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DOE to fund Wyoming grid storage study

26 September 2003 – VRB Power Systems Inc. (VRB Power) this week announced the awarding of a Department of Energy funded grant to the State of Wyoming in response to a call for analytical studies of the transmission benefits of deploying hybrid renewable energy-storage systems.

The Wyoming Business Council, in conjunction with Science Applications International Corporation (SAIC), PacifiCorp and VRB Power, submitted the proposal to the US Department of Energy under the State Energy Program Special Projects solicitation. The project is expected to commence by December 1, 2003, with completion anticipated by July 15, 2004.

SAIC will manage the project. Its analysts have years of experience performing objective assessments for the Department of Energy. VRB Power and PacifiCorp will perform the necessary data collection and analysis, including combining wind and battery data into a hybrid system and examining the opportunities for energy storage to relieve transmission congestion and voltage problems, contribute reactive power, and otherwise enhance Wyoming’s ability to export renewable energy.

The transmission system in Wyoming is unable to keep pace with the development of wind farms, particularly in the southwest corner of the state. This is an unusual predicament. The state is blessed with excellent wind resources that a number of utilities from other states have chosen to develop and export to meet the requirements of their particular utility restructuring rules. Wyoming still has not established its own Renewable Portfolio Standard, yet over 150 MW of wind power has been developed in the state since 1999.

Because of increases in system electrical power loads and the reluctance and/or inability of utilities to upgrade or build new power transmission systems, many ageing transmission systems are near their original design capacities and are unable to reliably support existing load requirements. The consequences of this lack of transmission capacity subject many customers to power brownouts and in some cases blackouts as power systems are unable to respond to load requirements. Distributed energy resources, including energy storage, distributed generation, and renewable resources can mitigate this situation and restore stability to the grid while offering the consumer freedom of choice. However, general stability issues, interconnection barriers, and communication must be carefully considered.

The basic reason for transmission system congestion is the non-co-location of generation sources and loads combined with load requirements greater than the transmission capacity. However, the real impact of the overloads is not constant but periodical, infrequent and somewhat seasonal in many parts of the country. On the other hand, many states are instituting renewable energy standards that require a significant amount of electric generation to be provided by renewable resources.

The two most common renewable sources are wind and solar photovoltaic. Both these sources are intermittent. Intermittency can aggravate the congestion and reliability problems of the grid and adversely affects the duty factor of the renewable generation sources. The peak generation of the renewable sources may not coincide with the peak of the load demand. The renewable sources cannot be dispatched on command with any degree confidence. The objective of this Program Category of the solicitation is to investigate how the addition of storage to renewable generation sources (or elsewhere in the grid) can positively affect the reliability of the transmission, relieve transmission congestion and “firm up” the renewable generation sources.

Analysis projects were requested that would evaluate the ability of electric energy storage to positively affect dispatchability of renewable generation sources. This project shall examine the benefit to grid stability of firming up the renewable sources and shall examine the effect on grid congestion of combined renewable generation and electric energy storage facilities. The potential economic advantage of this hybrid system will be addressed considering such aspects as transmission deferral, the effect of real time pricing, the ability to enter into the day ahead markets and the ability to move energy generated during off-peak hours into the on-peak market. Quantitative estimates shall be developed for all these tasks. An examination of the applicable renewable state energy portfolio standards shall be made to determine institutional barriers and opportunities for energy storage.