The Energy Storage Report 2024

Now available to download, covering deployments, technology, policy and finance in the energy storage market

Stem’s virtual power plants take heat off Californian grid

By John Parnell
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.

This article requires Premium SubscriptionBasic (FREE) Subscription

Enjoy 12 months of exclusive analysis

  • Regular insight and analysis of the industry’s biggest developments
  • In-depth interviews with the industry’s leading figures
  • Annual digital subscription to the PV Tech Power journal
  • Discounts on Solar Media’s portfolio of events, in-person and virtual

Or continue reading this article for free

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.”

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.

Email Newsletter