At-property shadow flicker monitoring

Shadow flicker is nothing new – flicker mitigation technology has been around for years. But issues persist and they are very difficult to investigate. Making use of advances in IoT technology Visualwind are helping eliminate flicker with at-property monitoring.

Shadow flicker – the effect caused inside a property when a wind turbine sits between it and the sun – is subject to planning guidance that requires wind farm developers to assess and mitigate shadow flicker impacts at properties in the vicinity of their developments.

During the development stage, software is used to identify the turbines that will cause flicker and the properties that will be subject to it. During the construction stage, wind turbines that are predicted to cause shadow flicker are typically fitted with mitigation technology that stops the turbine at certain times of year and day if the weather conditions are such that flicker would occur.

Doesn’t mitigation technology remove shadow flicker as an issue?

In theory, this use of software and mitigation technology means that flicker can be eliminated as an issue. However, in practice, complains about flicker continue to occur and wind turbines with mitigation technology continue to cause shadow flicker. The reasons for this are numerous and complex. Human error in setting up mitigation systems, inaccuracies in location data, system clocks becoming out of sync and tree shading of light sensors are just some of the causes.

The problem for wind farm operators is that when complaints do occur they are extremely difficult to investigate with residents asked to make a note of the times that they experience flicker. This is not only impractical for residents but is inadequate for understanding and resolving the issue.

The advantages of at-property flicker monitoring

Since 2016, Visualwind have been helping wind farm operators to investigate and resolve shadow flicker issues by recording the flicker that occurs at properties. The WindComply monitoring equipment records changes in light intensity and identifies the timings and intensity of shadow flicker as well as identifing which turbine is the cause of the shadow flicker.

Shadow flicker clearly shows up in the high resolution light intensity data

With the data from WindComply, wind operators are able to identity the causes of flicker and take steps to resolve the issues.

Making use of modern IoT technology for long term remote monitoring

For Visualwind, the development of a new monitoring solution for shadow flicker presented various challenges. The equipment would need to run throughout the year with just the power provided by a solar panel. Data would need to be sent via the mobile network regardless of location. And the device would need to be small and enough to sit in or adjacent to the garden of residential property for weeks or months at a time.

These challenges were address with the use of modern IoT technology. The product was built around a low energy industrial computer with extended temperature components. A multiband modem with roaming SIM enabled the transmission of data from any location.

The WindComply system has been in continuous use since 2016 with deployments across the UK and Northern Europe. In each case, the causes of flicker were identified and resolved ensuring that wind farms remained compliant with planning conditions and residents concerns were addressed.

Do get in touch with us to find out more.