DONG Energy and ESG complete testing of 28 wind turbine piles

DONG Energy and ESG have successfully completed testing of nearly 28 wind turbine piles on two different onshore sites, in a bid to improve and develop new design methods for offshore wind farms.

The joint industry project PISA had undertaken the testing, while it was conducted to assess and validate a new design method developed by the PISA academic working group led by Oxford University and including Imperial College London and University College Dublin.

The testing was performed to primarily investigate the static monotonic and the response under cyclic lateral loading.

ESG project director Steve Turner said: "The PISA project has provided some of the most challenging testing we’ve ever undertaken. With the largest test, we were simultaneously monitoring more than 250 different precision instruments, whilst applying a load greater than the weight of 37 London double decker busses."

DONG Energy lead geotechnical engineer and PISA Project technical manager Alastair Muir Wood said: "We’re very pleased with the test results, which confirm that traditional design methods in these soils are very conservative. The results indicate that in these site conditions there may be opportunities for savings identified by reducing the quantity of steel in the foundation.

"In other words, there’s a savings potential that will contribute to reducing the cost of electricity."

During the testing in Cowden, England and Dunkirk, France, the piles with a diameter of 2m were supplied by Bladt and Dansteel. Meanwhile, Fibre optic strain gauges for the process were installed by Marmota Industries.

The PISA academic working group is expected to deliver the final report to the project partners by January 2016 after confirming on the new design methods after analysing the data collected.