Press release

Wind turbine shadow flicker study published

This news article was published under the 2010 to 2015 Conservative and Liberal Democrat coalition government

An independent research study into the phenomenon of shadow flicker from wind turbines was today published by DECC. Shadow flicker is the flickering…

An independent research study into the phenomenon of shadow flicker from wind turbines was today published by DECC.

Shadow flicker is the flickering effect caused when rotating wind turbine blades periodically cast shadows through constrained openings such as the windows of neighbouring properties.

The study, commissioned from Parsons Brinckerhoff following a competitive tender process, found:

  • there have not been extensive issues with shadow flicker in the UK
  • the frequency of the flickering caused by the wind turbine rotation is such that it should not cause a significant risk to health
  • in the few cases where problems have arisen, they have been resolved effectively using mitigation measures, in particular turbine shut down systems

The report was peer reviewed by independent experts the Energy Workshop and DECC’s Engineering and Analysis Team. The Department for Communities and Local Government, Defra, and the Department of Health also engaged in the review.

The government has considered the report’s findings and concluded that existing planning guidance on shadow flicker is fit for purpose, and no changes to it are necessary.

Charles Hendry, Minister of State for Energy and Climate Change, said:

“It is vital that we use the most up to date, robust and accurate scientific evidence when looking at the impact of wind farms on communities.

“This study will be helpful to communities, developers and planners as they assess proposals for onshore wind projects.”

In addition, changes to the Renewables Obligation to be debated in Parliament today will help ensure the RO stimulates deployment of new renewable generation to meet our 2020 targets. These changes will come into force on 1 April 2011, and involve:

  • introduction of phased support for offshore wind projects, allowing developers to register groups of turbines in phases
  • introduction of mandatory sustainability standards for biomass. There would be a transition period of mandatory reporting against the criteria from April 2011, with eligibility for ROCs from April 2013
  • introduction of sustainability criteria for bioliquids in line with the mandatory requirements introduced by the Renewable Energy Directive

Notes for editors

  1. The study, by infrastructure company Parsons Brinckerhoff, is available to read in full.

  2. Shadow flicker occurs when a particular combination of conditions coincide in specific locations at particular times of the day and year. For example, it happens when the sun is low in the sky and shines on a building from behind a turbine rotor. When this is viewed through a narrow opening it is known as shadow flicker. Researchers only identified one case of shadow flicker in the UK.

  3. For more information about the changes to the Renewables Obligation, please see the Renewables Obligation consultation.