maharashtra, Andra Pradesh according to the resource map.

Capacity installed:
• Tamil Nadu – 7200 MW
• Maharastra – 4000 MW
• Karnataka – 2700 MW
• Rajasthan – 2700 MW
Andra Pradesh, Madhya Pradesh, Kerala are minor players with installed capacity of less than 1000 MW.
 

Government Policy for Wind Energy:

National Offshore Wind Energy Policy, 2015:

Under this Policy, the Ministry of New & Renewable Energy (MNRE) has been authorized as the Nodal Ministry for use of offshore areas within the Exclusive Economic Zone (EEZ) of the country and the National Institute of Wind Energy (NIWE) has been authorized as the Nodal Agency for development of offshore wind energy in the country and to carry out allocation of offshore wind energy blocks, coordination and allied functions with related ministries and agencies. It would pave the way for offshore wind energy development including, setting up of offshore wind power projects and research and development activities, in waters, in or adjacent to the country, up to the seaward distance of 200 Nautical Miles (EEZ of the country) from the base line.
 

Scheme for Procurement of blended Wind power from 2500 MW ISTS connected Projects:

The objective of the Scheme is to provide a framework for procurement of electricity from 2500 MW ISTS Grid Connected Wind Power Projects with up to 20% blending with Solar PV Power through a transparent process of bidding. Solar Energy Corporation of India Ltd. (SECI) is the nodal agency for implementation of the Scheme.
It has provisions for payment security mechanism, commission schedule, power offtake constraints, power purchase agreement, etc. SECI has awarded 970 MW of projects under this scheme at discovered tariff of Rs. 2.99-3.00 per unit.

Guidelines for Tariff Based Competitive Bidding Process for procurement of power from Grid Connected Wind Solar Hybrid Projects:

The objective is to provide a framework for procurement of electricity from ISTS Grid Connected Wind-Solar Hybrid Power Projects through a transparent process of bidding.
Individual minimum size of project allowed is 50 MW at one site and a single bidder cannot bid for less than 50 MW. The rated power capacity of one resource (wind or solar) shall be at least 33% of the total contracted capacity.
It has provisions for payment security mechanism, commission schedule, power offtake constraints, power purchase agreement, etc. SECI is the nodal agency for implementation of the Scheme.
 

Also Read: Solar Energy

Source: PIB