Mannar wind power: Start of large scale grid integration

By Mayura Botejue 

“Glorious history, unique geography and abundant nature ...” – Dr. Rohan Pethiyagoda on the Mannar heritage.

Located strategically to the Northwest of Sri Lanka, Mannar Island is known historically for its famed Adam’s bridge, its natural beauty, land resources and rich culture and history. However one of its recently discovered assets is its abundant wind resources. If a renewable energy dominant electric power supply system is to be attained over the coming decades in Sri Lanka, then a major stepping stone towards this goal is the harnessing of Mannar island’s abundant wind resources.

With energy security a national security issue and responding to climate change concerns a GOSL policy, harnessing the wind resources in the northwestern and northern regions of Sri Lanka will require planning on a visionary scale. 

Further, the prospects for offshore wind development are also promising. Advances in technology and lower costs will lead to construction of large scale wind farms in the sheltered waters of the Gulf of Mannar within the next decade.

Presently, an ADB financed study on Mannar Island has indicated a potential for harnessing 375 MW of wind power capacity. Funding for a 100 MW project to be developed by the Ceylon Electricity Board is in place and construction is to commence shortly. This will be the first phase of the development program in Mannar.

The figure of 375 MW is based on a conservative assessment due to strongly expressed concerns on avian matters and lack of clarity on land use. An informed, scientific approach to the avian question and understanding the land footprint of operational wind farms will clear the way for developing over 400 MW of power capacity on the island. This level of capacity can be developed by utilising 50% of the land available.

Allocation of land on an ad hoc basis for housing, commerce and industry is wasteful and impedes optimal development of the island’s resources. Therefore, an integrated land development plan is essential. It must take into account the requirements and impact of housing, schools, commercial and industrial facilities, tourism, wild life sanctuaries, energy harnessing, agriculture, etc. The environmental impact of these activities on fauna, flora and archaeological heritage sites will require close scrutiny. 

With regard to wind power, land use planners must be aware that turbine arrays at a wind farm are spread over large sections of land. Therefore understanding the land impact of wind farms is essential. For example the actual foot print of the CEB 100 MW Mannar wind project will be less than 3% of the extent of land that the turbines are spread over. The land within the wind farm can be put to multiple uses such as agriculture, animal husbandry, salt manufacture, fish processing, recreational zones, etc. Rules for wind turbine set back from residential, commercial and industrial facilities and sanctuaries will also help to determine land availability for wind farms.

While acknowledging that the ocean front in the Mannar region needs to be stringently policed to prevent fishery poaching, smuggling, etc., the footprint of military bases must be reduced to open up land for harnessing wind and solar energy. 

Mannar Island avian concerns

Resistance to wind power development on Mannar Island continues to be strong with citizens concerned about migratory bird fatalities as a result of collision with wind turbines and the disruption to avian habitats.

This concern is ill-founded. Public expressions on avian matters during the EIA hearings on the CEB 100 MW project indicated lack of knowledge of the modern wind industry with arguments mostly based on erroneous, unscientific and outdated information. 

The following examples are offered to lend credence to the above:

a) Flight path of migratory birds

Belief among avian enthusiasts is that migratory birds use Adam’s Bridge on the western tip of Mannar as a guiding beacon when flying towards the island land mass.

This claim is in variance with the Civil Aviation Authority guideline to pilots on migratory birds. The CAA document reports that migratory birds enter the island from South India via the Jaffna peninsula and then disperse along three directions identified as the North Western route, Eastern route and Central route.

b) Wind turbines scare away migratory birds

This is not a credible statement. Wetland zones abundant with food supply will attract birds even if wind turbines or other structures were in the vicinity. This fact can be verified with ample evidence worldwide. The reader should be aware that the migratory birds that arrive to feed and nest in the Sri Lankan wetlands fly across South India where wind turbines dot the landscape extensively.

The major factor that would deter migratory bird presence in wetlands is water contamination. Avian advocacy groups should pay attention to the water quality of the wetlands and its impact on microorganisms that thrive in the mudflats. These organisms are a vital part of the eco system food chain that water birds thrive on.

c) Wind season and migratory bird season

The SW monsoon induced wind season in Mannar takes place between April and September while the presence of migratory birds is observed between November and March. NE monsoon induced winds are prevalent at the time of migratory bird activity. Potential avian hazards can be addressed by applying set back rules off congregatory zones. Bird flock flights in the vicinity of wind turbines can be detected by radar systems specifically designed for use at wind farms. The detection of a flock leads to automatic shutting down of wind turbines at close proximity to the flight path of birds.

Mannar must emerge from a sleepy backwater that draws the interests of tourists during the 3-4 month winter season to one that is a clean energy hub vital for Sri Lanka to transform from a fossil fuel dominant power system to one that harnesses renewable energy. This would go a long way to reduce the national carbon footprint.

The resources on Mannar Island should be harnessed to its full potential in a responsible fashion to bring economic benefits to the citizens of the region and the nation as a whole.

The youth of Mannar should be educated and trained to be gainfully employed and become the guardians of the island heritage. Employment opportunities will arise at wind farms and related service companies, tourism and research activity related to fauna, flora and archaeology. If properly planned and executed, Mannar Island development activity will be an example to the regions of Sri Lanka where wind and solar resources are prominent and warrant development.

(The writer is Consultant – Renewable Energy.)