Stem’s virtual power plants take heat off Californian grid

By John Parnell
June 29, 2017
LinkedIn
Twitter
Reddit
Facebook
Email
The CAISO control room in Folsom. Image: CAISO.

Stem’s virtual power plants (VPPs) have been utilised to provide emergency demand response services in California during a major heatwave.

The networks, installed at a number of locations throughout the state, were used to meet increasing demand from air conditioning. The anticipated weather event created a spike in day ahead wholesale prices on 19 June, and a need to reduce demand or increase supply.

The services were provided to the California System Independent System Operator (CAISO) and three utilities.

“Stem proves again and again that we can step up immediately and deliver, right when the state or utility needs help,” said John Carrington, CEO of Stem. “When we are called, our network responds in minutes or less.”

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

On June 20, Stem provided power to seven strained areas of the network. The aggregated assets dispatched 1.6MW of power within five minutes. During the rest of the week, there were a further 10 dispatches as the heat wave, and its impact on the grid continued.

In California, Stem uses the CAISO Proxy Demand Response (PDR) mechanism to aggregate distributed energy generators, and has been an active participant in the wholesale market over the last three years.

24 March 2026
Dallas, Texas
The Energy Storage Summit USA is the only place where you are guaranteed to meet all the most important investors, developers, IPPs, RTOs and ISOs, policymakers, utilities, energy buyers, service providers, consultancies and technology providers in one room, to ensure that your deals get done as efficiently as possible. Book your ticket today to join us in 2026!
15 September 2026
San Diego, USA
You can expect to meet and network with all the key industry players again in 2025 from major US asset owners, operators, RTOs and ISOs, optimizers, software and analytics providers, technical consultancies, O&M technology providers and more.

Read Next

March 5, 2026
Developer Avantus has closed a financing package of over US$300 million for the 100MWac/130MWdc solar, 400MWh BESS Kitt Solar and Energy Storage Project in Pinal County, Arizona, US.
Premium
March 5, 2026
Energy-Storage.news Premium speaks with Claire McConnell, VP business development for Redwood Materials’ energy storage business, Redwood Energy, about its recent backing from Google and Nvidia, and what it has planned next.
March 5, 2026
From Texas, US, Bimergen Energy has acquired eight BESS projects totalling 79.2MW. Meanwhile, Habitat Energy announced its first US co-located solar-plus-storage partnership with Birch Creek.
March 4, 2026
Utility-scale battery storage developer Jupiter Power’s 700MW/2,800MWh Trimount battery energy storage system (BESS) in Everett, Massachusetts, US, has been approved by state officials.
March 3, 2026
3.6GWh of solar-plus-storage developments have progressed in Australia this week, with Edify Energy partnering with DT Infrastructure and Flow Power acquiring a 60MW project.