Stem Energy Storage Network Delivers Emergency Grid Relief in California Heat

Stem repeatedly over-delivers committed demand reductions for the
state grid during heat wave

MILLBRAE, Calif.–(BUSINESS WIRE)–Stem Inc. activated several of its virtual power plants, networks of
energy storage systems located at business and institutions throughout
the state, multiple times during an unprecedented heat wave last week,
automatically dispatching stored energy to provide emergency Demand
Response services to the California System Independent System Operator
(CAISO) and three major utilities.

As a major heat wave approached California on June 19, 2017, energy
prices in the day-ahead wholesale market rose significantly, signaling a
need for resources that could act quickly to increase energy supply or
reduce demand in order to prevent widespread blackouts. Having regularly
offered stored energy from its network into the CAISO markets since
2015, Stem’s latest bids started to clear.

Stem first committed to reduce energy demand for Pacific Gas & Electric
(PG&E) and Southern California Edison at 5 pm PT on June 20 through the
Day-Ahead settlement process the night before. Then at 5:15 pm on June
20, while already dispatching in four areas within the PG&E and SCE
service territories, additional Stem offers to provide energy with less
than five minutes notice were accepted further south in three parts of
San Diego Gas & Electric’s (SDG&E) service territory. Stem stepped up,
dispatching energy storage systems at customer locations across seven
utility zones to deliver on-time and more than promised.

In this one hour, Stem delivered stored energy from its customer network
to seven strained areas of the CA grid simultaneously at the height of
an unprecedented heat wave. Acting as virtual power plants, aggregations
within the Stem network automatically responded to rising wholesale
prices in as little as five minutes to dispatch 1.6 MW of targeted
relief, 21% more than committed. Stem’s network similarly dispatched
fast, on-demand power 10 more times across the three utilities’ service
territories in the remainder of the week as the heat continued.

“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.”

In California, Stem uses the CAISO Proxy Demand Response (PDR) mechanism
to aggregate DERs, and has been a very active participant in their
wholesale market over the last three years. CAISO prices have cleared
higher than the bids of storage-based demand response providers more
frequently than expected in 2017. For example, Stem’s network responded
to 150 “real-time,” or five-minute dispatch events for SDG&E from
January to May of 2017. Stem is the leader in bidding aggregated
distributed energy resources (DERs) into wholesale markets in California
and across the U.S.

Stem
Inc., the global leader in commercial-scale intelligent energy
storage services, provides storage-as-a-service
to commercial and institutional customers and is backed by the
industry’s largest project finance pool at $350 million. Stem delivers
predictive analytics software to get real-time and future usage and cost
data for customers to improve overall efficiency. Customers pay a
monthly subscription fee and on average save two to three times what
they pay for the service. Reducing commercial peak demand helps improve
local grid stability and distribution energy planning.

About Stem, Inc.

Stem creates innovative technology services that transform the way
energy is distributed and consumed. The company’s mission is to build
and operate the largest digitally connected energy storage network for
our customers. Our world class analytics optimize the value of
customers’ energy assets and facilitate their participation in energy
markets, yielding economic and societal benefits while decarbonizing the
grid. Headquartered in Millbrae, California, Stem is funded by a
consortium of leading investors including Angeleno Group, Iberdrola
(Inversiones Financieras Perseo), GE Ventures, Constellation Technology
Ventures, Total Energy Ventures, Mitsui & Co. LTD., RWE Supply &
Trading, and Mithril Capital Management. Visit www.stem.com
for more information.

Contacts

Antenna Group for Stem, Inc.
Josh Garrett, +1 646-357-3445
[email protected]