For five beautiful hours on Tuesday, December 10, the Hawaiian island of Kauai achieved total electrical generation from renewable sources. This marks a total of 32 cumulative hours over 11 days since November 22 that the island has run on 100% clean energy.

The generation came entirely from the Kauai Island Utility Cooperative’s (KIUC) renewable portfolio, which is comprised of a combination of distributed and utility-scale solar, a biomass plant and a number of relatively small hydro generation facilities. The grid supports an estimated 100,000 people, including visitors, roughly the same size as a large college football stadium.

The accomplishment is one of both pride and obligation for KIUC President and Chief Executive Officer, David Bissell.

“We want to provide the cleanest electricity possible, but we have to be mindful that our primary obligation is to provide safe, reliable power to our members at all times. Our operations personnel needed ample time to put all the necessary pieces into place before pushing the envelope to 100% renewable. Now we’re doing it routinely.”

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Kauai now joins the exclusive list of areas that have achieved extended periods of 100% renewable generation. It is the second American region to achieve such a feat. This past spring, the California Independent Systems Operator (CAISO) reported that, for most of the period between 1:50 PM and 3:05 PM on Sunday April 21, more CO2-free electricity was generated than users demanded in the region it covers. Put simply, California made more clean energy than it needed.

That news came just one week after CAISO reported instantaneous electricity generation of 11,011 MWac from solar power facilities connected to the transmission grid on Saturday, April 13, at 1:50 PM. When distributed generation was factored into that total, the number rose to at least 17 GWac of electricity generation coming from solar power. For a shining moment, the state hit 93% of demand with clean electricity.

Moving internationally, on February 22nd, 2017, Denmark generated enough energy with its wind turbines to power the entire country for the day for the first time. The generation clocked in at 97 GWh, the result of an especially windy day.

Just over a year later, Portugal’s renewable electricity generation for the month of March exceeded cumulative consumption for the first time, according to the nation’s transmission system operator. It was a goal that the country had come close to achieving in 2014, when renewable generation reached 99.2% and in 2014, when it achieved 100% renewable generation for a four-day stretch.

Rounding out the renewable five, comes Costa Rica, which may have the most impressive show of the bunch. The country has had multiple stretches of meeting energy demand entirely through renewables. On its worst day, the nation achieves 98% of its energy demand through renewable generation. As of this year, the share of renewables in Costa Rica’s power generation system reached 98.84%.