Using reanalysis data to quantify extreme wind power generation statistics : a 33 year case study in Great Britain

With a rapidly increasing fraction of electricity generation being sourced from wind, extreme wind power generation events such as prolonged periods of low (or high) generation and ramps in generation, are a growing concern for the efficient and secure operation of national power systems. As extreme events occur infrequently, long and reliable meteorological records are required to accurately estimate their characteristics. Recent publications have begun to investigate the use of global meteorological “reanalysis” data sets for power system applications, many of which focus on long-term average statistics such as monthly-mean generation. Here we demonstrate that reanalysis data can also be used to estimate the frequency of relatively short-lived extreme events (including ramping on sub-daily time scales). Verification against 328 surface observation stations across the United Kingdom suggests that near-surface wind variability over spatiotemporal scales greater than around 300 km and 6 h can be faithfully reproduced using reanalysis, with no need for costly dynamical downscaling. A case study is presented in which a state-of-the-art, 33 year reanalysis data set (MERRA, from NASA-GMAO), is used to construct an hourly time series of nationally-aggregated wind power generation in Great Britain (GB), assuming a fixed, modern distribution of wind farms. The resultant generation estimates are highly correlated with recorded data from National Grid in the recent period, both for instantaneous hourly values and for variability over time intervals greater than around 6 h. This 33 year time series is then used to quantify the frequency with which different extreme GB-wide wind power generation events occur, as well as their seasonal and inter-annual variability. Several novel insights into the nature of extreme wind power generation events are described, including (i) that the number of prolonged low or high generation events is well approximated by a Poission-like random process, and (ii) whilst in general there is large seasonal variability, the magnitude of the most extreme ramps is similar in both summer and winter. An up-to-date version of the GB case study data as well as the underlying model are freely available for download from our website: http://www.met.reading.ac.uk/~energymet/data/Cannon2014/.

Drought risk assessment as changes in the potential stand yield classes and potential forest production for Sitka spruce, Scots pine, and pedunculate oak over the next 80 years in the Great Britain

Probabilistic climate data have become available for the first time through the UK Climate Projections 2009, so that the risk of tree growth change can be quantified. We assess the drought risk spatially and temporally using drought probabilities and tree species vulnerabilities across Britain. We assessed the drought impact on the potential yield class of three major tree species (Picea sitchensis, Pinus sylvestris, and Quercus robur) which presently cover around 59% (400,700 ha) of state-managed forests, across lowland and upland sites. Here we show that drought impacts result mostly in reduced tree growth over the next 80 years when using b1, a1b and a1fi IPCC emissions scenarios. We found a maximum reduction of 94% but also a maximum increase of 56% in potential stand yield class in the 2080s from the baseline climate (1961-1990). Furthermore, potential production over the national forest estate for all three species in the 2080s may decrease due to drought by 42% in the lowlands and 32% in the uplands in comparison to the baseline climate. Our results reveal that potential tree growth and forest production on the national forest estate in Britain is likely to reduce, and indicate where and when adaptation measures are required. Moreover, this paper demonstrates the value of probabilistic climate projections for an important economic and environmental sector.

A selected bibliography on municipal government in Great Britain,

Mode of access: Internet.

Great Britain's share,

Mode of access: Internet.

[Pamphlets on banks and banking law in Great Britain.

[1] Committee of Private Country Banks. Reasons against legislative interference. 1844.--[2] Drummond, Henry. Causes which lead to a bank restriction bill. 1839.--[3] Dun, John. The English bankers' grievance and its proper remedy. 1874.--[4] Greig, J.K. Bank note and banking reform. 1880.--[5] Holdsworth, A.H. A letter to a friend in Devonshire. 1818.--[6] Kinnear, George. Banks and exchange companies. 1847.--[7] A letter to the Right Hon. the Viscount Althorp on his proposed interference with the present system of country banking. 1833.--[8] LLoyds Bank Limited. Permanent staff training. 1919.--[9] [Maclean, A.W.] Additional considerations, addressed to all classes, on the necessity and equity of a national system of deposit-banking and paper currency. 1835.--[10] Nicholson, N.A. The controversy on free banking. 1868.--[11] Steele, F.E. On changes in the bank rate. [1891]--[12] Stirling, James. Practical considerations on banks and bank management. 1865.--[13] Thoughts upon the principles of banks, and the wisdom of legislative interference. 1837.--[14] Watt, Peter. The theory and practice of joint-stock banking. 1836.

Catalogue. Supplement. Newspapers published in Great Britain and Ireland. 1801-1900.

Cover-title.

Great Britain, an empire in transition,

"Selected bibliography": p. 339-342.

Architectura canonica, or, Canons for church architecture : comprising observations thereon, plans, sketches, and illustrations ... with an epistle explanatory to Her Majesty's commissioners for building churches & chapels in Great Britain, Ireland and the colonies /

Mode of access: Internet.

Report from the Select Committee on the affairs of the East India company.

Includes first-fifth reports and appendices.

Endgame for the West in Afghanistan? : explaining the decline in support for the war in Afghanistan in the United States, Great Britain, Canada, Australia, France and Germany /

Analyses of the War in Afghanistan frequently mention the declining or shaky domestic support for the conflict in the United States and among several U.S. allies. This paper dates the beginning of this decline back to the resurgence of the Taliban in 2005-06 and suggests that the deteriorating course of the war on the ground in Afghanistan itself along with mounting casualties is the key reason behind this drop in domestic support for the war.

Treaties, &c., Great Britain, France, America, Russia, the Netherlands & Portugal : with China & Japan.

Mode of access: Internet.

The Newfoundland fishery question and Great Britain & France : the case for England /

Mode of access: Internet.

Great Britain's new allies : the Czecho-Slovaks /

Cover title.