It’s been two years since Pacific Gas and Electric first launched its flexible interconnection program on the distribution grid. The program, dubbed “Flex Connect,” is designed as a workaround to getting distribution-level projects connected faster if they rein in their demand during peak hours.
Standardizing that offering, integrating it into PG&E’s distribution planning process, and then accelerating the pipeline has been a significant and time-consuming undertaking. The utility has brought a total of seven projects online successfully, two of which have now transitioned to firm interconnections thanks to grid upgrades.
The program rollout has been slower than the original forecast. PG&E originally hoped to have 10 sites online by the end of 2025, but ended the year with just five. That’s not due to one specific factor, said Alex Collins, a senior manager overseeing the program, but rather a variety of slowdowns including customer site construction changes.
But the Flex Connect pipeline is a much better lens for looking at how far the program has come, Collins said. Today there are around 85 sites that PG&E is assessing for flexible interconnection, and many of those represent “repeat customer interest,” meaning customers seeking flexibility for their entire pipeline of projects, he explained.
That’s partly why the vast majority of that pipeline remains EV charging sites — which is where the program originated — though there’s growing interest from “data center labs and advanced manufacturing sites,” he added. PG&E has received ten Flex Connect applications from those large load customers in 2026 alone, Collins said, which is a significant uptick.
An EV charger is a particularly good fit for Flex Connect because what the program is ultimately doing is reducing the maximum amount of power a site can use. Customers receive a firm floor, but a dynamic ceiling, up to the total amount of capacity requested, depending on grid headroom. That means as long as a customer isn’t operating at peak load most of the time, they aren’t really impacted by the flexible framework, Collins said. In fact, over the last two years, operating Flex Connect sites have actually had access to additional capacity — above their floor — 90% of the time.
Flex connect for large loads
Standardizing Flex Connect has required massive internal coordination, Collins acknowledged. When the pilot first started, for example, the fact that distribution planning and flexibility planning had distinct processes slowed implementation.
Planners were originally conducting studies without the flexibility consideration; a potential customer would receive a standard load limit letter, indicating the current maximum firm capacity for a site and the timeline for upgrades needed to increase that capacity. Then, for those requests that were eligible, the Flex Connect team would reach out with a second letter, sometimes months later.
During that time, customers might have dropped out from the queue or else moved on to other sites, Collins explained. Now, though, when customers get a response regarding firm load limits, they’re simultaneously informed about the flexible capacity available: “a single, coherent process,” Collins said. For EV charging sites, PG&E now includes flexibility analysis as part of the pre-assessment process, he added.
EV charging sites may be the low-hanging fruit for Flex Connect, but PG&E will also bring its first flexible data center site online this fall. That project, which is looking to connect to the distribution grid in the Bay Area, sits in the “sweet spot” for Flex Connect in terms of size, Collins said, which is about five MW.
Based on feedback from data center and manufacturing customers, PG&E also moved recently to integrate Flex Connect into its large load study process, which at the distribution level can include projects over two MW. The process can take months, because some projects also require a transmission impact study. Those large customers want to get connected quickly, Collins said, and proactively asked PG&E how quickly they could get flexible capacity, even if they have to wait longer for a firm connection.
Now, each stage of the large load process also includes a flexibility analysis, showing the fastest pathways to varying amounts of capacity.
That said, the majority of data center loads that PG&E is working with are connected to the transmission rather than the distribution grid. The utility is working to develop a transmission-level version of Flex Connect, Collins said, and is in discussions with data center developers about it.
Reducing cost and complexity
The last two years have also involved standardizing the tech stack for Flex Connect. In the early innings of the program, one of the biggest challenges was demonstrating to distribution planners that a site would reliably power down when needed: that a customer could receive PG&E’s day-ahead operating limits and that the onsite equipment would keep grid draw below that cap.
And doing so required a lot of site-by-site engineering at first: “We bootstrapped this by having a vendor willing to do a lot of custom work,” Collins explained.
Now that the company has roughly two years of operating data, the next challenge is making those capabilities repeatable and affordable. On PG&E’s side, much of the technology stack is the same across different types of loads, Collins added, but the equipment that controls power use on the customer side varies between verticals.
The team has therefore been taking a vertical-by-vertical approach, with the goal of establishing several “one stop shops” so that a customer can stick with the vendors they know, and avoid another recurring fee in order to participate in Flex Connect. Eventually, Collins said, PG&E expects to see “a whole new set of vendors” for the verticals.
The exception, he added, is front-of-meter commercial batteries, which introduce a separate set of technical complications because their controls must integrate not only with PG&E’s distributed energy resource management system, but also with the market systems that CAISO uses for bidding and dispatch. Those large, multimillion-dollar projects almost always opt for fully custom integrations, Collins said.
