Power utilities in California have less than 12 years to meet the state’s transformational greenhouse gas reduction requirements – 40% below 1990 levels – for 2030. Southern California Edison is committed to the vision of a clean energy future for the state, and believes that large scale renewable energy and distributed energy resources (DERs) such as PV solar, energy storage, energy efficiency and demand management will be vital to reaching these goals.
A multi-disciplinary group at SCE led by our Transmission & Distribution Grid Modernization team recently made significant advances in mapping technology that will help integrate more DERs onto our distribution grid in the precise locations where they will provide the most benefit.
SCE is the first power utility to achieve large-scale implementation of this type of technology. The results promise to greatly expand opportunities for existing and future large-scale DER developers, with the potential to set off a wave of growth across the entire DER industry sector in California, and possibly nationwide. It will also help customers adopt DERs more easily and at lower cost.
SCE has a long history of solar innovation. SCE's Coolwater plant in the Mojave Desert — later named Solar One — began operation in 1982 as the nation's first large-scale solar electric generation site. The 10-megawatt facility was the largest plant of its type in the world, and the first commercial plant in the U.S. to use solar thermal technology.
Today, customers across our 50,000 square-mile service area are adopting DERs and becoming suppliers as well as consumers of power. By the end of 2018, more than 290,000 SCE customers had distributed solar connected to our grid. In 2018, SCE recorded 2,417 MW of capacity from behind-the-meter solar DERs; by 2025, we project that will grow 165% to 6,394 MW. SCE’s latest technology advancements will certainly factor into that growth.
Over the last year, SCE’s progress in mapping technology has enabled us to complete a systemwide Integration Capacity Analysis (ICA), documenting capacity attributes of each line section on our 90,000 miles of distribution lines. The ICA displays the maximum amount of DER capacity that can be connected on a specific line segment of our distribution system without adverse impacts such as overloads or voltage problems. We’ve concurrently developed a separate but related dataset, the Locational Net Benefit Analysis, that identifies the benefits (i.e., avoided costs of traditional infrastructure replacement or build-out) associated with meeting a distribution need in a specific location on the grid, expressed as $/kW per year.
The ICA, LNBA, and other related datasets comprise some 819 million records on a geospatial platform that the public can access through SCE’s recently launched web interface, the Distribution Resources Plan external portal (www.sce.com/drpep), which went live on December 28, 2018. The DRPEP enables large-scale DER developers, owners and operators alike to use the ICA and LNBA values (which are updated monthly) to find suitable interconnection locations for future projects. The developer, owner or operator of (for instance) a community solar project can use these tools to help streamline the interconnection process, reducing DER development time and costs.
Previously, that same developer would submit to SCE an application to interconnect their project to our distribution grid, thus initiating an SCE interconnection study. For the developer, the process lacked transparency until completion, when they would receive a final cost estimate from SCE. More challenging, the study would often take several weeks (or sometimes months) to complete, putting the developer’s project timeline or funding at risk. The new model flips that script entirely, putting critical planning information in the hands of large-scale DER developers upfront through a self-service web portal.
Publishing these 819 million records and updating them monthly is made possible through a feat of engineering, achieved through superior collaboration across multiple SCE functional teams as well as with external stakeholders.
"SCE’s progress in mapping technology has enabled us to complete a systemwide Integration Capacity Analysis (ICA), documenting capacity attributes of each line section on our 90,000 miles of distribution lines"
Integrating newly developed power analysis algorithms and methodologies, as well as robust IT systems assembled specifically for this purpose, SCE used the computing power of 42 on-premise servers to complete more than 23 billion load flow analyses, calculating the currents and voltages of every single line section, the fluctuation of load and energy consumption across monthly 24-hour periods (also known as 576 profiles) and calculating how much more generation and load can be installed at each of those locations. In three months, the servers recorded 5.67 years of processing time to complete the analyses.
Within SCE, the T&D Grid Modernization group received invaluable support from our IT, Distribution Engineering, and Real Properties teams. The entire effort began in response to an October 2017 decision by the California Public Utilities Commission, which ordered each of California’s investor-owned utilities to perform an ICA for each line section on its distribution system and to publish the results. SCE worked in close collaboration with the CPUC, the IOUs and with ratepayer advocates to agree on methodologies and standards to be implemented statewide.
From the start, the stakeholders recognized that the algorithms and methodologies should be non-proprietary, available to power utilities everywhere. Already, SCE’s third-party vendors on this project are marketing the algorithms off-the-shelf in other states; the hope is that widespread implementation, and the ensuing transparency of what electric grids can accommodate, will create new incentives for the nation’s power utilities to support DER adoption, and for large-scale DER development to blossom as a vital new industry.
Back in California, technological advancements like this are just one of the elements needed to reach the state’s 2030 GHG goals. It will also require infrastructure build-out, further advances in grid technology, changes in customer behavior, and broad stakeholder and policy support. Throughout the process, power utilities need to maintain safety and reliability and ensure cost-equity among all customers.
That said, SCE’s development of these analyses and technology is a major step in the path to meet California’s 2030 clean energy goals. It can serve as a roadmap for electric power utilities across the nation on how to bring more distributed resources online while maintaining grid reliability and resiliency and expanding available clean energy choices for customers.