LNG and Renewables Are Partners in the Energy Transition

O’ahu’s existing source of firming power is oil-based generation, which is expensive and high emitting. Meanwhile, aging power plants lack the reliability and flexibility to support the integration of significant new intermittent renewable generating capacity.

The Kahe and Waiau plants have an average age of 58 years, well-past their original designed lifespan of 30 years. Power outages on O’ahu have increased significantly over the past 10 years – particularly since the closure of the coal-fired Kapolei plant in 2022 – and these issues will only grow as the plants continue to age. That means in a future with abundant solar and wind, backup power from the Kahe and Waiau plants might not be available when called upon.

Age and outages aren’t the only problems with O’ahu’s existing oil-fired power plants. Kahe and Waiau are steam turbines, meaning they produce electricity by burning oil to boil water, which creates steam to spin a turbine. To keep the plant operating safely, a turbine needs to maintain minimum pressure and temperature just to stay operational, so it can’t ramp up and down easily (just think how long it takes to boil and cool water on your stove). O’ahu’s power plants take up to 12 hours to start up and shut down completely and typically need to operate at some minimum capacity around the clock.

What does that mean for renewables? Picture O’ahu’s oil power plants as an old steam ship – once running, it needs to keep on running or it will stall and take hours to restart. On a sunny day when renewable power is plentiful, that creates a problem: the oil plant still needs to operate, so the grid has more electricity than it needs. Grid operators are forced to turn off solar power plants, wasting the clean energy that was produced, to keep the grid running safely and reliably for homes and businesses.

Contrast that with a new LNG-to-power plant, like the one proposed by JERA. The new power plant won’t need hours to start and stop. It’s more like a car engine: it can start, idle, and accelerate quickly, but it can also be shut down on demand when it’s not needed on those sunny days. That means Hawaii won’t have to deliberately waste its clean solar and wind power as it reaches its renewables targets.

The flexibility and reliability of gas-fired power is particularly important given current cost and capacity limitations of batteries, which can hold 4 to 8 hours’ worth of electricity but cannot cover seasonal gaps or periods where solar and wind production are depleted for days or even weeks.

Sticking with oil puts O’ahu communities and businesses at risk of being left without power in times of need and wasting renewable generation during peak periods of production.

Switching to gas will help ensure O’ahu always has reliable generation at hand, while also maximizing the contributions of solar and wind.

The LNG that O’ahu would import to provide gas-fired generation is an enabler of renewables expansion rather than a displacer.

Other islands around the world have faced similar circumstances to O’ahu and used gas-fired power to support greater penetration of renewables.

Malta, an island nation in the Mediterranean with similar population as O’ahu, made the switch from oil-fired power to LNG in 2017. Renewables made up less than 5% of Malta’s energy in 2014 but by 2023 had reached 15% – comfortably surpassing the government’s original 2030 target. Malta is now planning offshore solar and wind facilities to complement strong growth in rooftop solar, with an updated target to have renewables make up 25% of the energy mix by 2030.

JERA has direct experience with gas-fired power supporting the expansion of renewables in Japan, where solar made up less than 1% of generation in 2010 and now provides nearly 10%.

The JERA-operated, gas-fired Futtsu Power Plant – one of the largest in the world and a key component of Tokyo’s metropolitan grid – has become increasingly flexible to support the buildout of solar power. When solar generation drops off in the evening or during cloudy periods, Futtsu quickly fills the gap. Futtsu now averages 2600 start-stops a year – a 20% increase from six years ago.