Wind Energy Expansion Raises Concerns for Bats: India Faces a New Test in Balancing Clean Power and Wildlife Protection

Scientists call for pre-construction surveys, long-term monitoring and risk-based turbine operations as concerns grow over bat fatalities at wind farms and gaps in India’s ecological data.

(SDNA) New Delhi: As India accelerates its transition towards cleaner energy, wind power is becoming an increasingly important part of the country’s energy strategy. Yet, alongside its environmental benefits, the rapid expansion of wind farms is raising questions about the impact of renewable energy infrastructure on wildlife, particularly bats.

The fast-moving blades of wind turbines can pose a serious threat to bats, with collisions and pressure changes around operating turbines linked to fatalities in several parts of the world. In India, however, the overall scale of the problem remains unclear. Scientific information about the number of bats killed, the species most affected and the seasonal patterns of these deaths is still limited.

Wildlife researchers argue that slowing the clean-energy transition is not the answer. Instead, India needs stronger ecological assessments, better monitoring systems and practical measures to reduce wildlife risks while allowing renewable energy projects to operate efficiently.

India’s Rich Bat Diversity, but Limited Scientific Data

India is home to approximately 135 bat species, around 16 of which are reported to be endemic to the country. These mammals perform essential ecological functions. Insect-eating bats help regulate insect populations, while fruit-eating species contribute to seed dispersal and forest regeneration.

Despite their ecological importance, the effects of wind energy development on Indian bat populations remain insufficiently documented.

Researcher Rohit Chakravarty has highlighted three key questions that need to be addressed: which species are most vulnerable to turbine-related fatalities, how frequently these deaths occur, and whether mortality rates vary across seasons.

The State of Indian Bats report has also identified wind turbines as a potential threat to bats. Other pressures recognised internationally include deforestation, agricultural expansion, urbanisation, hunting and climate change.

Without reliable baseline information, conservation authorities may struggle to identify high-risk locations or determine which mitigation measures are most effective under Indian conditions.

Why Are Bats Flying Near Wind Turbines?

Scientists have not yet established a single explanation for why bats approach wind turbines or why collisions occur more frequently under certain conditions. Several possible explanations are being investigated.

Winifred Frick, chief scientist at Bat Conservation International, has noted that some bats may be attracted to unfamiliar structures, while artificial lighting may also influence their movements in certain situations.

Another possibility is that insects gathering around turbines attract bats looking for food. While pursuing prey, bats may enter the area swept by the rotating blades and face a risk of collision.

Although bats use echolocation to navigate and locate prey, this ability does not eliminate every danger associated with rapidly moving turbine blades. Researchers are also investigating the role of pressure changes around blades, which can cause fatal internal injuries in bats without direct physical contact. This phenomenon is known as barotrauma.

However, the relative importance of these factors can vary, and further research is needed to understand the mechanisms behind bat fatalities in different environments.

Evidence of Bat Fatalities Has Emerged in India

Research conducted around wind energy installations in different parts of India has documented bat carcasses, raising concerns about the possible effects on local populations.

A 2025 study reportedly recorded eight bat carcasses in a wind energy area in the Thar Desert.

Researchers have also investigated the issue in Satara district of Maharashtra and the Kanyakumari region of Tamil Nadu. Rohit Chakravarty and his colleagues have documented evidence of turbine-related fatalities involving species such as the Greater Yellow House Bat, Lesser Yellow House Bat and Fulvous Fruit Bat.

These observations suggest that bats capable of flying at moderate or considerable heights may encounter turbine blades under certain conditions. However, the discovery of carcasses at individual sites does not, by itself, establish the full scale of mortality across India’s wind energy sector.

Southern India deserves particular attention because of its bat diversity and the range of natural and human-made structures that provide roosting opportunities. In places such as Kanyakumari, bats may use temples, houses, rocky formations and natural habitats for shelter. Wind energy planning in such landscapes needs to account for local ecological conditions rather than relying on uniform assumptions.

Migratory Bats May Face Additional Risks

Some bat species travel considerable distances in response to seasonal changes, but their migration routes and movement patterns remain less understood than those of many bird species.

This lack of information makes it difficult to predict when and where bats may encounter wind turbines.

International research has identified periods of increased collision risk for certain migratory bat species during autumn, when seasonal movements and other biological activities can bring them into areas containing wind farms. These findings, however, cannot automatically be applied to every Indian species or region.

In India, more research is needed to map seasonal bat movements and identify important migration corridors. Chakravarty has suggested that winter monitoring in states such as Rajasthan and Gujarat could help researchers better understand the movements of species including tomb bats.

Climate, vegetation, topography and species composition vary significantly across the country. Consequently, mitigation measures that work in one region may not produce the same results elsewhere.

Counting Dead Bats Is a Scientific Challenge

Estimating the actual number of bats killed at a wind farm is more complicated than simply counting the carcasses found beneath turbines.

