Minimising piling noise from offshore wind farm construction

Piling noise from the construction of offshore wind farms can be an issue of concern to coastal communities and needs careful assessment, says Jonathan Sims.

Due to the increasing desire for renewable energy and the reduced acceptability of onshore wind developments, the past few years have seen an increase in the development of large offshore wind farms in the UK. 

While these are generally too far offshore for operational noise to be a concern, the construction of offshore turbines frequently requires piles to be driven into the seabed during construction of the turbine foundations. Installation of offshore piles can only be carried out under calm sea conditions and relatively low wind speeds, and so to minimise construction periods, piling is usually undertaken whenever weather conditions allow.  

Piling noise – potential audibility

Offshore wind farms are generally five to 30km offshore and therefore most aspects of development would not be expected to generate high levels of noise onshore. The exception is offshore piling which, depending on weather conditions, can be clearly audible. 

This is indicated in the graphs above, which show measured noise levels in the early hours of the morning at onshore locations during offshore piling, 15-20km from the measurement location. The “thump” of the pile hammer is indicated in red - piling was clearly audible.

Predicting noise levels 

Typical engineering noise prediction methods are not able to accurately predict noise propagation over long distances, or account for the strong effect meteorological conditions can have on noise propagation when coupled with the effect of the acoustically reflective sea surface. However, it is possible to predict noise propagation using advanced parabolic equation methods. The blue graphs above show modelled results demonstrating the change in noise propagation under downwind conditions, but with increasing wind shear. These show that under extreme wind shear conditions sound is trapped in a layer close to the sea surface, which increases noise levels onshore.

Assessment methods

In the UK, construction noise is usually assessed using British Standard BS 5228. This standard contains example criteria that suggest that, during night-time, an acceptable level of noise from construction is up to 45 to 55 dB LAeq. This noise level would be clearly audible in most areas of the UK. Given that offshore piling for a large wind farm can span three to five years, these noise levels may well result in complaints. 

To address this, it is advisable to monitor noise from piling during construction. Given that piling only occurs when weather conditions permit, and variations in weather conditions can result in very different onshore noise levels, it can be difficult to for a short-term survey to capture typical piling noise levels. So, long-term monitoring is required.

Long-term noise monitoring during construction 

Long-term monitoring can be carried out remotely using equipment such as that shown below. Such systems have been successfully installed at several sites in the UK, and operate from mains-derived power supplies and use broadband internet connections. This means that measured data is immediately available in the event of a noise complaint and that systems can operate unattended for several years, with only occasional maintenance visits.



Given the continuing desire for renewable energy, the development of large offshore wind farms is likely to increase in the next decade. Public support is key to the success of these projects and it is therefore crucial that construction noise is assessed and monitored to ensure any disturbance to residents is minimised, particularly during the sensitive night time hours.

Jonathan Sims is an executive acoustics engineer at Hoare Lea Acoustics.


Please can we minimise the piling noise on the off shore wind farm from after 21.00 please. Drives me crazy after a days work.