This summer, San Diego Gas & Electric (SDG&E) is reminding customers that, while adequate electricity supplies are available to meet regional energy needs, conservation and demand response will still be vital during heat waves or an unplanned power plant outage or transmission line emergency.
Summer began early this year with heat waves beginning in May, and SDG&E customers helped do their part to keep the electric grid running smoothly by responding to calls for conservation during the wildfires in the northern part of San Diego County. With the San Onofre Nuclear Generating Station (SONGS) permanently offline and the potential for summer heat waves or wildfires, Southern California may face another tight summer for electric resources.
The Sunrise Powerlink continues to increase reliability and improve Southern California's ability to import power, particularly from new renewable generation projects in Imperial Valley. SDG&E has increased the reliability of the local grid over the past year with several major transmission system enhancements as well as continuing to coordinate with the California Independent System Operator Corporation (California ISO) and Southern California Edison on contingency plans for adequate electricity resources for customers throughout Southern California without SONGS in operation.
The California ISO, responsible for managing the bulk of the state's power grid, recently issued its 2014 Summer Assessment that predicts an adequate supply of electricity for meeting summer peak conditions across the state despite well below average hydroelectric supply.
The assessment identified local reliability concerns focused on southern Orange and San Diego counties during extensive heat waves but reliability levels are still within operating standards. There is an estimate of 54,171 MW of power plant capacity available this summer within the ISO grid, including new generation of 3,644 MW and an additional 117 MW expected to come online by July 4. About 61 percent of the new power supply comes from solar power with about seven percent from other renewables.
As the weather continues to warm up, energy use typically increases due to increased use of air conditioning. Despite having adequate electric resources, conditions may change anytime due to unexpected situations that may be out of SDG&E's control. High energy use during summer heat waves or electric transmission emergencies can have severe impacts on SDG&E's ability to deliver power.
Since 2012, SDG&E residential customers have been able to earn a bill credit for saving energy on specific days through Reduce Your Use Rewards. These Reduce Your Use days may be called on hot summer days when energy demand is high.
SDG&E also recently launched the Reduce Your Use Thermostat program that provides programmable communicating thermostats to eligible business and residential customers free of charge, and enables customers with the thermostats to receive a higher bill credit on Reduce Your Use Rewards days. The connected thermostats, either through Wi-Fi or connected to customers' smart meters, are able to receive a signal directly from SDG&E on Reduce Your Use Rewards days.