well as a new gas-fired ….
well as a new gas-fired combined cycle gas turbines (CCGT), which began construction in 2017 and finished last year.
LW residents are familiar with the loud hissing and steam plumes that periodically erupted from AES in late 2019 as part of the commissioning of the new CCGT units.
This commissioning a new plant entails testing to ensure it meets design specifications and can operate safely and effectively. This includes the first fire of the gas turbines, the first times the units are turned on; steam blows; a steam purity run; and the initial steam turbine run before the final performance testing of the entire plant.
Steam blows are an important part of the commissioning phase due to their effectiveness in removing construction debris from newly installed steam systems, among other functions.
During a steam blow, steam is released from the steam tube system and vented to the atmosphere, creating the billowing plumes that were seen in LW.
A high-pressure steam release also creates a loud hissing sound. AES routinely sent company representatives to LW to explain the process as it unfolded from 2017 to the present.
Sound levels never violated the Seal Beach noise ordinance, and the steam blows were temporary and are not a part of normal operations.
Three of the six older units were retired in 2019, and the remaining three were scheduled to retire in 2020. However, in 2020, the California Public Utilities Commission passed a regulation saying the three remaining old water-cooled generators had to continue operation until 2023 as a backup for electrical supply.
Once that requirement is removed, AES plans to demolish the old generators and their tall exhaust towers that are visible on the LW skyline, especially from Clubhouse 2.
Compared to the old steam generators, the new plants improve efficiency and reduce emission rates; increase operating flexibility, enabling the integration of renewable energy; eliminate the use of ocean water for cooling; and reduce the use of fresh water by about 70 percent.
