June 19th, 2017 by Joshua S Hill
A new study published this month has concluded that wind turbines appear to work extra hard on the coldest-of-cold days, providing much-needed electricity during some of the highest demand periods, while offshore wind energy serves as an even more secure source of electricity generation during cold weather.
We can all agree that renewable energy sources such as wind are a necessary tool in decarbonizing the global energy sector, and have time and again proven themselves to also be an economically viable, if not economically preferable option for developers and countries the world over. This is why we place so much emphasis on reporting news of new wind energy developments, technological innovations, and cost decreases. However, it is as important that we pay some attention to the efficiency and efficacy of renewable energy sources, and time understanding their hidden benefits and pitfalls.
Recently, scientists from the UK Met Office Hadley Centre, Imperial College London, and the University of Reading, set out to study the efficacy of wind energy generation in different temperatures. They found that, due to prevailing wind patterns, cold days in the UK often yield less wind energy because the winds are calmer, and warmer days see higher winds. However, what was most interesting about their discoveries was that during the very coldest days — the highest 5% of energy demand days — a third of these days saw wind energy actually produce above-average output, due to more of these days having strong easterly winds.
“The very coldest days are associated with a mix of different weather patterns, some of which produce high winds in parts of Great Britain,” said Hazel Thornton, of the Met Office Hadley Centre, and one of the paper’s authors. “During winter in the UK, warmer periods are often windier, while colder periods are more calm, due to the prevailing weather patterns. Consequently, we find that in winter as temperatures fall, and electricity demand increases, average wind energy supply reduces.“
“However, contrary to what is often believed, when it comes to the very coldest days, with highest electricity demand, wind energy supply starts to recover,” Thornton added. “For example, very high pressure over Scandinavia and lower pressure over Southern Europe blows cold continental air from the east over Great Britain, giving high demand, but also high wind power. In contrast, winds blowing from the north, such as happened during December 2010, typically give very high demand but lower wind power supply.”
The paper, The relationship between wind power, electricity demand and winter weather patterns in Great Britain, was published this week in the journal Environmental Research Letters, and serves to increase our understanding of how best to develop and grow wind energy. For example, the research suggests that a wide spread of wind turbines around the UK would allow the country’s wind generation to account for varied wind patterns, and to make the most of those wind patterns on the coldest days.
“A wind power system that is distributed around Great Britain is less influenced by low generation on cold, still winter days: low wind in one region tends to be compensated by wind elsewhere,” explained Professor Sir Brian Hoskins, of the University of Reading and Chair of Imperial College London’s Grantham Institute – Climate Change and the Environment, who also served as one of the paper’s authors. “The average drop in generation is only about a third, and is generally smaller than this on the really cold days.”
Further, the report found that offshore wind provides a more secure supply of electricity during high demand periods compared to onshore wind, due to the inherent nature of offshore wind having access to more sustained and high-level winds. Specifically, the authors of the report note that, “Offshore wind power is sustained at higher levels and offers a more secure supply compared to that onshore.”
Currently, the United Kingdom has halted onshore wind development, saying that there is enough onshore wind capacity currently installed around the country — though, in all likelihood, a lot of the reasoning behind this decision stems from growing community frustration for the sight of wind turbines. However, the UK is barreling forward on offshore wind, with numerous projects currently under construction or in the pipeline.