By Max Clarke

An independent research study into the phenomenon of shadow flicker from wind turbines was today published by the Department of Energy and Climate Change.

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 issue, along with reports of infrasonic pulses, have been the subject of much debate.
From complaints about distraction and nuisance, to more serious concerns including triggering epilepsy, the phenomenon of shadow flicker has garnered significant opposition to the building of onshore windfarms.

The study, commissioned from Parsons Brinckerhoff following a competitive tender process, found that: 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; and 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.

“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” Said Charles Hendry, Minister of State for Energy and Climate Change:

“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 to ensure that 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:

• The 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; and

• Introduction of sustainability criteria for bioliquids in line with the mandatory requirements introduced by the Renewable Energy Directive.