Introduction
Windmills, commonly celebrated as a source of renewable energy, are increasingly presenting a new kind of environmental problem. Researchers have found that these installations are inadvertently affecting wildlife in forests, primarily through direct collisions and the emission of high-decibel noise.
Wind Energy in India
Wind energy is essentially the kinetic energy generated by the movement of air. Ideal wind speeds for power generation range between 14 to 16 km/h, enabling turbines to rotate and produce electricity. Accounting for a whopping 70% of all renewable energy installations in India, wind power plays a significant role in the country’s energy scenario. Tamil Nadu proudly holds the title for the largest installed wind capacity, closely followed by Maharashtra, Karnataka, and Rajasthan.
In alignment with the Paris Agreement, India is ambitious about achieving a total installed wind energy capacity of 60 GW by 2022. To achieve this, the nation has introduced the ‘National Offshore Wind Energy Policy’, aiming to harness wind power along its extensive 7,500 km coastline.
Impact on Wildlife
Investigations reveal that there are approximately 50% fewer birds within the areas of windmills in comparison to undisturbed sites. This decline can be largely attributed to two main factors: collisions and noise.
Collisions
Researchers from the Salim Ali Centre for Ornithology and Natural History (SACON) have observed that windmills pose a direct threat to birds and bats in the form of fatal collisions. As a result, these species have started moving towards the forest fringes, leading to potential increases in human-wildlife conflict.
Noise
The noises produced by windmills, reaching up to 85 dB (equivalent to that of large trucks), have also led to wildlife relocations. With the continuous drone of a turbine exceeding 70 dB (compared to 55 dB in urban areas and 75 dB in industrial zones), animals are being driven away from their natural habitats, where the ambient noise is typically less than 40 dB. Such disturbances have triggered a shift in migration patterns for herbivores and their predators, enhancing man-animal conflict especially in regions like Karnataka.
Implications of Windmill Noise Levels
| Location | Noise Level (dB) |
|---|---|
| Windmills | 85 |
| Turbines | 70+ |
| Urban Areas | 55 |
| Industrial Zones | 75 |
| Ambient Forest Noise | <40 |
Mitigating the Effects of Wind Energy on Wildlife
To address these issues, Forests and Wildlife departments have pledged to investigate the impact of windmills on wildlife and establish guidelines to mitigate the effects. This includes enforcing protocols and policy frameworks before allocating forest land for wind farm projects.
Furthermore, project developers are required to gather data through monitoring at existing and proposed wind energy sites. A concerted focus on site selection is needed to minimize fatalities, and in some cases, additional research might be required to tackle bird and bat impact issues.
Salim Ali Centre for Ornithology and Natural History (SACON)
SACON, established in 1990 at Anaikatti, Coimbatore (Tamil Nadu), is a nationally recognized center for information, education, and research in ornithology and natural history in India. Named after Dr. Salim Ali for his lifelong contributions to India’s bird life and conservation efforts, the center conducts comprehensive research covering all facets of biodiversity and natural history.
