High-tech battery system helps conserve electricity

A high-tech battery company from California is installing $2.1 million worth of energy-storage systems at several Oahu organizations, including Watanabe Floral, the Honolulu Museum of Art and Menehune Water.

The systems help save energy by drawing from the batteries at times of peak energy use.

The software from Millbrae, Calif.-based Stem Inc. uses weather-pattern information, past-usage data and rate information to predict when electric use will peak. The system uses stored power when electricity use spikes. It can smooth out fluctuations in solar power and shift power from when it is generated to when it is needed.

“The Stem system helps us to monitor our solar panels and electrical demand load seamlessly to reduce our energy costs,” said Leon Dodson, chief financial officer of Watanabe Floral. “We are thrilled that Hawaiian Electric is making this technology available to our business.”

Stem, Hawaiian Electric Co. and Energy Excelerator, a nonprofit funded by the U.S. Department of Defense Office of Naval Research, are paying for most of the costs of the battery systems, said Peter Rosegg, a HECO spokesman.

“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,” HECO said.

Watanabe Floral, a family-operated kamaaina company, installed the first Stem energy storage system on the HECO grid.

“We see energy storage supported by intelligent software as an increasingly essential component of our business,” said Shelee Kimura, HECO 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.”

HECO said the so-called “behind-the-meter” battery-storage systems are growing rapidly in the U.S., “but with only 6.4 megawatts of capacity installed in 2014, companies have barely touched the market’s potential.”

Tad Glauthier, Stem vice president of Hawaii operations, said, “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.”