Can Stem Energy Storage Boost Hawaii Solar?

Utilities seem worried that unpredictability is the fatal flaw of distributed generation. But solar storage can already soothe that unnecessary concern, as utilities are finding out themselves. Especially in solarized, polarized Hawaii, whose (mostly) lone utility Hawaiian Electric Industries has partnered with California-based Stem for 1 megawatt of behind-the-meter emergency backup.

“The success of the solar industry in Hawaii is a blessing and a curse,” Stem’s vice-president of Hawaiian operations Tad Glauthier told SolarEnergy. “Local grid operators have to deal with unpredictable generation and potentially reverse power flow at the substation level. These factors make it a natural fit for Stem’s advanced energy storage systems and predictive analytics. Given our focus on commercial and industrial customers, we have a unique opportunity to help the utility balance renewables on the electric grid, while also reducing energy costs for businesses on Oahu.”

Speaking of cost blessings and curses, renewable energy pledges from HEC have lately been accompanied by reminders that early rooftop solarizers will have to pay more. Hawaii has also lately lost thousands of solar jobs, as permitting has dried up in advance of HEC promises to boost its renewable portfolio by 2030. As hot as the Hawaii’s solar market has been, “interconnection continues to be an issue as Hawaiian utilities have imposed restrictions to avoid solar generators’ loads on their systems,” SEIA explains.

Perhaps HEC’s deal with Stem will settle accounts. It arose out of a $1 million grant from Energy Excelerator, a HEC collaboration with the U.S. Department of Energy and Department of the Navy. Glauthier tells SolarEnergy Stem is optimistic about its plan to deploy systems at targeted Oahu commercial and industrial buildings by March 2015, then flip the switch and wait for unpredictability to strike.

“Hawaiian Electric will be working closely with Stem to identify specific customers, focusing on areas with major grid congestion,” he explained. “Many commercial and industrial facilities pay demand charges for setting a peak level each month, like being charged for miles driven in a car and also for the top speed you drive for the month. Flattening the peaks makes it easier and cheaper for utilities to respond rapidly to spikes in customers’ electricity demand — which is expensive, because a power plant has to be sitting there, waiting to serve the load. Stem batteries reduce demand charges without impacting operations.”

Stem is also storing and starring on the mainland. Earlier this year, the company became the first to participate in the aggregated, behind-the-meter energy storage market in Northern California after installing Stem systems in hotels and other facilities. By removing unpredictability from HEC’s list of things to worry about, perhaps Stem’s seamless solar power backup plan can help jumpstart the utility’s renewable energy agenda back to where it needs to be.

“This partnership helps ease the integration of more solar energy onto the grid by giving Hawaiian Electric additional tools to more effectively manage its assets,” Glauthier said. “This model can be applied in geographies across the U.S., especially in regions where legislation is encouraging wider use of storage. Participating customers can often receive financial incentives from their utility to join grid support programs.”

“Hawaiians know that diversifying energy sources and driving down costs is critical to a healthy economy and environment,” he concluded. “Aggregated distributed storage can go a long way toward helping Hawaiian Electric adapt to an evolving grid, and ultimately catalyze the spread of solar energy in Hawaii.”

This article appeared at Solar Energy