The Intermittency Report

An Assessment of the Evidence on the costs and impacts of intermittent generation on the British electricity network.


UKERC's report represents a definitive picture of the costs and impacts of intermittent energy supplied by renewable sources, such as wind.  Some commentators have suggested that renewable energy is made much more costly, or is drastically limited by intermittency.  The report finds that these views are out of step with the vast majority of international expert analysis and that intermittency need not present a significant obstacle to the development of renewable sources.

pdf Main Report  

icon Keynote speech, Graeme Sweeney, Executive Vice President Shell Renewables, Hydrogen and C02 

icon Launch presentation, Rob Gross and Professor Tim Green 

Press release: UK Energy Research Centre Dispels Myths Surrounding Intermittent Renewable Energy

Journal Articles:

Skea, J., Anderson, D., Green, T., Gross, R., Heptonstall, P., Leach, M. (2008) Intermittent renewable generation and the cost of maintaining power system reliability, IET Generation, Transmission and Distribution, Vol. 2 (1) pp. 82-89

Gross, R., Heptonstall, P., Leach, M., Anderson, D., Green, T., Skea, J. (2007) Renewables and the grid: Understanding intermittency, Proceedings of the Institution of Civil Engineers, Energy, Vol. 160 (1) pp. 31-41


Supporting Papers

icon  Methods for Reporting Costs Related to the Capacity Credit of Intermittent Generation Relative to Conventional Generators (111.29 KB)

icon  Power System Reserves and Costs with Intermittent Generation (584.94 KB) 

icon  Intermittency Assessment Scoping Note and Protocol (97.5 KB)

Preliminary Outputs

icon  Key Issues Paper for Expert Groups (67.96 KB), Expert Group Meeting (June 2005)   

Stakeholder Workshop (July 2005):  


icon  UKERC TPA presentation to stakeholders (66.16 KB), 

icon  Workshop Summary (53.8 KB) 

Invited Presentations

icon  Hugh Sharman, independent consultant (2.54 MB) 

icon  Graham Sinden, ECI, Oxford University (1.05 MB) 

(please note that the invited presentations represent their author's views, not those of UKERC)