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!

Read Next

Premium
December 11, 2025
Energy-Storage.news Premium speaks with John Farrell, Co-Director of The Institute for Local Self-Reliance (ILSR), on rising utility costs and the role energy storage can play.
December 10, 2025
NextEra Energy Resources and Meta have signed 11 power purchase agreements and two energy storage agreements totalling 2.5GW.
Premium
December 10, 2025
Clearway Energy Group has negotiated tolling agreements with SDG&E for one of its solar and storage complexes in Kern County, California.
December 9, 2025
In this Energy-Storage.news roundup, Energy Vault enters the Swiss energy storage market, ZincFive raises Series F financing, and Convergent Energy and Power secures a multimillion-dollar facility provided by NY Green Bank.
December 8, 2025
Vancouver-based helium and natural gas producer Desert Mountain Energy (DME) has signed a non-binding letter of intent (LOI) to form a joint venture (JV) to build and operate a sodium nickel chloride (SNC) battery manufacturing facility in Roswell, New Mexico.