Engineering news
Research published by Imperial College London has revealed that wind turbines installed in the UK will operate at least to their designed lifespan and perform as well as gas turbines.
The results of the study show that 4,246 wind turbines installed in the UK will operate effectively for at least 25 years, with more recently installed turbines running past that.
The results are contrary to a previous study published by the Renewable Energy Foundation (REF) in December 2012, produced by Dr Gordon Hughes, professor of economics at the University of Edinburgh.
Professor Hughes' study suggested that after just ten years the electricity output from wind turbines would decline by a third, making them uneconomic to run and necessitating their replacement with new machines. The research stoked debate about whether wind turbines have a more limited shelf-life than other energy technologies.
According to Imperial College London, the REF study used a statistical model based on average estimates of nationwide wind speeds to determine the wear and tear on the UK's windfarm infrastructure.
However, researchers from Imperial College Business School have improved the study by using local wind speed data obtained from Nasa and data on large gas turbines used in Combined Cycle Gas Turbine power stations. The Nasa data was collected over a 20-year period and measures the wind speed at the exact site of each onshore windfarm in the UK.
The researchers compared the recorded output data from each windfarm and developed a formula to calculate how wear and tear of the machinery affects the performance of the turbines.
The results show that turbines installed in the UK during the 1990s are still producing 75% of their original output after up to 19 years of operation, and will operate effectively for up to 25 years before they need to be replaced.
Furthermore, the research found that turbines installed more recently are performing better than earlier models, suggesting they could have a longer lifespan.
Dr Iain Staffell, co-author of the paper and a research fellow at Imperial College Business School, said that wind turbines' performance decline is similar to the 1-2% annual decline in performance gas turbines in power stations suffer from during their operational lifetime because of wear and tear.
He added that Imperial College had received phone calls from investment firms following the publication of the REF study, asking about the lifespan of the turbines.
"People are investing over a billion pounds a year in these windfarms. They don't want to hear that they have spent a billion pounds on a heap of junk.
"Our study provides some certainty, helping investors to see that windfarms are an effective long-term investment and a viable way to help the UK tackle future energy challenges."
“Windfarms are an important source of renewable energy. In contrast, our dwindling supply of fossil fuels leaves the UK vulnerable to price fluctuations and with a costly import bill.”
In the future, the team aims to study newer windfarms over a longer period to determine if advancements in turbine technology mean they degrade less. This could help the researchers determine more accurately how long newer windfarms will last so that they can calculate their potential long-term economic benefits.
The Renewable Energy Foundation was unavailable for comment.