History
In 1949, Pacific Gas & Electric (PG&E) began construction on the Moss Landing Power Plant. Five natural gas and oil powered steam units were built during the 1950s. Commercial generation started in 1950 with a capacity of 613 MW.
In 1964, the construction of two additional units began (6 and 7), with two new 500 ft stacks. These two units had a capacity of 750 MW each for a total of 1500 MW, with 180 ft tall boilers. They employed a newer technology using supercritical steam at 3600 psi.
In 1995, the original five units were retired, and in 1997 PG&E let the permits lapse for these units.[4][5]
As part of the Deregulation of Utilities in California, PG&E sold the plant to Duke Energy (DENA) in 1998. To comply with more restrictive pollution regulations, units 6 and 7 were upgraded in 1998 with a selective catalytic reduction unit and digital control systems.
Starting in 2000, the eight 225 ft stacks and 19 fuel oil storage tanks were removed, and two new units were built on the former site. The new units 1 and 2 were brought online in 2002. They are combined cycle units, 50% more efficient than the other units, because they use two turbines: first, a pair of 170 MW gas turbines, then a 190 MW steam turbine, for a total of 530 MW each. When completed in 2002, the plant was the largest power plant in California by capacity, at 2560 MW.[6]
In 2006, having invested over half a billion dollars in upgraded capacity, efficiency and emission control, Duke Energy sold the plant to LS Power Equity Partners.[7][8] Dynegy purchased the plant in April 2007 along with other assets of LS partners.[9]
In 2015, a transmission tower collapsed at the power plant, causing a major Monterey County area power outage.[10]
On December 31, 2016, Dynegy retired supercritical steam units 6 and 7 as they were no longer economically competitive. Dynegy continued to maintain the permit on these units.[11] The facility was being dismantled in 2023.[12]
In February 2017 Dynegy announced that it may close Moss Landing, due to market conditions resulting from a glut of wholesale electricity capacity in California making it difficult to operate profitably. By 2018, California had 7,000 MW of surplus generating capacity, but a similar amount (mostly ocean cooled) would be retired by 2021.[13] The glut in electricity capacity is partially a result of policies which guarantee utilities like PG&E (a regulated monopoly) a return on investment for building new power plants, even when they are not needed. Independent power producers like Dynegy, on the other hand, did not have a guaranteed return on their investment.[14] Power production had dropped considerably, reducing taxes paid to Monterey County.[15]
On April 9, 2018 Vistra Corp merged with Dynegy Inc, and thus also acquired the Moss Landing Power Plant.[16] Vistra opted not to close the Moss Landing plant, but instead to expand it.[17] In 2021 Vistra began to refer to its Moss Landing power plant facility as the "Vistra Moss Landing Energy Storage Facility".[18]
