Solar meltdown in Paradise

On Sunday, July 20th, residents and vacationers in the beautiful paradise of Kauai suffered through a two-hour blackout as a convergence of events produced a “perfect energy storm” on the island.  

What happened on Kauai illustrates – on a small scale – what happens when renewable energy is forced onto the power grid to meet well-intentioned, but often impractical, carbon reduction mandates.

For nearly eleven years, our organization has stressed the importance of maintaining an affordable and reliable supply of energy as political trends push the integration into the grid of renewable energy. At our inception, that concern was based primarily on the “affordability” of electricity and the cost to consumers of new mandates. But, as the price of large or utility-scale wind and solar projects has dropped, our concern has turned to the reliability of the grid.

So what happened on Kauai in July to prompt us to write this cautionary tale?  

In short, the events leading to the blackout over July 20th and 21st were a “perfect storm.” On Sunday, July 20th, a cable snapped at Kauai Electric Cooperative’s 27.5 megawatt (MW) Kapaia gas-injected generating station, plunging Kauai into an island-wide blackout for more than three hours. Making matters worse, the cooperative’s other main generating station, Port Arthur, was out of service for necessary maintenance.   

Although the utility’s relatively advanced battery storage was able to quickly restore service to all 37,300 meters, the lack of available electricity production from its Kapaia and Port Arthur power stations required the co-op to institute rolling blackouts for the next several days in 30-minute intervals.  

The ultimate straw that broke the camel’s back though? The onset of cloudy weather. As the clouds moved into this most northwesterly island of the Hawaiian archipelago, power production from Kauai Electric’s utility-scale solar fell off the map. In a matter of moments, “behind the meter” commercial and residential solar systems weren’t producing enough, meaning businesses and homes on the island equipped with solar power suddenly found themselves relying on the grid. This added demand for power on a grid already stressed to its maximum was enough to break the grid.   

Through calls to cut back on power usage (also known as demand response), Kauai was able to weather the worst of this energy “perfect storm.” Still, Kauai Electric Co-op customers still faced rolling blackouts over a two-day period until the main power stations came back online and the clouds dissipated to allow for consistent solar generation.  

What can we learn from July’s rolling backouts in Kauai? First, building a robust grid is essential to keeping the lights on for customers. This means planning for scenarios where intermittent solar power simply doesn’t work. Second, regulators should recognize that the grid has both a cost and a value. Investing in a secure and reliable grid is not a matter to be taken lightly and customers, especially solar owners who are using the grid as a backup plan, should be paying fully for the value the grid affords them. The lessons are clear if we have the wisdom to learn them.