Policy brief for Sri Lankan Govt.: Call to re-evaluate wind energy strategies for sustainable future

Sri Lanka’s pursuit of clean energy is vital, but its current enthusiasm for large-scale wind farms warrants immediate and critical reassessment. Scientific evidence, coupled with Sri Lanka’s unique national context, indicates that wind energy may not be the optimal solution for achieving long-term energy security and sustainable development. Continuing down this path risks misallocating resources, hindering genuine progress, and potentially causing irreversible environmental and socio-economic harm as follows.

- By Hiran Daluwatta

The inevitable constraint of inconsistent and weak winds

The viability of wind energy depends heavily on the consistency and intensity of wind speeds. According to the Sri Lanka Sustainable Energy Authority (SLSEA) and multiple wind resource assessments conducted in collaboration with institutions like the National Renewable Energy Laboratory (NREL, USA) most regions in Sri Lanka exhibit only marginally viable wind speeds.

Wind power generation is most efficient when wind speeds are between 6.5 and 9 meters per second (m/s) at a turbine hub height of 80-100 meters. In Sri Lanka, with the exception of narrow coastal belts such as Mannar, Puttalam, and parts of Hambantota, the average wind speeds fall below this optimal threshold. Even in the most promising zones, average wind speeds fluctuate significantly on a seasonal basis, primarily due to the bi-monsoonal climate and complex terrain. This temporal and spatial variability results in poor capacity factors — a key performance metric in wind energy. For instance, while wind arms in Denmark or Texas achieve capacity factors of 35-45%, Sri Lankan wind farm often perform at 30-25%, leading to low efficiency and questionable returns on investment.

The looming uncertainty of monsoons and climate change

Sri Lanka’s location in the Inter-Tropical Convergence Zone (ITCZ) brings intense seasonal monsoonal shifts, causing highly variable wind patterns. This, in speed and direction, making forecasting and grid planning exceptionally difficult.