Tom Ackers, Department of Mechanical Engineering, Northern Arizona University, Special Issue Editor
Electricity produced from utility-scale wind power plants has increased tremendously over the past decade, tripling from just over 30,000 MW installed world-wide in 2003 to in excess of 90,000 MW at the beginning of 2008. This ever-growing amount of wind power has risen to the point where its influence on electrical system operation can be a significant factor requiring additional planning and modified operation. A large transmission grid is typically broken into several smaller transmission "balancing areas" in which reliability requirements are met while balancing loads with generation. These balancing areas vary in size from less than 1000 MW to over 50,000 MW. Within any given balancing area there may be several different types of generators, including natural gas combustion turbines, coal-fired steam plants, nuclear power, hydro power, combined heat and power, wind energy, and perhaps others. The average load within a balancing area typically varies in predictable daily and seasonal patterns, but also contains an unpredictable component due to random load variations, uncertainties in the load forecasts, as well as unforeseen events. In order to compensate for these variations and unforeseen events, steps are taken to ensure system reliability by having flexible generation capacity on-line to provide regulation and load following or set aside as reserves to account for load forecast errors, unforeseen events, and unplanned outages. Introducing wind generation into a balancing area can increase the regulation and load following burden and need for reserves, due to its natural variability. However, since the balancing area has a constantly varying load, the impact of the wind plant variability imposed on the load variability may range from negligible to significant depending upon the level of penetration (i.e., the peak capacity of wind power compared to the peak balancing area load), and other system characteristics such as its interconnection with other balancing areas, the flexibility of its generation resources, and the variability of the wind resource itself.
Generally speaking, when the wind penetration climbs to 1 or 2% of the balancing area load, the affected system operator typically wants to know how to best plan for and handle the impact of the wind's inherent variability and uncertainty. At current levels of wind energy, balancing areas penetration levels are frequently quite small, but do vary up to nearly 50% (Denmark) where at times the wind energy can be greater that 100% of the load. Thus there is operational experience with low to high levels of wind power that provide valuable guidance in understanding the utility system impacts of wind energy. Because all balancing areas differ to some degree, whether it is their physical system characteristics, methods of operation or the market within which they operate, the present experience will not necessarily apply to other utility systems. Since the turn of the century, several wind integration studies have been conducted with the intent of understanding system impacts given the unique attributes of each balancing area. However, the models and methods employed to assess these impacts are constantly evolving, and widely disseminating their results if of critical value to both utilities and wind energy communities. Evidence of this is provided by the important forums that have arisen that deal specifically with wind integration issues, such as the Utility Wind Integration Group (UWIG) and the related R&D tasks of the International Energy Agency.
While it is the intention of the Wind Engineering to continually publish articles related to all aspects of wind engineering, this topic merits special consideration through an issue devoted entirely to the subject. Thus, it is the purpose of this issue to present the study methods and results from recent important studies related to wind power integration into the utility system. Please submit all papers for this special issue (by March 31, 2008) to:
Professor Tom Acker
Department of Mechanical Engineering, Northern Arizona University, P.O. Box
15600, S. McConnell Drive, Bldg. 69, Flagstaff, Arizona, 86011 USA
Tom.Acker@nau.edu
click below to contact the editor, Prof. Jon McGowan, directly: jgmcgowa@ ecs.umass.edu
If so, you/your institution qualifies for a half price subscription. E-mail us with the details, and we'll organise it. (This also applies to papers submitted but not yet published).
Editor for 2007
Prof. John Twidell
Amset Centre, Horinghold, Leicestershire LE16 8DH, UK
amset@onetel.com
Editor from 2008
Prof. Jon McGowan
Renewable Energy Research Lab, University of Massachusetts
jgmcgowa@ecs.umass.edu
Editorial board
Ian Baring-Gould
National Renewable Energy Laboratory, 1617 Cole Boulevard, Golden, Colorado
80401-3393, USA
ian_baring-gould@nrel.gov
Tony Burton
Tynyreithin, Carno, Powys SW1T 5JS UK
alb@tynyreithin.demon.co.uk
Dr Jim Halliday
Head, Energy Research Unit, Rutherford Appleton Laboratory, Didcot OX11 0QX
UK
j.halliday@rl.ac.uk
Dr Lars Landberg
Head of Meteorology, Wind Energy Dept, Risø National Laboratory, Roskilde,
DK 4000,Denmark
lars.landberg@risoe.dk
David Sharpe
Centre for Renewable Energy and Sustainable Technology (CREST), University
of Loughborough, LE11 3TU, UK
d.j.sharpe@lboro.ac.uk
Associate Professor David Wood
Dept Mechanical Engineering, University of Newcastle, NSW 2308, Australia
medhw@cc.newcastle.edu.au
Ing. Rafael Olivia
Universidad Nacional de la Patagonia Austral, Casillo de Correo 73; (or: Sistemas
de Energía Renovable, Teófilo de Loqui 58) 9400 Rio Gallegos - Argentina
roliva@lyr-ing.com
Prof Janardan Rohatgi
Dept of Mechanical Engineering, Federal University of Pernambucp, Recife,
Brazil
windcenter@npd.ufpe.br
Prof Gaetano Gaudiosi
OWEMES Association, Via Antonio Serra, 62 00191 -Roma, Italy
gaetanogaudiosi@hotmail.com
gaudiosi@owemes.org