Hawaiian Electric and Stem, Inc. bring intelligent energy storage to Oahu

Helping businesses like Watanabe Floral save money while enhancing grid responsiveness

Watanabe Floral, a family-operated kamaaina company, has installed the first Stem Inc. energy storage system on the Hawaiian Electric Company grid to reduce business costs and help support grid stability as distributed solar generated electricity increases.


Hawaiian Electric and Stem are bringing energy storage and intelligent software to businesses on Oahu in a $2.1-million pilot program supported by Energy Excelerator, a program of the Pacific International Center for High Technology Research (PICHTR), Stem and Hawaiian Electric.

Watanabe Floral will shortly be joined by the Honolulu Museum of Art, Menehune Water and other Oahu organizations and businesses with a combined target of one-megawatt of energy storage on the customers' side of the meter.

Stem's data analytics software incorporates weather pattern information, past usage data and rate information to predict when electric use will peak. The system rapidly responds to spikes in electricity use, drawing on stored power to reduce costs for customers. Customers also receive access to Stem's software system that provides real-time visualization of energy use.

Stem's analytics will also begin to include data from Hawaiian Electric's current renewable forecasting and monitoring project.

When the combined Stem fleet of storage systems is installed, utility grid operators will be able to use the stored electricity for added stability during times of solar generation variability and peak demand.

"Watanabe has been providing flowers to the community and businesses of Hawaii for 69 years," said Leon Dodson, CFO of Watanabe Floral. "The Stem system helps us to monitor our solar panels and electrical demand load seamlessly to reduce our energy costs. We are thrilled that Hawaiian Electric is making this technology available to our business."

Watanabe Floral has entered into a standard interconnection agreement with Hawaiian Electric to connect its new 36-kilowatt energy storage system to the grid.

"We see energy storage supported by intelligent software as an increasingly essential component of our business," said Shelee Kimura, Hawaiian Electric vice president for corporate planning and business development. "Working with innovators like Stem, we will further modernize our system, integrate more renewables, and create a more stable and efficient grid for the people of Hawaii. This will allow us to reach our renewable goals as we serve our customers, better and at lower cost."

Behind-the-meter battery storage is experiencing strong growth in the U.S. But with only 6.4 megawatts of capacity installed in 2014, companies have barely touched the market's potential. Stem is one of a small number of companies leading the deployment of distributed energy storage in commercial and industrial buildings.

"Hawaiian Electric and the Energy Excelerator are speeding the adoption of cutting-edge energy technology to benefit the people of Hawaii, the environment, and the grid," said Tad Glauthier, Stem, Inc. vice president of Hawaii operations. "The rest of the U.S. is looking at Hawaii as a leader in renewables and grid modernization, and Stem is proud to be a part of this important transformation."

Hawaiian Electric and Stem are working together on this first-of-a-kind project through Energy Excelerator. The Hawaii-based startup program provided $1 million of funding and a platform to partner with the utility.

"This project is a perfect example of Hawaii at the forefront of energy innovation," said Jill Sims, Energy Excelerator demonstration track manager, who has been working with the utility and energy storage company. "Projects like this are transformative for companies like Stem and places like Hawaii. Innovation plays a key role in Hawaii reaching its aggressive energy goals."

When Energy Excelerator first encountered the Stem team in 2013, they had already installed energy storage systems with commercial partners in California, but had not partnered with utilities to help provide grid response. Shortly after being accepted into the program, Stem landed an 85-megawatt contract awarded by SoCal Edison. Stem continues to enhance dual support capabilities and bring cost savings to Hawaii customers and Hawaiian Electric as a collaborative team.

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