How to Tell if a Wind Farm Will Cause Shadow Flicker in Nearby Homes?

Rotating wind turbine blades can cause brightness levels to vary periodically at locations where they obstruct the Sun’s rays. This can result in a nuisance when the shadow is cast over the windows of residential properties. This intermittent shadow is described by the term ‘shadow flicker’ and it can be a cause of annoyance at residences near onshore wind turbines if it occurs for a significant period of time during the year.

Why Nearby Homes Are Assessed for Shadow Flicker

Unmitigated shadow flicker can lead to planning objections, project delays, and reputational risk. 

Shadow flicker assessments determine whether a development could cause significant impacts on surrounding dwellings by modelling expected shadow patterns throughout the year. The assessment identifies which properties may be affected, estimates the duration of any flicker events, and compares results against relevant national or international planning guidelines.

How to Identify if a Dwelling Will Receive Shadow Flicker Effects

There is no statutory guidance or methodology for identifying homes where shadow flicker effects could be caused. In the UK, the industry-established approach is to only consider dwellings that satisfy two conditions:

• Within 130 degrees either side of north of the turbines (as other dwellings outside of this zone generally can’t be affected at UK latitudes); and 
• Within ten rotor diameters of a turbine position (as significant effects are unlikely outside of this range).

Modelling is undertaken for the identified dwellings using specialist shadow flicker modelling software to determine if the wind farm will cause shadow flicker in nearby homes. The model predicts the date and times when shadow flicker is possible at each dwelling. To learn more about how shadow flicker impacts are identified, and can be reduced, you can read our article from earlier this year.

About Pager Power

Pager Power’s industry-standard modelling and almost two decades of wind project experience ensure accurate assessments that give stakeholders confidence and help keep projects on track. 

For more information about what we do, please get in touch.

Image accreditation: Ben Jessop (Dec 2015) fr0m Pexels.com. Last accessed  on 26 August 2026. Available at: https://www.pexels.com/photo/silhouette-of-windmills-on-field-1659688/