(GreenBiz) After five years of rapid growth in rooftop solar, Hawaiian Electric has had to slow down new installations amid worries that more solar will destabilize power delivery in some neighborhoods. It's a looming issue for other places where a high penetration of distributed solar brings new challenges to how the grid operates.
The company that represents three Hawaiian electric utilities last week said that last year it reached 300 megawatts worth of rooftop solar from more than 40,000 installations, or about 10 percent of its customers on the island of Oahu. That's a huge jump from 2008, when only 12 megawatts were connected to the grid. And during hours of full capacity, distributed solar is contributing as much as a medium-sized power plant.
But the high penetration of solar is creating concerns for Hawaiian Electric. In some neighborhoods, solar panels generate more than the utility's daytime minimum load, a situation that the current grid equipment wasn't designed to deal with.
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