The federal government has awarded $2.1 million to the state Department of Business, Economic Development and Tourism to build energy storage systems that will allow electric utilities to accept more renewable energy.

DBEDT said it will allocate $1.2 million of the total to Maui Electric Co. and $900,000 to Hawaii Electric Light Co. on the Big Island. The funding will be used to build energy storage systems that will help smooth out the ebbs and flows of electricity to the grid from renewable sources, such as wind and solar. Interconnection costs will be paid by the utilities.

Battery technology is the primary method for storing electricity generated by renewable sources, but other options are available, including compressed air, pumped-storage hydroelectricity and flywheels.

"These Department of Energy funds are intended to expand renewable energy use across the Hawaiian Islands," U.S. Department of Energy official Steve Lindenberg said in a news release.

"The two storage projects will help answer many questions related to areas of dense solar applications. We look forward to the results being helpful throughout the state," said Lindenberg, a senior adviser for renewable energy with the DOE.

Ted Peck, administrator of the state Energy Office, said the storage system research will help the state achieve its goal of generating 70 percent of its energy from clean sources by 2030.

"Hawaii’s abundant renewable energy resources are widely distributed across the islands, therefore, incorporating steadily increasing amounts into our grid system is going to require a proactive approach," Peck said.

Installation of the energy storage system projects is expected in the second half of 2011.

For Maui County, one project will focus on the Molokai grid, where the Kaunakakai circuit has reached a 15 percent "feeder penetration limit" set by the state Public Utilities Commission for the amount of electricity that can be accepted from renewable sources. Maui Electric will perform an interconnection study on a single circuit to identify any system upgrades required to allow more photovoltaic generation to be added to the circuit.

"This stimulus grant will allow Maui Electric to understand the value of using battery systems to support more photovoltaic solar power and other distributed energy for our customers while maintaining the essential reliability our customers count on," said Ed Reinhardt, Maui Electric president.

Another project will be located on the Big Island, where renewable sources supply more than 30 percent of the island’s electricity.

"With Hawaii island having the highest penetration of renewables such as geothermal, wind, hydroelectric and photovoltaic, evaluating energy storage is a key element to HELCO integrating more distributed renewable energy generation," said HELCO President Jay Ignacio.