The US Department of Energy has continued to push for the implementation of carbon capture measures in the energy sector despite emerging evidence linking sequestration technology to seismic events.
US energy secretary Ernest Moniz said at a carbon sequestration meeting in Washington DC earlier this month that power plants will be able to meet the Obama administration’s stringent standards for carbon emissions via the adoption of existing technology.
“The technology is ready,” he said. “Certainly all parts of the technology have been deployed at scale.”
Moniz also announced investment of close to $84 million in 18 projects to investigate second generation technologies for capturing carbon from coal-fired power plants, which are generally considered the worst culprits when it comes to air pollution and greenhouse gas emissions.
Despite concerted efforts to raise usage of clean energy sources over recent years, Moniz said the US economy will remain dependent on fossil fuels for the indefinite future, making measures to lower their carbon footprint critical for the environment.
“Coal and other fossil fuels still provide 80 per cent of our energy, 70 per cent of our electricity, and will be a major part of our energy future for decades,” he said. “Any serious effort to protect future generations from the worst effects of climate change must also include developing, demonstrating and deploying the technologies to use our abundant fossil fuel resources as cleanly as possible.”
Moniz’s remarks in favour of carbon capture arrived following criticism by GOP Members of Congress of Obama’s emissions regulations. The Republicans objected to the regulations, claiming they make excessive requirements of power plants and that the technology required for effective sequestration has yet to reach a sufficient state of maturity.
Another factor even more pressing than the lack of technological development, however, could threaten efforts to promote widespread adoption of certain carbon capture techniques. A pair of geoscientists from the US and China have uncovered strong evidence linking carbon sequestration measures to seismic activity and earthquakes, substantiating previous speculation about a relationship between the two.
A study published in the journal Proceedings of the National Academy of Sciences has isolated sequestration of liquefied carbon dioxide as a key causal factor in a series of earthquakes which beset the Cogdell oil field in Texas over a five-year period.
The study, by seismologists Wei Gan of the China University of Geosciences and Cliff Frohlich of the University of Texas-Austin, investigated the sudden onset of a rash of seismic activity in the west Texas oil field during the second half of last decade.
During the five-year period from 2006 to 2011, nearly 40 earthquakes with magnitudes of greater than 3.0 on the Richter scale hit the oil field, with the highest occurring in 2011 and measuring 4.4.
The flurry of earthquakes hit the area just two years after high volume injections of carbon dioxide commenced and, according to the two scientists, the timing of events would strongly suggest that carbon sequestration was a direct cause of the renewed seismic activity.
Frohlich said that while this conclusion should not bring an end to carbon sequestration projects, it should nonetheless prompt further investigation into the earthquakes risks posed by the technology in certain areas, including why it triggers seismic activity in some locations as opposed to others, and under what conditions is it safe to perform injections.