Researchers must systematically search large areas around turbines and, in some cases, along access roads. Even then, many carcasses may go undetected.

During a 2024 study in Satara, Maharashtra, researchers searched around turbines and on nearby roads for bat remains. However, conducting repeated searches across a large installation containing approximately 1,000 turbines was difficult with a limited research team.

Finding only one carcass during a survey does not necessarily mean that only one bat died. Small carcasses can disappear into grass and shrubs, while scavengers may remove them and natural decomposition can make them difficult to detect. Seasonal vegetation growth and rainfall can further complicate searches.

These factors can lead to substantial underestimation of actual mortality if researchers rely solely on the number of carcasses recovered.

Experts therefore recommend systematic monitoring from the early stages of a wind farm’s operation. Repeated surveys, combined with methods to account for carcass removal and searcher detection rates, can provide more reliable estimates and help identify changes in risk over time.

Legal Protection and Environmental Assessment Need Attention

The regulatory framework is another important part of the conservation debate.

According to the information cited in the discussion, only six bat species receive the highest level of protection under Schedule I of India’s Wild Life (Protection) Act, as amended in 2022. These include Wroughton’s Free-tailed Bat and Salim Ali’s Fruit Bat.

Conservationists have called for clearer guidance on how risks to bats should be evaluated and addressed during wind energy development, including for species that do not receive the highest category of legal protection.

Wildlife expert Soumabh Bhattacharya has highlighted that general provisions relating to protected areas and environmentally sensitive zones can help safeguard wildlife, but measures specifically addressing bat-related risks remain limited.

Environmental impact assessment requirements also warrant attention. Not every renewable energy project in India is necessarily subject to the same level of detailed environmental assessment. This makes it important to identify potential risks to bats early in the planning process, particularly in ecologically sensitive landscapes.

Environmental and social safeguards applied by some international lenders can provide an additional layer of scrutiny by requiring assessments of ecological sensitivity and project-related impacts. Stronger, consistent assessment practices could help ensure that wildlife considerations are incorporated before construction begins.

Curtailing Turbine Operations Could Reduce Fatalities

One potential mitigation measure is known as curtailment—temporarily restricting or stopping turbine operations during periods when bats are considered to be at higher risk.

Depending on local conditions, operating decisions may take account of wind speed, weather patterns, seasonality and observed bat activity. One approach is to increase a turbine’s cut-in speed, the minimum wind speed at which it begins generating electricity. Under suitable conditions, this can reduce the time blades operate at lower wind speeds, when some bat species may be particularly active.

However, strategies developed and tested overseas need to be evaluated under Indian conditions before their effectiveness can be assumed. Collaboration between researchers and wind energy companies would help compare different operating practices and identify approaches that reduce wildlife fatalities while managing energy losses.

Other proposed interventions include acoustic deterrents intended to discourage bats from approaching turbines. Their effectiveness can vary by species and setting, and they should not be treated as a universal solution. Acoustic monitoring systems may also help detect bat activity and support more targeted operating decisions.

Conservation Planning Must Begin Before Construction

Rajesh Puttaswamy, a citizen scientist and trustee associated with the Bat Conservation India Trust, has emphasised the importance of incorporating wildlife protection into project planning from the outset rather than responding only after turbines become operational.

A comprehensive pre-construction assessment could include:

• Species identification: Documenting bat species present in and around the proposed project area.
• Roost mapping: Recording important shelters in trees, caves, wells, buildings and rocky structures.
• Seasonal monitoring: Identifying periods important for migration, feeding and reproduction.
• Risk assessment: Evaluating the potential influence of turbine height, design, location and operating conditions on bat activity.
• Long-term follow-up: Continuing systematic monitoring after construction to identify emerging risks and measure the effectiveness of mitigation measures.

Pre-construction surveys alone are not enough. Bat movements and habitat use can change over time, and new roosting sites or activity patterns may emerge. Continuous monitoring and adaptive management are therefore essential to keep conservation measures effective throughout a project’s operational life.

Clean Energy and Biodiversity Must Advance Together

For India, expanding wind power is an important step towards improving energy security and reducing carbon emissions. But the environmental value of renewable energy projects also depends on how carefully their wider ecological impacts are managed.

Better scientific data, region-specific conservation plans, clearer regulatory guidance and active participation by energy companies can help reduce risks to bats. Researchers also need sustained support to establish reliable mortality estimates, identify vulnerable species and test practical mitigation measures.

The challenge is not to choose between renewable energy and wildlife conservation. It is to design and operate renewable energy infrastructure responsibly, using evidence to avoid or minimise harm wherever possible.

A genuinely green energy transition must protect more than the climate: it must also safeguard the biodiversity that sustains healthy ecosystems. By integrating wildlife considerations into wind farm planning, operation and long-term monitoring, India can work towards a cleaner energy future that is more compatible with nature.

(SDNA) — News Behind the Truth