PG&E Flex Connect Links EVs to Grid Without Substation Wait
- EVs Infrastructure & Grid Connection Product
Marin Holt
- 0
- 6 minutes read
- PG&E launched Flex Connect in April 2025 to allow EV chargers and fleet depots to connect to constrained grid circuits immediately at reduced capacity.
- PepsiCo Fresno depot gained 4.5 MW of capacity 18 months ahead of schedule, adding 20 electric semi-trucks and saving $1M in fuel costs.
- Tesla Supercharger sites in Santa Nella and Upper Lake operate at 2 MW, throttled to 0.5 MW during peak grid events.
- PG&E had 5 live Flex Connect sites by April 2025, targeting 10 by end of year, with 35 site analyses per quarter.
- The DERMS platform was co-developed with Microsoft and Schneider Electric.
Pacific Gas & Electric launched Flex Connect in April 2025, a utility interconnection service that allows EV charging stations, electric fleet depots, and large battery systems to connect to the grid at reduced capacity without waiting for distribution infrastructure upgrades. Instead of queuing behind a two-year substation rebuild, a customer connects immediately at a lower power level, with the ability to draw full capacity outside of peak grid events.
Critical Perspective
Flex Connect requires participating customers to accept curtailment during peak grid events, effectively shifting grid capacity constraints from a utility infrastructure problem to an operational constraint on the customer’s facility. PepsiCo’s 4.5 MW Fresno depot connection at reduced capacity means electric truck charging schedules are constrained during CAISO summer heat events, precisely when freight demand and fleet utilization are highest. The program has not disclosed a compensation mechanism for energy not delivered during curtailment periods, nor has the CPUC formally approved Flex Connect as a permanent tariff structure rather than a pilot. For large fleet operators, the trade-off between an 18-month faster connection and accepting indefinite curtailment exposure requires financial modeling that PG&E’s program materials do not provide.
What Is Being Built
Flex Connect uses a Distributed Energy Resource Management System (DERMS), developed with Microsoft and Schneider Electric, to monitor real-time grid conditions and manage load in constrained areas. When the local feeder approaches its thermal limit, the system automatically reduces the customer's draw. When grid capacity is available, full power is restored.
PepsiCo's Fresno electric truck depot was the first major customer. Under a traditional interconnection process, the facility would have waited until mid-2026 for a substation upgrade to increase its capacity from 3 MW to 4.5 MW. Flex Connect granted the full 4.5 MW connection 18 months ahead of schedule. PepsiCo added 20 additional electric semi-trucks, reduced fuel costs by approximately $1 million, and cut roughly 8,000 tonnes of CO2 emissions as a result.
Two Tesla Supercharger sites, Santa Nella and Upper Lake in California, operate under Flex Connect with 2 MW of available capacity, which reduces to 0.5 MW during peak grid events. By April 2025, PG&E had five Flex Connect sites live and was conducting 35 site analyses per quarter, targeting 10 sites by the end of 2025. PG&E had installed more than 6,300 EV charging ports across its territory.
Why It Matters
EV fleet electrification timelines are frequently set by utility interconnection queues, not vehicle availability or depot construction. A single large fleet depot requires 3–10 MW of new capacity, triggering distribution upgrades that take 18 months to three years to complete and cost millions in ratepayer funds. Flex Connect collapses that timeline by accepting operational constraints during peak periods as a substitute for full grid capacity.
The model is reproducible. Other large utilities facing distribution capacity shortfalls, particularly in urban areas with high EV adoption, face the same tradeoff: slow, expensive grid reinforcement versus flexible, software-managed interconnection. PG&E's published results from Fresno and the Supercharger sites provide a documented performance baseline that other utilities and regulators use when evaluating similar programs in their territories.
California's EV adoption context makes the stakes concrete: 29% of new vehicles sold in the state in Q3 2025 were electric, and commercial fleet electrification is accelerating under CARB Advanced Clean Fleets regulations. Flex Connect positions PG&E to handle this load growth without a proportional increase in capital-intensive grid upgrades.
