Demand Graph and Data
Current System Demand is a snapshot of the total system load from the ISO Energy Management System. The figure is updated every 10 minutes. Because it is only a snapshot, figures reflected on this page may not capture actual peak system load.
Today’s Peak Demand reflects the peak load to this point in time of the 10-minute snapshot of the load displayed in the Current System Load. It may not reflect actual Peak Demand for the day.
Today’s Forecast Peak Demand reflects the forecast peak load for the day.
Tomorrow’s Forecast Peak Demand reflects the forecast of peak load contained in the California ISO OASIS web site under the System Load tab. It is adjusted as a new one-day forecast is published.
Demand graph shows the Current System Demand 10-minute snapshot figures plotted against the forecast demand. The demand forecasts are based on historical system loads and temperatures and represent in megawatts the expected system load for each hour of the day. The Day Ahead Demand Forecast is performed prior to running the day ahead market. The Hour Ahead Demand Forecast is performed each hour prior to the hour ahead scheduling process.
Automating Access to Today's Outlook data
If you are interested in re-publishing information from this page, access a comma-separated value (CSV) file here.
Renewables graph shows the aggregated output from the wind, geothermal, biomass, biogas, small hydro and solar generation connected directly to the California ISO balancing authority. The graph is intended to depict how much renewable energy is produced in the balancing authority and the need to track and compensate for the variability in production.
Alerts, Warnings and Emergencies
Emergency notices are issued when operating reserves or transmission capacity limitations threaten the ability of the California ISO to safely and reliably operate the grid or energy markets through normal modes of operation.
Transmission Emergency notices are issued for events that threaten, harm or limit the capabilities of any element of the transmission grid and threaten reliability.
Restricted Maintenance Operation notices are declared when routine maintenance on transmission lines or power plants could threaten grid reliability.
Alert notices are issued one day before ISO may require extra resources to avoid electrical emergency.
Warning notices are issued hours in advance of when there may be a shortfall. Requests for conservation issued. Voluntary load reduction programs may be triggered at this point.
A Stage 1 Emergency is called when the minimum required operating reserve level falls or shortfalls are forecast to occur and available resources are insufficient to maintain the operating reserve requirement. Under a Stage 1 Emergency, the ISO calls for conservation and will activate a Flex Alert if necessary.
A Stage 2 Emergency is called when the minimum non-spinning reserve requirement cannot be maintained. Under a Stage 2 Emergency, the ISO can call on “interruptible” programs operated by the utilities. Typically, participants in these programs are commercial and industrial customers who receive a lower electricity rate in exchange for reducing their energy usage by a predetermined amount when called upon during a Stage 2 Emergency.
One Hour Notification of Probable Load Interruption notices are issued to the utilities, public safety agencies, the media, regulatory agencies and market participants when a Stage 3 Emergency and rotating outages are deemed probable.
A Stage 3 Emergency is called when the spinning reserve is depleted or is anticipated to fall below minimum requirement. Under a Stage 3 Emergency, the ISO may call on the utilities to reduce “firm load” by implementing rotating outages. This is a last resort, used only when a climbing demand for energy is close to surpassing the available supply.
Flex Alerts inform consumers about how and when to conserve electricity. This conservation is critical during heat waves and other challenging grid conditions. Go to the Flex Alert tips page for more information on how you can help.
Today’s Outlook is not used by system operators to operate the ISO control area because it does not have the capability to represent real-time system operating conditions, nor is it intended for that purpose. The forecast values are based on the best information available at the time. Also be mindful of variations or inconsistencies in the data due to data quality or data transfer timing issues. Please refer to the California ISO Open Access Same-time Information System (OASIS) site at http://oasis.caiso.com
for official published data.
All trend and tabular values are updated every 10 minutes. Please refresh your screen periodically as this page does not refresh automatically.