Shadow Flicker Assessment
What is this assessment?
A Shadow Flicker Assessment is a crucial process for evaluating the potential impacts of wind turbines on nearby residential areas. It is specific to onshore wind projects only.
The Shadow Flicker Assessment findings are submitted as part of the project Planning Application.
Guidance on conducting a Shadow Flicker Assessment can be found in the Wind Energy Guidelines (2006), and the draft revised Wind Energy Guidelines (2019) - Section 5.8.
Legal basis: Planning and Development Act 2000.
What should it include?
Below shows the steps to completing a Shadow Flicker Assessment.
Define the study area
Identify a defined study area around the wind farm site. It typically includes all residences within a certain distance from the turbines.
Identify receptors
Map out all potential receptors (houses, schools) that may be affected by shadow flicker.
Collect data
Gather data on turbine specifications, including height, rotor diameter and location.
Analyse geographical features and landscape to understand how they may influence shadow flicker.
Model shadow flicker
Use software models to simulate the shadow flicker effects based on turbine operation schedules, sun position and local topography. Calculate the number of hours per year that shadow flicker may occur at each receptor.
Impact assessment
Evaluate whether the predicted shadow flicker hours exceed acceptable thresholds established by regulations or guidelines. Consider factors such as duration and frequency of flicker events.
Mitigation measures
If significant effects are identified, propose mitigation strategies such as turbine layout adjustments or operational restrictions during sensitive periods.
Reporting
Document findings in an Environmental Impact Assessment (EIA) report. This should include detailed analysis and recommendations for managing shadow flicker impacts.
Submitting your assessment
The results of this assessment should be included with your submission to the relevant planning authority.