Telematics-based Managed EV Charging: A pilot case study for utility bulk and distribution grid services

Growth in the EV market is resulting in an unprecedented increase of electrical load from EV charging at the household level. This has led to concern for electric utilities' ability to upgrade electrical distribution infrastructure at an affordable cost and sufficient speed that can keep up with EV sales. Adoption of EVs in the California market has outpaced the national average and offers early insight for other regions of the United States. The Sacramento Municipal Utility District (SMUD) partnered with two Distributed Energy Resource (DER) aggregators, the OVGIP (recently formed as ChargeScape) and Optiwatt, to deliver a vehicle telematics-based active managed charging pilot. This pilot was launched in Summer 2022, with approximately 1,200 EVs enrolled over two years including Tesla, Ford, BMW, and GM electric vehicles. The goal of this pilot was to evaluate the business case for mitigating EV grid impacts and delivering additional grid services providing both EV drivers and the electric utility additional value. The grid services tested included reducing bulk electrical system peak load, reducing service transformer overloads, and increasing consumption of solar generation to reduce solar curtailment. Location-specific day-ahead dynamic energy prices and customer-inputted charge preferences were used as an optimization objective to influence shifting of optimized charging schedules uniquely established for each EV. Use case tests were conducted in a Randomized Control Trial. A combination of statistical Energy Measurement & Verification (EM&V) techniques and Monte Carlo simulations were used to evaluate performance extrapolated to a 2030 grid and EV adoption scenario. The detailed experiment design, analysis methodology, and preliminary grid service performance results will be presented. Customer survey results indicating customer acceptance of managed charging and opportunities for improvement will also be shared.