More efficient, ocean-friendly natural gas generators have gone online ahead of schedule at AES power plants in Huntington Beach and Long Beach, although timing for demolition of older, larger stacks remains unclear.
While the state is moving toward a goal of carbon-free electricity by 2045, gas-fired plants continue to be essential, particularly during morning and evening hours when solar and wind energy is typically at a lull. The gas plants currently generate about a third of the state’s electricity.
Compared with the old units, the new generators are smaller, get much more energy from the same amount of gas and do not use ocean water for cooling, so do not harm sea life.
“But probably the most important asset is how fast they can start and stop,” said Stephen O’Kane, AES director of sustainability and regulatory compliance. Because gas-fired plants are needed primarily these days to fill the gaps when renewable sources lapse, the AES plants are used intermittently.
“The new turbine units can start in 20 minutes while the old steam generating ones could take 10 to 36 hours,” O’Kane said.
The new units went online Feb. 4 in Huntington Beach and Feb. 7 in Long Beach.
Old units at work
While the new generators are expected to be a key component of the state’s electricity for a decade or more, the Public Utilities Commission also is pursuing a plan to keep some old units running beyond their scheduled retirement at the end of the year. The goal is to minimize the possibility of power outages as the state transitions to green energy.
That means one old generator in Huntington Beach, known as Unit 2, could continue running, throwing a wrench in plans to begin demolition of the two old stacks in 2021.
“It is important to note that this (demolition) plan may be temporarily placed on hold should Unit 2 receive a short-term extension of life,” according to AES’s website. The site also notes that construction began in June 2017 and was completed three months ahead of time.
The two new stacks are about 15 feet shorter than the old ones and are set farther from Pacific Coast Highway. Additionally, screening is planned to further minimize the industrial appearance of the plant.
Helping drive the closure of the old coastal units — mostly built in the 1950s and 1960s — was a 2010 state policy phasing out use of ocean water to cool the generators, a decision made because ocean intake pipes kill small sea creatures and fish eggs.
But the move to the new, air-cooled technology was underway before the new policy, with updated units elsewhere in the state already in the works because of their dramatically improved efficiency. The new AES units in Huntington Beach and Long Beach are expected to produce twice as much electricity with the same amount of natural gas compared with the so-called “legacy units,” according to company officials.
Complaints
During trial runs of the new Huntington Beach generators in late 2019, some neighbors took to Facebook to complain that of loud noises.
“Those are part of commissioning and testing,” AES spokeswoman Dalia Gomez told the Orange County Register in January. “Noise levels should be similar to that of the legacy units.”
Yellow smoke from the new stacks, spotted at the Long Beach operations during testing in October, may have also been seen in Huntington Beach. Gomez said that smoke will not be emitted during normal operations.
AES has not taken a public position on whether to continue operating the old units, telling the PUC that it will do as the commission decides.
Natural gas use in 2018 accounted for 35% of the electricity generated in the state and renewable source made up 31%, according the California Energy Commission. That marked an ongoing trend that saw natural gas use in 2015 account for 44% of electricity and renewables making up 19%.
Additionally in 2018, the most recent year for which data is posted, large hydroelectricity provided nearly 11% and nuclear provided 9%.
