Stem Distributed Storage Will Strengthen Hawaii Grid Response

The Stem system

The Hawaii electric grid is about to get much smarter. Stem, a provider of advanced energy technology, will help make this happen.

Stem plans to deploy 1 MW of behind-the-meter energy storage in a demonstration project with Hawaiian Electric (HECO) to support grid response services. This is crucial in grid-saturated Hawaii, where 10% of homeowners on Oahu already have solar systems.

That causes issues for the grid. As more distributed solar comes on to the grid, demand drops during the mid-afternoon, when the sun is shining. Then, when people come home in the evening and the sun goes down, there’s a big spike in demand. It’s hard to ramp up traditional power plants quickly enough to meet this quick spike.

Stem’s energy storage and data analytics help by predicting and rapidly responding to demand spikes — and drawing on stored power at those times. That avoids relying on the traditional power plants to ramp up quite so quickly, and so reduces energy costs without affecting operations.

Stem will manage its advanced energy intelligence solution for commercial and industrial customers throughout Oahu. The aggregate portfolio of energy storage customers will provide additional grid capability during periods of variable solar generation and peak demand.

Another advantage of Stem’s technology is that it leverages the renewable forecasting and monitoring project that HECO currently operates. Customers who participate will receive financial incentives to provide grid responsive power while supporting clean energy on the grid.

While this pilot project is relatively small, this kind of effort could be huge for Hawaii, and set a precedent for the rest of the country. Stem says its deployment will support the transformation of the Hawaii electric grid from one dependent primarily on fossil fuels to one that incorporates large amounts of solar and wind.

“Hawaii’s renewable energy growth and isolated location present unique and significant challenges for local grid operators,” said John Carrington, CEO of Stem. “Utilities and regulators are watching Hawaii to determine the viability of storage-enabled grid services. We are proud to be working with Hawaiian Electric to address those grid challenges with our technology.”

HECO and Stem will work together to identify and enlist commercial and industrial customers with rooftop solar systems. All installations are expected to be completed by March 2015.

“We see energy storage supported by smart grid software as an increasingly essential component of the modern grid,” said Alan Oshima, incoming president & CEO of Hawaiian Electric. “Through partnerships with innovators like Stem, we will further modernize our system, integrate more renewables, and better serve our customers at lower costs.”

The program is supported by $1 million in grant funding from Hawaii’s Energy Excelerator, which was created to commercialize game-changing energy technologies in Hawaii’s unique test bed, and help companies scale globally.

“Stem is unique because of their dual impact. They aren’t just reducing costs for individual buildings; they also knit together multiple batteries to enable the integration of more renewable energy system-wide,” said Dawn Lippert, Director and Co-Founder of the Energy Excelerator. “We’re excited about what this means for the future of Hawaii and other markets.”