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Resource Adequacy
ERCOT counts on an adequate supply of electric generation to meet demand and maintain capacity reserves to help support grid reliability if shortfalls occur.
This section includes access to ERCOT market studies and analysis materials related to resource adequacy as well as ERCOT short- and long-term forecast reports on generation supply and demand.
Reports produced prior to 2012 are located in the yearly archive section of Reports and Presentations
All other archives are located at the bottom of the page.
Drought Risk
ERCOT developed a drought risk monitoring tool to screen for potential drought-related impacts to generation resources. The tool predicts whether water supplies used by generation resources in the ERCOT region are at risk of reaching levels requiring closer monitoring over the next 6 to 18 months, based on the most recent reservoir and lake levels from the Texas Water Development Board (TWDB) and historical trends in water usage. The documents available in this section include summaries of the results of this analysis, documentation of the tool methodology, and other related reports.
Drought Risk Analysis Reports
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ERCOT Drought Risk Prediction January 2021
(Feb 03, 2021 – pdf – 155.1 KB) -
ERCOT Drought Risk Prediction October 2020
(Nov 05, 2020 – pdf – 311.6 KB)
Related Documents
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Reservoir Prediction Example
(Apr 26, 2016 – xlsx – 230 KB)
Monthly Generator Interconnection Status Reports
View the latest public interconnection information on generation resources in the ERCOT region.
Resource Capacity Trend Charts
Charts and accompanying data showing annual and monthly changes in resource capacity by fuel type for the ERCOT Region, incorporating both historical additions and planned projects being studied as part of the interconnection request process. The chart are updated on a monthly basis, and include natural gas, wind, solar, and battery storage resource types.
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Capacity Changes by Fuel Type Charts, January 2021 monthly
(Feb 05, 2021 – xlsx – 62.8 KB) -
Capacity Changes by Fuel Type Charts, January 2021
(Feb 03, 2021 – xlsx – 85.7 KB) -
Capacity Changes by Fuel Type Charts, December 2020 monthly
(Jan 11, 2021 – xlsx – 60.8 KB) -
Capacity Changes by Fuel Type Charts, December 2020
(Jan 07, 2021 – xlsx – 84.6 KB)
Resource Adequacy Assessments
Seasonal Assessment of Resource Adequacy (SARA)
The SARA report serves as an early indicator of the risk that ERCOT may need to call an Energy Emergency Alert Level 1 (EEA1) due to having insufficient operating reserves during seasonal peak electric demand periods. It uses a scenario approach to illustrate a range of resource adequacy outcomes based on extreme system conditions. The SARA report relies on projected resource capabilities and peak demand forecasts similar to the CDR report. However, unlike the CDR, it incorporates generator outage trends to determine the expected amount of resource capacity available for operating reserves.
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Spring 2021 Preliminary Seasonal Assessment
(Nov 05, 2020 – xlsx – 143.2 KB) -
Spring 2021 Preliminary Seasonal Assessment
(Nov 05, 2020 – pdf – 301.9 KB) -
Winter 2020-21 Final Seasonal Assessment
(Nov 05, 2020 – xlsx – 138.2 KB) -
Winter 2020-21 Final Seasonal Assessment
(Nov 05, 2020 – pdf – 357.5 KB) -
Winter 2020-21 Preliminary Seasonal Assessment
(Sep 02, 2020 – xlsx – 133.4 KB) -
Winter 2020-21 Preliminary Seasonal Assessment
(Sep 02, 2020 – pdf – 290.9 KB)
Capacity, Demand and Reserves (CDR) Report
This biannual report contains a multi-year forecast of summer/winter peak electricity demand and expected generation resources, along with the calculation of Planning Reserve Margins (PRMs). The PRM represents the excess resource capacity available to cover uncertainties in future peak electricity demand, generator availability and new resource supply. The PRM is expressed as a percentage of firm peak demand (i.e., demand that is not subject to interruption in exchange for incentive payments).
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Capacity, Demand and Reserves Report December 2020
(Dec 16, 2020 – xlsx – 461.5 KB) -
Capacity, Demand and Reserves Report December 2020
(Dec 16, 2020 – pdf – 1.2 MB)
Planning Reserve Margin Analysis
This section consists of documents and data files pertaining to the Economically Optimum Reserve Margin (EORM) reporting initiative, which was authorized by the Public Utility Commission of Texas as part of Project Number 42302, "Review of the Reliability Standard in the ERCOT Region." The current minimum target reserve margin established by the ERCOT Board of Directors is 13.75 percent of peak electricity demand to serve electric needs in the case of unexpectedly high demand or levels of generation plant outages.
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Final 2020 ERCOT Reserve Margin Study Report, 1-15-2021
(Jan 15, 2021 – pdf – 3 MB) -
2020 ERCOT Reserve Margin Study, Responses to Questions & Comments, 1-15-2021
(Jan 15, 2021 – pdf – 279 KB) -
2020 ERCOT Reserve Margin Study Report, Public Draft, 12-01-2020
This draft report describes the results and modeling approach for estimating the Market Equilibrium and Economically Optimal reserve margins (MERM and EORM, respectively) for study year 2024. ERCOT stakeholder comments on the draft report are due December 30, 2020.
(Dec 01, 2020 – docx – 3.3 MB) -
ERCOT Study Process and Methodology Manual for EORM/MERM 12-12-2017 v1.0
Final document version with responses to stakeholder comments incorporated
(Dec 12, 2017 – docx – 756.2 KB)
Wind and Solar
Wind and solar profiles for use in ERCOT planning studies, as well as files showing the derivation of wind and solar peak average capacity percentages using approved CDR methodologies.
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CDR Summer 2020 Peak Average Wind Capacity Percentages, 11- 23-2020
(Nov 30, 2020 – xlsx – 93.7 KB) -
CDR Summer 2020 Peak Average Solar Capacity Percentages, 11-23-2020
(Nov 30, 2020 – xlsx – 18.7 KB) -
ERCOT Wind Profiles, Operational-Planned, 1980-2019
Zip file contains hourly wind profiles for operational/planned wind sites, profile development report, and wind site ID files.
(Aug 03, 2020 – zip – 116.4 MB) -
ERCOT Wind Profiles, Hypothetical Sites, 1980-2019
Zip file contains hourly wind profiles for hypothetical wind sites, profile development report, and wind site ID files.
(Jul 31, 2020 – zip – 122.1 MB) -
ERCOT Solar PV Profiles, 1980-2019
Zip file contains hourly profiles for operational/hypothetical utility-scale solar sites, hourly profiles for metropolitan/rural rooftop PV solar sites, profile development report, and solar site ID files.
(Jul 31, 2020 – zip – 124.2 MB)
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