Duke Energy is investing $30 million into the two biggest battery storage projects in North Carolina -- a first for the regulated arm of the Charlotte-based utility. “We feel the technology has improved, the price has come down, and we think there are some niche applications where battery use makes sense for the regulated utility,” said Duke spokesperson Randy Wheeless. “In a regulated environment, you have to justify these projects to a commission, and usually least cost is an overriding factor there.” The projects may indicate new interest in storage among regulated utilities, as battery prices continue to fall.