Grid Integration Studies
A grid integration study is an analytical framework used to evaluate a power system with high penetration levels of variable renewable energy (RE). Generally, a grid integration study:
- Simulates the operation of the power system under different variable RE scenarios;
- Identifies reliability constraints; and
- Evaluates the cost of actions to alleviate those constraints.
The variable RE scenarios in a grid integration study establish where, how much, and over what timeframe to build generation and transmission capacity, ideally capturing the spatial diversity benefits of wind and solar resources. The results help build confidence among policymakers, system operators, and investors to move forward with plans to increase the amount of VRE on the grid.
This webinar addresses fundamental questions about grid integration studies, best practices for engaging key stakeholders, and the kinds of analysis and data that are involved in conducting a grid integration study. It includes several case studies to highlight lessons learned.
Federal Electricity Regulatory Commission, 2016
This white paper identifies guiding principles that can assist power system planners in conducting analysis of grid reliability impacts associated with meeting carbon dioxide emission reduction targets, with specific reference to the United States’ Clean Power Plan (CPP). The CPP, issued in August 2015 by the U.S. Environmental Protection Agency, sets limits on carbon dioxide emissions from existing fossil fuel-fired generators, and requires states to consider grid reliability impacts in their compliance plans. This white paper aims to promote robust analysis of the reliability impacts of the CPP by recommending guiding principles related to: 1) transparency and stakeholder engagement; 2) study methodology and interactions between studies; 3) study inputs, sensitivities and probabilistic analysis; and 4) tools and techniques. Though specifically crafted with reference to the CPP, the principles and analysis considerations presented in this white paper are generally applicable to other grid integration studies in different power system contexts.
International Energy Agency Wind Task 25 (IEA Wind), September 2013
Based on more than 8 years of work by the IEA Wind Task 25 (Design and Operation of Power Systems with Large Amounts of Wind Power), this Expert Group Report represents the best available synthesis of current knowledge on conducting large-scale wind integration studies. The recommendations presented in the report are generally applicable to the development of wind integration studies within a variety of country- and/or system-specific contexts. The report also contains a section-by-section reference list of technical literature for further reading.
NREL, August 2015
This white paper provides guidance for Mexico’s electricity system planners and other stakeholders on how to develop a comprehensive grid integration study. Drawing from the IEA’s Expert Group Report on Recommended Practices 16. Wind Integration Studies, this report contextualizes recommendations and best-practices specifically to support Mexico’s goals of increasing the contribution of RE to the nation’s electricity supply. Throughout the report, the authors provide expert insights into how Mexico can prioritize near-term versus long-term data collection, analyses, and other actions to understand and address the impacts of higher wind and solar penetration levels associated with Mexico’s 35% by 2024 RE goal.
Utility Variable-Generation Integration Group (UVIG)
UVIG—a forum for practitioners that provides resources for information on the status of wind and solar technology deployment—curates a list of grid integration studies and summary reports. Many reference documents for the studies cited in the Grid Integration Study Examples below (among others) can be found in this library.
Grid Integration Study Examples
National Renewable Energy Laboratory, 2016
This study analyzes the ability of the Eastern Interconnection of the United States, one of the largest power systems in the world, to accommodate high penetrations of wind and solar power. Using advanced modeling and computing techniques, the project team simulated the large-scale adoption of wind and solar energy at a temporal resolution up to 5 minutes. The study represents the cutting-edge of power system modeling, employing a high spatial resolution to include all synchronous components of the Eastern Interconnection. Results suggest that the Eastern Interconnection can reliably integrate upwards of 30% variable renewable energy in the power mix. However, meeting the 30% target will require increased balancing area coordination, incentives for transmission and generation to provide necessary ancillary services, and increased flexibility of traditional generators. In addition to the technical report, the full dataset as well as animations showing net interchange for two study scenarios are available for free download.
National Renewable Energy Laboratory, 2010-2014
The Western Wind and Solar Integration Study examines the benefits and challenges of integrating significant wind and solar energy to the Western Interconnection, which covers the power system operated by the WestConnect group of utilities in Arizona, Colorado, Nevada, New Mexico and Wyoming. The study consists of three phases. Phase 1 investigates the operational impacts of increasing the penetration of wind, solar photovoltaics (PV), and concentrating solar power to up to 35% in 2017. Phase 2 analyzes the wear-and-tear costs and emissions impacts associated with increased cycling by conventional generation due to wind and solar integration. Phase 3 evaluates the transient stability and frequency response of the Western Interconnection under high penetration solar and wind scenarios and identifies ways to mitigate adverse impacts through transmission reinforcements, storage, advanced control capabilities, and other mechanisms.
National Renewable Energy Laboratory, 2010
The Eastern Wind Integration Transmission Study examines the operational impact of up to 20-30% wind energy penetration in the Eastern Interconnection, one of the three synchronous grids in the contiguous United States. The study addresses a variety of issues related to wind energy and transmission development, including the costs, impacts, and enabling mechanisms (e.g., geographic diversity, forecasting, operating reserves) associated with significant wind penetration. A follow-on study, the Eastern Renewable Generation Integration Study, is anticipated to be released in winter, 2015.
European Network of Transmission System Operators for Electricity (ENTSO-E), 2010
Initiated by the European Network of Transmission System Operators for Electricity (ENTSO-E), this study evaluates transmission-related challenges associated with four wind penetration growth scenarios (no wind growth from 2008 levels, best estimate of wind growth, optimistic but feasible growth, and growth when further grid enhancements are made beyond 2015). The study includes recommendations related to network finance, reinforcements, grid security and flexibility, consents, coordinated operation, grid code, network access rules, market development, offshore grids, and control of wind generation.
National Renewable Energy Laboratory, 2013
Developed in response to the ambitious RE targets established by the Hawaii Clean Energy Initiative, the Hawaii Solar Integration Study evaluates the operational impacts of high penetrations of solar PV (including both centralized and distributed PV) on the electricity grids of two Hawaiian islands: Maui and Oahu. The two islands provide examples of small power grids with differing levels of firm and RE capacity. The study examines variability, the ability to curtail power output, grid support, and load characteristics in the context of increasing variable RE on these systems. The technical reports underlying the summary are available here.
Independent System Operator (ISO) New England, 2010
ISO New England (which serves as the regional transmission organization for the New England region of the United States) commissioned the New England Wind Integration Study to assess the operational, planning, and market impacts of integrating up to approximately 12GW of wind power. The study finds that wind energy could supply up to 24% of New England’s total annual electricity needs by 2020 if the system implements transmission upgrades.
Ireland Department of Communications, Energy and Natural Resources, 2008
The All Island Grid Study represents a comprehensive assessment of the power system on the island of Ireland to accommodate significant renewable energy penetration (including variable RE as well as dispatchable RE resources) by 2020. The study is divided into four “workstreams:” resource assessment, portfolio screening study, dispatch study, network study, and costs and benefits. The results include the climate change and energy security impacts, as well as the investment costs, associated with the RE scenarios.
Electricity Reliability Council of Texas, 2008
The Electricity Reliability Council of Texas (ERCOT) commissioned this study of the ancillary services requirements for its system to accommodate up to 15,000 MW of wind energy. The Study evaluates and makes recommendations related to the methodology used by ERCOT to determine ancillary service needs; estimates the impacts of wind generation on the costs of ancillary services; and identifies changes to procedures related to severe weather conditions. ERCOT re-evaluated—and largely validated—the results of this study in a 2013 update.