Ideas abound for energy storage

As rural communities begin to develop wind and other forms of renewable energy, many are also pursuing energy storage devices to help integrate the systems with existing diesel generation and mitigate swings in energy production and demand.

Kotzebue Electric Association now has more than a megawatt of installed wind capacity, according to General Manager Brad Reeve. But wind power varies on a daily and seasonal basis, and diesel generators are turned on and off thousands of times a year to mitigate the swings.

To reduce the number of diesel starts and allow diesel generators to run at efficient levels when they’re on, the utility is planning to install a large “flow battery” that will be able to regulate power frequency and store excess power. Reeves said the battery, made by the Massachusetts company Premium Power Systems, will be able to provide 500 kilowatts for more than 7 hours, or roughly as much as is needed to meet the daily spikes in demand around breakfast, lunch and dinner. “We’re looking at using less diesel at the end of the day,” he said.

The Anchorage company Intelligent Energy Systems is working on several energy storage systems, including flywheels and heating units. CEO Dennis Meiners said flywheels can provide frequency regulation and an emergency power source to provide energy until a back-up generator can be started. The heating units are designed to provide frequency regulation and affordable space heating by capturing excess energy produced from wind turbines.

—Stefan Milkowski