It’s a critical moment for VPPs, in which AI load growth, rising energy prices, extreme weather events, and technological advances have converged to create a “flywheel” effect, she added. “I can’t remember a time that it felt like the industry had more momentum and was more important to meeting broader [national energy] goals.”
The most visible evidence of the turning point has been the prevalence of emergency dispatches in 2025, Guernsey said. Before this summer, Voltus had seen one large PJM emergency dispatch in six years. So far this year they’ve already had at least eight.
Those types of dispatches have generally been thought of as “blunt instruments,” and that’s still partly true when compared to other types of services, Guernsey noted. But in addition to the number of dispatches, the “granularity and complexity” of the dispatches are also on the rise.
Dispatches are now regularly tailored by duration, location, and resource readiness, she added; a reflection of operational sophistication that is somewhat new in demand response.
Guernsey pointed to the power outage in the Baltimore area earlier this week as an example: When a transmission problem forced the Brandon Shores Power Plant offline from the BGE system, the local transmission network came under heavy strain, and electricity demand briefly exceeded local capacity. Even within that short emergency window, dispatches came in multiple waves based on resource readiness. “We’ll get dispatched for 120 minute resources, and then we’ll get dispatched for the 60-minute, and then ‘oh we still really need you guys for this 30 minute,” she explained.
More extreme weather events and massive load growth related to data centers and artificial intelligence are central to the rise in capacity-based dispatches for obvious reasons. But those same factors are also contributing to the rise of other types of services, including those that are leveraged much more regularly.
Ancillary services dispatches, including fast response from building controls and batteries, “contribute the most to filling in all of the 365 days,” she explained. As prices have come down for those assets, and the technology itself has improved, Voltus has seen the number of “fast response” dispatches growing.
“We went through kind of a lull in pricing there for a bit, especially in some of the reserves products, but they tend to ebb and flow with where natural gas pricing is and where prices in general are, and so those have rebounded,” Guernsey explained. “And so we see a lot of reserve pickup dispatches, operating reserves, and spinning reserves.”
Those services are becoming particularly critical in markets with high renewables penetration like the Southwest Power Pool. In SPP, which Guernsey calls “the least well-known, best postcard from the future,” wind penetration can exceed 90% on some days. As grids push into those high penetration numbers, volatility spikes. Short bursts of operating and synchronized reserves from VPPs are indispensable in those cases, Guernsey said. Voltus, for example, dispatches those types of assets at least once a day in SPP, for between 10 and 20 minutes at a time.
“As the grid moves towards a more renewable system, that necessitates a little bit more the use of those balancing resources,” Guernsey said. Voltus’s dispatch data certainly suggests that to be the case, she added.
Making demand response pencil
The shift isn’t just technical: Over the last year, state policies and market operator rules have started to treat VPPs as core reliability resources. Guernsey pointed to New York ISO, which is advancing market reforms that increasingly integrate VPPs and aggregated resources on a level playing field with traditional generators. A handful of states have advanced legislation and mandates pushing utilities to plan for and rely on aggregated demand-side resources to meet system needs.
“They’re treating us more like traditional generators, which is a good thing in the way we want markets to go,” Guernsey said.
In July, California grid operator CAISO and PG&E coordinated what they billed as the largest-ever test of VPP capabilities. Using Tesla’s and Sunrun’s VPP program, they delivered more than half a gigawatt of flexible power into the grid.
Energy services, the third type of dispatch where Voltus has seen immense dispatch growth over the last year, is extremely price sensitive. But it also relies on customers having energy top of mind — the average consumer might not even know that curbing their energy use on a granular, device level basis is an option.
Customers need to be “more connected to their energy spend and energy bills” to be open to participating in energy services, Guernsey said.
Today that engagement is on the rise, largely because energy prices are so high, and the high-profile AI boom has the potential to push those prices even higher.
“When energy was not a big part of their spend or it wasn’t such a pain point, maybe they didn’t consider it,” Guernsey added. “Maybe the inflection point for them is now crossed…you can start to cross these thresholds of things penciling in a new way.”
