When a wind turbine blade becomes dislocated, or the gears catch fire, the anti-wind lobby are quick to post videos to gloat and condemn. Yet those occurrences are very rare and new research from the authoritative, 100 years-old, UK Imperial College Business School has shown that wind turbines can remain productive for up to a quarter of a century, making wind farms a good long-term choice for energy investors.
The UK's target is to generate 15% of the nation's energy from renewable resources such as wind and solar power by 2020. There are currently 4,246 individual wind turbines in the UK across 531 wind farms. These generate 7.5% of the UK's electricity. This new research overturns a previous study that used a statistical model to estimate that electricity output from wind turbines declines by a third after only a decade of operation. Some opponents of wind power have argued that older turbines could need replacing wholesale after as little as ten years, which would of course make it an unattractive investment option in economic terms.
There has been some largely uninformed debate about whether wind turbines have less shelf-life than other energy technologies. In this new study, researchers from Imperial College Business School carried out a comprehensive nationwide analysis of the UK fleet of wind turbines, using local wind speed data from NASA.
They showed that the turbines will last their full life of about 25 years before they need to be upgraded.The team found that the UK's earliest turbines, built in the 1990s, are still producing 75% of their original output after 19 years of operation, nearly twice the amount previously claimed, and will operate effectively up to 25 years. This is comparable to the performance of gas turbines used in power stations.
As one might expect, the study also found that more recent turbines, which are more technologically advanced, are performing even better than the earliest models, suggesting they should have a longer lifespan. The team concludes that this makes a strong business case for further investment in the wind farm industry.
Dr Iain Staffell, co-author of the paper and a research fellow at Imperial College Business School, (picture above) said:
"Wind farms 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. However, in the past it has been difficult for investors to work out whether wind farms are an attractive investment. Our study provides some certainty, helping investors to see that wind farms are an effective long-term investment and a viable way to help the UK tackle future energy challenges. "
Professor Richard GreenHead of the Department of Management at Imperial College Business School co-author and Head of the Department of Management at Imperial College Business School, said:
"There have been concerns about the costs of maintaining ageing wind farms and whether they are worth investing in. This study gives a 'thumbs up' to the technology and shows that renewable energy is an asset for the long term."
The researchers reached their conclusion using data from NASA, collected over a two decade period, to measure the wind speed at the exact site of each onshore wind farm in the UK. They then compared this with actual recorded output data from each farm. They then developed and applied a formula that enabled them to calculate how the wear and tear of the machinery affects the performance of the turbines. The previous study only used the average estimates of nationwide wind speeds to determine the effects of wear and tear on wind farm turbines. This is very welcome research and should give a green flag to potential investors in wind farms that they are a good long-term investment.
It doesn't end here: The team aim to study newer wind farms over a longer period to attempt to show that advances in turbine technology means that they are more resilient and are degrading less. This could help the researchers to determine more accurately how long newer wind farms will last so that they can calculate their potential long-term economic benefits.
The study was funded by the Engineering and Physical Science Research Council and by the Alan Howard Charitable Trust.