The wholesale electricity market is picking up speed through the introduction of standardized intra-hour transmission scheduling among a broad group of western utilities.

Power producers and others will now have the option of buying, selling and transmitting energy across multiple transmission systems on a half-hour basis instead of an hourly basis. The shorter timeframe provides more market flexibility to respond to unexpected changes in power generation and demand and make more effective use of available transmission lines to deliver energy.

The shift to standardized intra-hour scheduling is a cooperative effort of the Joint Initiative, which is supported by three sub-regional transmission groups in the Western Interconnection: Northern Tier Transmission Group, ColumbiaGrid and WestConnect. Participating utilities include Avista, Bonneville Power Administration, Chelan County Public Utility District, Grant County Public Utility District, Idaho Power Company, NorthWestern Energy, PacifiCorp, Puget Sound Energy, Portland General Electric, Salt River Project, Seattle City Light, Southwest Transmission Cooperative, Tacoma Power, Xcel Energy/Public Service Company of Colorado and Western Area Power Administration. Additional utilities will also offer intra-hour scheduling following necessary approvals.

“This is one of the most significant changes in the West’s wholesale electricity market in many years,” said Brian Silverstein, senior vice president of transmission services at BPA. “It’s the result of strong regional collaboration to make wholesale energy markets more flexible and responsive to the changing needs of the power system.”

The introduction of intra-hour scheduling comes amid heightened efforts to balance the variable output of the region’s growing fleet of wind energy projects. By the end of 2011, the Pacific Northwest will have more than 6,000 megawatts of installed wind generation, and participating utilities in the Desert Southwest and Rocky Mountain regions anticipate about 2,600 megawatts of wind generation and 150 megawatts of solar generation. Intra-hour scheduling and other potential balancing solutions will help maintain reliability as wind and solar generation varies and keep costs to consumers as low as possible.

“Intra-hour transmission scheduling will help the industry be more responsive to unanticipated changes in generation or load,” said Doug Butler, vice president for systems operations at PacifiCorp, a major western power generator and transmission line owner/operator. “Being able to fine-tune the transmission system in this way will provide better reliability and a more efficient use of the transmission network. In the end, that benefits our customers.”

Power producers could benefit by finding buyers for additional power available over shorter periods, such as when unexpected surges in wind generate extra electricity, or to draw on more widespread energy resources to fill gaps when generation declines.

The Joint Initiative parties are also developing a web-based Intra-Hour Transaction Accelerator Platform to help parties identify opportunities for intra-hour transactions, assess available transmission and efficiently complete the transactions. The platform, called webExchange, will be operational this fall and is currently available for subscription from Open Access Technology International Inc.