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Western Wind and Solar Integration Study

Map of the Western Electricity Coordinating Council operation area. It includes most of Montana and New Mexico as well as Wyoming, Colorado, Idaho, Utah, Arizona, Nevada, Washington, Oregon, and California. Within this area is WestConnect, which includes all or portions of Wyoming, Colorado, New Mexico, Utah, Arizona, and Nevada.

WestConnect is a group of utilities that operates within a larger area managed by thethe larger Western Electricity Coordinating Council (WECC) regional reliability entity.

The Western Wind and Solar Integration Study, one of the largest regional solar and wind integration studies to date, explores the question: Can we integrate large amounts of wind and solar energy into the electric power system of the West?

Phase 1 Research

The first phase of the Western Wind and Solar Integration Study investigated the benefits and challenges of integrating up to 35% wind and solar energy in the WestConnect subregion and, more broadly, the Western Interconnection, in 2017. The study showed it is operationally possible to accommodate 30% wind and 5% solar energy if utilities substantially increase their coordination of operations over wider geographic areas and schedule their generation and interchanges on an intra-hour basis.

Key Findings

  • The integration of 35% wind and solar energy into the electric power system will not require extensive infrastructure if changes are made to operational practices.

  • Wind and solar energy displace fossil fuels. A 35% penetration of solar and wind power would reduce fuel costs by 40% and carbon emissions by 25%–45%—the rough equivalent of taking 22–36 million cars off the road—compared to today's system.

  • Increasing the size of the geographic area over which the wind and solar resources are drawn substantially reduces variability.

  • Scheduling generation and interchanges subhourly reduces the need for fast reserves.

  • Using wind and solar forecasts in utility operations reduces operating costs by up to 14%.

  • Existing transmission capacity can be better used. This will reduce new transmission needs.

  • Demand response programs can provide flexibility that enables the electric power system to more easily integrate wind and solar—and may be cheaper than alternatives.

Phase 2 Research

Current analysis is examining the impacts of increased penetrations of wind and solar energy on the cycling and ramping of conventional coal and gas generators in the West. Measured emissions from each plant in the West and wear-and-tear costs of conventional generators are being incorporated to more fully investigate the operational impacts of wind and solar energy.

Key findings include:

  • Fuel and emissions costs decrease as more wind and solar energy are added.

    Chart of annual operating costs in WECC showing four cases. They are: (1) no wind/solar = $50 billion, 10% wind/1% solar = approximately $41 billion, 20% wind/3% solar = approximately $32 billion, and 30% wind/5% solar = $30 billion.

    Higher penetrations of wind and solar energy result in lower annual operating (fuel and emissions, assuming a $30/ton of carbon dioxide tax) costs in WECC.

  • Carbon dioxide emissions decrease as more wind and solar are added.

    Graph of carbon dioxide emissions in millions of tons per year for four cases. They are: (1) No wind/solar = 500 million tons, 10% wind/1% solar = approximately 460 million tons, (3) 20% wind/3% solar = 400 million tons, and (4) 30% wind/5% solar = approximately 380 million tons.

    Higher penetrations of wind and solar energy result in decreasing carbon dioxide emissions for a $9.50/MBTU gas price. At a gas price of $3.50/MBTU, emissions reductions are much greater because coal is displaced instead of gas.

  • Wind and solar variability decreases for larger geographic footprints.

    Chart of variability increase in percent for four cases. They are: (1) Tri-State = approximately 5,200%, Wyoming = approximately 600%, WestConnect = approximately 100%, and WECC = approximately 100%.

    In the high wind/solar case, the variability that a small area, such as the Tri-State zone in Wyoming, must manage is many times more than the variability that a single state or large region must manage. This is why coordination of operations is needed over wider geographic areas.

For More Information

For more information about the Western Wind and Solar Integration Study, see the following resources. Additional publications can be found in the NREL Publications Database.

Phase 1 Publications

Phase 2 Publications

Wind Data

Contact

Debra Lew
303-384-7037