Return to search

Mitsui & Co invests in Stem’s Series C round

Mitsui & Co. has led the first tranche of a $12 million Series C funding round in Stem, Inc, which provides energy storage. The investment will help Stem build out its grid services.

Press Release

Mitsui & Co., Ltd. (“Mitsui”) and Stem, Inc., (“Stem”) a leading U.S. provider of intelligent energy storage, today announced that Mitsui has led the first tranche of a Series C funding round of $12 million for Stem, Inc. The partnership will enable Stem to enhance its grid services offerings while creating a powerful partnership for international market expansion.

Mitsui and Stem plan to collaborate on Stem’s entry into new markets by leveraging Mitsui’s customer base and sales and marketing resources. Through this investment, Mitsui will contribute to the sustainable growth of Stem’s business as well as gain hands-on experience in the intelligent energy storage space.

“The value of customer-sited storage in grid-constrained regions is not exclusive to the U.S., as demonstrated by the increasing interest we’re seeing from some of the world’s largest energy players,” said John Carrington, CEO of Stem, Inc. “We look forward to working with Mitsui to enable the full spectrum of customer and grid benefits available from intelligent energy storage.”

“Mitsui has a rich history of strategic investments in businesses shaping our energy future,” said Hirohiko Miyata, General Manager of Power Projects Development Division at Mitsui & Co., Ltd. “The opportunity for distributed storage solutions like Stem is rapidly expanding across international markets, including our native Japan. We see much promise in the company’s unique approach to strengthen the changing grid landscape.”

Integration of renewables, grid instability and rising electricity bills are growing concerns in the U.S. and beyond. Distributed energy storage is playing an increasingly prevalent role in solving these challenges by helping businesses reduce energy costs while supporting grid operations. Stem combines predictive software with advanced energy storage to help businesses reduce energy costs with no impact to operations. When aggregated, Stem’s customer-cited energy storage network can serve as capacity in place of fossil fuel-based peaker plants, control voltage, enable demand response participation with no risk of fatigue, and offer a new set of customers a way to participate in grid services.

Mitsui envisions that Stem’s business model will expand throughout the U.S. and into international markets, delivering bill reduction and aggregated grid services that will ultimately materialize in a more efficient and cleaner electricity grid.

About Stem

Stem, a leading provider of intelligent energy storage, combines big data, predictive analytics and energy storage to simultaneously reduce electricity costs for businesses and in aggregate, deliver services to the grid. Stem’s software learns a customer’s unique energy profile to maximize savings and displays real-time and predicted energy use alongside actionable recommendations. When aggregated, Stem’s customer-sited storage network offers flexible, cost-competitive capacity to 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 New Energy, Total Energy Ventures and Mitsui & Co., Ltd. For more information visit

About Mitsui

Mitsui is one of the most diversified and comprehensive trading, investment and service enterprises in the world, with 142 offices in 66 countries. Utilizing our global operating locations, network and information resources, we are multilaterally pursuing business that ranges from product sales, worldwide logistics and financing, through to the development of major international infrastructure and other projects in the following fields: Infrastructure Projects, Iron & Steel Products, Mineral & Metal Resources, Integrated Transportation Systems, Chemicals, Energy, Food Resources, Food Products & Services, Consumer Services, IT & Communication and Corporate Development. Mitsui is actively taking on challenges to create new value through 360° business innovation. For more information, visit