California emissions rise on San Onofre shut down

05 November 2013

Greenhouse gas emissions from power plants in California increased by 35% in 2012, partly due to the early closure of the San Onofre nuclear power plant.

According to figures from the California Air Resources Board, carbon dioxide emissions from the state's power generation facilities increased from 30.7 million tonnes in 2011 to 41.6 million tonnes in 2012. Data shows that such emissions had been steadily declining between 2008 and 2011.

Total emissions from Californian electricity generation, oil refineries, cement plants and other industrial sources rose to 123.2 million tonnes in 2012 from 110.0 million tonnes in 2011. Meanwhile, when emissions from electricity imports and transportation fuel suppliers are included, total emissions grew from 429.3 million tonnes to 437.8 million tonnes.

The Air Resources Board said that the increase in emissions in 2012 was "primarily due to emission increases from California electricity generation using natural gas as a fuel." This was due to a decrease in available hydroelectric generation as well as the shut down of the San Onofre nuclear plant.

California power consumption rose 2.9% in 2012 to 234.9 billion kilowatt-hours, the highest since 2008 because of warmer weather and a recovering economy, according to grid operator California ISO.

Replacement steam generators intended to enable San Onofre units 2 and 3 to continue operating until 2022 were found to be suffering from excessive wear after less than one year in service. Both units were taken offline in early 2012 only to be closed permanently in June 2013 when Southern California Edison decided not to continue protracted regulatory processes.

As well as increasing emissions, the plant's closure has also impacted California's wholesale electricity prices. Over the first half of 2013, the US Energy Information Administration reported a 59% increase in wholesale power prices in the state, which it ascribes largely to the extended outages at the two units.

Two nuclear power reactors remain in operation in California at Pacific Gas and Electric's Diablo Canyon plant.

Researched and written
by World Nuclear News