Western Wind and Solar Integration Study
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.
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.
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.
Carbon dioxide emissions decrease as more wind and solar are added.
Wind and solar variability decreases for larger geographic footprints.
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
Western Wind and Solar Integration Study: Executive Summary
This report provides a summary of background, approach, and findings of Phase 1 of the Western Wind and Solar Integration Study
Western Wind and Solar Integration Study
This report provides a full description of Phase 1 of the Western Wind and Solar Integration Study and its findings.
How Do High Levels of Wind and Solar Impact the Grid? The Western Wind and Solar Integration Study
This paper is a brief introduction to the scope, inputs and scenario development, and key findings of Phase 1 of the Western Wind and Solar Integration Study.
Value of Wind Power Forecasting
This study, building on the extensive models developed for the Western Wind and Solar Integration Study, evaluates the operating cost impacts of improved day-ahead wind forecasts.
Impact of High Solar Penetration in the Western Interconnection
This paper presents an overview of the variable characteristics of solar power as well as the accompanying grid dynamic performance and operational economics for a system with significant solar generation.
Impact of High Wind Power Penetration on Hydroelectric Unit Operations in the WWSIS
This report examines the impact of wind penetration on hydroelectric unit operations.
Phase 2 Publications
The Western Wind and Solar Integration Study
This fact sheet summarizes the goals and initial findings of the Western Wind and Solar Integration Study Phase 2.
Impacts of Wind and Solar on Fossil-Fueled Generators
This analysis considers the cost and emissions impacts of cycling and ramping of fossil-fueled generation to refine assessments of wind and solar impacts on the power system.
Power Plant Cycling Costs
This report examines wear-and-tear costs and impacts of cycling and ramping on fossil-fueled generators.
Analysis of Cycling Costs in Western Wind and Solar Integration Study
This analysis examines the additional cycling costs of the thermal fleet.
Western Wind Dataset
Access to and information about the dataset used for the Western Wind and Solar Integration Study.
Development of Regional Wind Resource and Wind Plant Output Datasets
This report describes the development of the wind and solar datasets used in the Western Wind and Solar Integration Study.