Golden, CO and Washington, DC, U.S.A. — (METERING.COM) — December 20, 2011 – It is technically possible to integrate up to 35 percent renewable electricity to the U.S. grid if infrastructure and operational improvements can be made, and the experiences of operators are pointing the way to doing this, two recent reports show.
Two studies from the National Renewable Energy Laboratory (NREL) investigated the potential in the eastern and western transmission systems. The first, the “Eastern Wind Integration and Transmission Study” (EWITS), explored the impact of shifting up to 20 percent–30 percent of the power in the Eastern Interconnect of the U.S. to wind energy by 2024. No fundamental technical barriers were found to the integration of 20 percent wind energy into the electrical system, although transmission planning, system operation policy, and market develop¬ment would need to continue to evolve for this penetration level to be achieved.
The companion study, the “Western Wind and Solar Integration Study” (WWSIS), looked at adding enough wind and solar power capacity to the grid to produce 35 percent of the WestConnect’s electricity by 2017. WestConnect is a group of utilities in Arizona, Colorado, Nevada, New Mexico, and Wyoming that are working to enhance wholesale electricity markets in the West. The study showed that it is operationally possible to accommodate 30 percent wind and 5 percent solar energy penetration in the West – as long as utilities sub¬stantially increase their coordination of operations over wider geographic areas and schedule their generation deliveries on a more frequent basis than the hourly time¬tables currently in use.
The second study by Alstom Grid for the U.S. Department of Energy, reviews the practices of 33 grid operators in 18 countries as they integrate increasing larger amounts of wind into the power grids. Among the findings are that wind power forecasting is the most important pre-requisite for successful integration, with centralized forecasting the best approach. Grid operators also need to be equipped with the necessary decision support tools in control rooms, such as voltage stability and transient stability analysis, and new policies should be designed for the sub-hourly scheduling and dispatch of resources.
“The industry is on the verge of a new operating paradigm as high levels of wind and other variable generation and increasing operational uncertainty become the norm today and even more so as we move towards 2030,” the report notes.