Solar and wind energy costs have declined so dramatically in the past decade that they are now the cheapest of all forms of energy — cheaper than energy produced by fossil fuels, which pollute the environment and warm the planet. That reality counters the recent commentary by Ed MacNaughton and Clint Churchill, which was full of obsolete information used to draw the faulty conclusion that achieving 100% renewable energy is impractical for Hawaii (“Given what’s learned, maybe time to revise ‘100%’ policy, ” Island Voices, Dec. 4).

Cheap, clean, renewable energy is good news for consumers and good news for the Earth. Hawaii should move directly toward a 100% clean, renewable energy future.

Kauai Island Utility Cooperative (KIUC) has demonstrated that the low costs of clean, renewable energy translate to lower electricity rates for customers. In 2011, when KIUC was 92% dependent on fossil fuels, its rates were higher than those of Hawaiian Electric Industries (HEI), which generates electricity for the rest of the state.

Fortunately, KIUC embarked on an intensive effort to transition to renewable energy. Today, 60% of KIUC’s electricity is generated from clean, renewable sources, and KIUC’s rates are lower than those of HEI.

Fossil fuel prices are subject to wide fluctuation, while clean, renewable energy prices continue to drop. KIUC’s high percentage of clean, renewables buffered the impact of the recent spike in oil prices. The price of oil rose by nearly 75% between March 2021 and March 2022. During that period the average residential bill for HEI customers increased by about 30% because HEI is so dependent on fossil fuels — but during that same period, the average residential bill for KIUC customers increased by only 5%.

The Dec. 4 commentary made the groundless statement that “utility solar farms plus utility battery farms are clearly cost prohibitive.” Again, KIUC proves that the statement is wrong.

KIUC entered into a power-purchase agreement with AES Corp. several years ago, and AES built what was then called “the world’s largest battery plant paired with solar generation.” The facility produces cheap, clean energy and uses batteries to deliver power at night.

KIUC buys electricity from AES for 11 cents per kilowatt hour. Compare that rate with the 34.5 cents per kilowatt hour paid by the average HEI residential customer. Fortunately for its customers, HEI intends to expand solar generation with battery storage to bring down its rates.

As for liquefied natural gas (LNG), which the commentary endorsed as an intermediate step toward transitioning to 100% clean, renewable energy: that concept has been rendered obsolete by the drop in costs of clean, renewable energy. The cost of solar is now competitive with that of LNG, which is a fossil fuel. It makes sense to transition directly to solar.

Hawaii would be foolish to emulate a region — Caribbean countries and territories were cited as dependent on LNG for much or all of their power — that often experiences lengthy, widespread blackouts after hurricanes.

Two proposals that we agree would speed the transition to renewable energy? Rooftop solar should be encouraged in areas that are already urbanized, and efforts to collaborate with the military should be made.

Clean, renewable energy technology has advanced at a dizzying rate, resulting in costs that are plunging. For example, the costs of installing and operating large-scale battery systems declined 72% in a recent four-year period. It is not only possible for Hawaii to achieve a 100% clean, renewable energy future, but now we know that the resulting reduction in electricity rates will benefit consumers financially.

Bill Bugbee chairs and Melodie Aduja and John Kawamoto are members of the Clean Power Task Force.